Dihexa.co.uk

Welcome and introduction to Dihexa.co.uk

Introduction to Dihexa: definition, structure, classification, and basic information

How Dihexa is thought to work at the molecular and cellular level

Evidence-based overview of potential benefits based on preclinical and clinical research

Summary of scientific evidence, clinical trials, and current research status

Development history, clinical trials, and corporate context of Dihexa research

Dihexa's potential application in Alzheimer's disease and neurodegenerative conditions

Information on dosage ranges, protocols, and considerations for research use

Comprehensive overview of potential adverse effects, safety concerns, and risk factors

Dihexa in the context of cognitive enhancement and nootropic use

Comparative analysis of Dihexa against other nootropic compounds and peptides

Detailed analysis of Dihexa's legal status under UK law and regulatory framework

Comprehensive guide to buying research chemicals: quality, testing, COA, red flags, and best practices

Definitions of 30+ key terms: synaptogenesis, BDNF, LTP, blood-brain barrier, and more

Answers to common questions about Dihexa, research chemicals, and safety

In-depth guides and articles on Dihexa, nootropic stacking, peptide science, and cognitive enhancement

Rigorous 2026 UK evidence review of whether a synaptogenic HGF/c-Met peptide like Dihexa has any role in Hashimoto's thyroiditis, primary hypothyroidism, subclinical hypothyroidism, autoimmune thyroid disease, treated hypothyroidism with residual brain fog, euthyroid antibody-positive Hashimoto's, post-partum thyroiditis or any thyroid-related cognitive symptom. Covers Hashimoto's as the most common autoimmune disease in iodine-sufficient countries (Mavroudis 2025 Medicina scoping review: 4.8-25.8% in women, 0.9-7.9% in men, female-to-male ratio 2-7x; 2-3% of UK adults treated for hypothyroidism with a further 4-10% in the subclinical range); the substantial brain fog burden (memory disorders ~24%, slow thinking ~22%, fatigue ~18%; >95% of patients list forgetfulness, fatigue, sleepiness and lack of focus among core symptoms; ~10% of levothyroxine-treated patients have persistent brain fog despite normal TSH); the October 2025 NICE NG145 exceptional surveillance decision retaining levothyroxine as first-line and declining to update the recommendation against routine liothyronine (T3) alone or in combination, with the research recommendation around DIO2 polymorphism and persistent symptoms remaining open; the NHS England Regional Medicines Optimisation Committee guidance constraining new T3 initiation; the T3-BDNF axis in the hippocampus — the 2016 Endocrinology Camilo paper on mild developmental thyroid hormone insufficiency compromising activity-dependent neuroplasticity into adulthood; the 2021 Sui PMC paper on absence of thyroid hormone causing delayed dendritic arborisation in primary hippocampal neurons through insufficient BDNF expression; the 2021 Leyhe Scientific Reports Hashimoto's thyroiditis event-related potentials (ERP) and magnetic resonance spectroscopy (MRS) study showing prolonged N200 and P300 latencies, reduced P300 amplitude and cognitive correlation; the 2018 Krysiak Medicine (Baltimore) low vitamin D and cognitive impairment in Hashimoto's association; the DIO2 Thr92Ala deiodinase polymorphism and brain-T3 question; Hashimoto's encephalopathy / steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT) and the 2025 Biomedicines and 2025 Frontiers in Psychiatry reviews with the >2-year persistent cognitive deficit picture despite corticosteroid therapy; the absorption pitfalls (food, coffee, calcium, iron, PPIs, MHRA brand-consistency considerations); the c-Met / papillary thyroid cancer oncology concern in a population with elevated thyroid-nodule risk; British Thyroid Foundation (BTF), Thyroid UK, British Thyroid Association (BTA) and NHS underactive thyroid pages as UK patient-facing resources; co-existing coeliac disease (~5%), vitamin D deficiency, iron / ferritin / B12 / folate deficiencies as treatable imitators; obstructive sleep apnoea overlap in hypothyroidism; perimenopause / menopause overlap as a midlife confounder; the fosgonimeton (ATH-1017) Athira LIFT-AD Phase 3 failure as a cautionary clinical analogue; the BDNF-synaptogenesis Benoist 2014 JPET Dihexa pharmacology paper; and the complete absence of any human Dihexa trial data in any thyroid, autoimmune thyroid, hypothyroid, Hashimoto's, Graves' or thyroid-related cognitive population.

Rigorous 2026 UK evidence review of whether a synaptogenic HGF/c-Met peptide like Dihexa has any role in endometriosis, endo brain fog, chronic pelvic pain, dysmenorrhea or adenomyosis-associated cognitive dysfunction. Covers the ~1.5 million UK women living with endometriosis (~10% of women of reproductive age on Endometriosis UK / NHS England denominators), the 9 years 4 months UK average diagnostic delay (Endometriosis UK 2024 survey of 4,371 patients; 47% visited the GP 10+ times before diagnosis; 78% reported being dismissed), the November 2025 Lancet Obstetrics, Gynaecology & Women’s Health 'The overlooked symptom in endometriosis: brain fog' commentary by Mahony, Saunders, Whitaker and Horne at the University of Edinburgh EXPPECT centre, the April 2025 Horn / Sherman / Pehlivan Macquarie / Sydney Journal of Health Psychology FACT-Cog survey of 1,239 individuals reporting ~80% perceived cognitive impairment, the March 2025 NICE TA1057 approval of Ryeqo (relugolix-estradiol-norethisterone, Gedeon Richter) as the first daily oral combination GnRH-antagonist pill for long-term endometriosis symptom management on the NHS with ~1,000 women per year eligible, the April 2024 NICE NG73 endometriosis diagnosis and management update, the April 2026 renewed Women’s Health Strategy for England with 117 action points and explicit pledge to "eliminate the diagnostic odyssey", the 5 March 2026 Hansard Westminster Hall debate on Women’s Health Strategy: Endometriosis and Fibroids, the February 2026 Endometriosis UK 'State of Endometriosis Care' roadmap, the 2025 Frontiers in Immunology JAK-STAT / mast cell activation neuroinflammation paper, the 2023 Journal of Neuroinflammation Greaves group mouse-model CNS-wide glial activation paper showing microglial activation across thalamus, hippocampus and cortex, the Wu Hu Liang 2022 BMC Women’s Health paper documenting elevated BDNF and TrkB correlating with dysmenorrhea severity, the long-standing BDNF-elevated-in-peritoneal-fluid-and-plasma literature (Hu 2018; Wu 2014), the central-sensitisation hippocampal-amygdala-prefrontal-cortex network rewiring story, the ~3x migraine comorbidity, ~50% IBS overlap, ~25% fibromyalgia overlap, ~50% depression / anxiety burden, the ~80% adenomyosis co-existence, the BSGE-accredited endometriosis centres pathway, the ESHRE 2022 Becker / Bokor guideline, the RCOG framework, the Edinburgh EXPPECT (Andrew Horne, Philippa Saunders, Lucy Whitaker), Oxford CaRe (Krina Zondervan, Christian Becker) and Birmingham academic ecosystem, dienogest (Visanne), goserelin (Zoladex), leuprolide (Prostap), linzagolix (Yselty), elagolix (Orilissa), Mirena IUS, the central directionality risk that a synaptogenic HGF/c-Met peptide augmenting BDNF/TrkB-dependent plasticity could plausibly consolidate rather than weaken the very central-sensitisation pain-and-cognition pathology driving endometriosis brain fog, the additional HGF/c-Met ectopic lesion proliferation and angiogenesis concern, Endometriosis UK (helpline 0808 808 2227), The Endometriosis Foundation, the Pelvic Pain Support Network, the fosgonimeton (ATH-1017) Athira LIFT-AD Phase 3 failure and complete absence of any endometriosis testing, and the complete absence of any human Dihexa trial data in any endometriosis, adenomyosis, chronic pelvic pain or dysmenorrhea population.

Rigorous 2026 UK evidence review of whether a synaptogenic HGF/c-Met peptide like Dihexa has any role in systemic lupus erythematosus (SLE), lupus brain fog, neuropsychiatric SLE (NPSLE), lupus nephritis or cutaneous lupus populations. Covers the ~69,000-100,000 UK lupus population on the 2024 CPRD Yen / Singh analysis (point prevalence 21.4 per 100,000 in 1990 rising to 107.14 per 100,000 by 2020, incidence 5.47 per 100,000 person-years, 9:1 female:male ratio, higher prevalence and severity in British African / Caribbean and South Asian women); the Hanly pooled-prevalence meta-analysis showing 38% (95% CI 33-43%) measurable cognitive impairment and ~80% subjective brain fog; the 1999 ACR NPSLE case definition (19 syndromes: 12 central, 7 peripheral); the Diamond / DeGiorgio / Volpe 2001 Nature Medicine paper showing anti-dsDNA cross-reactivity with the NR2A/B NMDA-receptor pentapeptide D-W-E-Y-S; the Faust 2010 PNAS paper demonstrating BBB-permeability-dependent DNRAb-mediated hippocampal CA1 and lateral amygdala cognitive damage rescued by memantine; the 2021 Mougiakakos / Mackensen / Schett NEJM first CD19 CAR-T cell therapy refractory SLE patient and the 2022 Nature Medicine five-patient cohort with complete drug-free remission; the EULAR 2024 expanded 12-patient SLE / lupus nephritis cohort with 11 of 12 patients in drug-free remission at mean 458-day follow-up; the September 2025 Journal of Rheumatology preliminary quality-of-life and health-economic analysis of 8 patients followed >2 years; the 30 September 2024 CHMP positive recommendation and Q4 2024 EU approval of anifrolumab (Saphnelo, AstraZeneca) subcutaneous self-administration prefilled-pen formulation based on TULIP-SC; the November 2025 Bristol Myers Squibb late-breaking ACR Convergence Sotyktu (deucravacitinib) PAISLEY-SLE 4-year safety and efficacy integrated analysis with the POETYK SLE-1 (NCT05617677) and POETYK SLE-2 (NCT05620407) Phase 3 trials enrolling approximately 980 participants total for 60 weeks; the 2025 Biogen litifilimab (BIIB059) anti-BDCA2 plasmacytoid dendritic cell programme advancing to Phase 3 TOPAZ-1 SLE, TOPAZ-2 SLE and AMETHYST CLE; NICE TA882 voclosporin (Lupkynis) with mycophenolate mofetil for lupus nephritis (April 2023, AURORA-1 / AURORA-2); NICE TA397 belimumab IV (Benlysta, GSK, June 2016) and NICE TA752 belimumab SC (2021) anti-BAFF/BLyS axis; the terminated NICE TA793 anifrolumab UK appraisal due to no AstraZeneca evidence submission; the 2018 BSR systemic lupus erythematosus guideline (Gordon et al., Rheumatology) and 2024 BSR scope expansion to children, young people and adults; the 2019 EULAR/ACR weighted classification criteria (10-point system with ANA ≥1:80 entry); the SLE autoantibody landscape (anti-dsDNA, anti-Sm, anti-Ro/SSA, anti-La/SSB, anti-U1RNP, ribosomal-P [Bonfa 1987 NEJM lupus psychosis], antiphospholipid lupus anticoagulant / anti-cardiolipin / anti-beta-2-GPI driving secondary APS); the Watson 1983 PNAS lupus brain-reactive antibodies foundational paper; the type I interferon signature (IFN-alpha/beta) plasmacytoid dendritic cell pDC autoamplification loop; the BAFF / BLyS axis B-cell hyperactivity; the JAK/STAT/TYK2 signalling cascade; complement C3 / C4 hypocomplementaemia; the 2024 S100A8/A9 and MMP-9 cognitive-impairment biomarker paper (PMC10851148); the multiple commercial CD19 CAR-T programmes (Kyverna KYV-101 KYSA-1 / KYSA-3, Cabaletta CABA-201 RESET-SLE, Cartesian Descartes-08 BCMA mRNA, BMS bbT369 CD19/CD20 dual, AstraZeneca C-CAR168 RoseliCar CD19/BCMA dual); the conventional pharmacology (hydroxychloroquine cornerstone with Royal College of Ophthalmologists retinopathy screening, mycophenolate mofetil, azathioprine with TPMT/NUDT15 testing, methotrexate, low-dose Euro-Lupus pulse cyclophosphamide, rituximab off-label NHS England access protocol, prednisolone tapered to lowest effective dose); the SLE comorbidity cluster (fibromyalgia 22-25%, Sjogren's secondary 15-20%, antiphospholipid syndrome 30-40%, MCTD U1RNP, hEDS, depression 30-70%, anxiety, sleep disturbance, Long COVID); the conflicting BDNF-in-SLE serum literature (Petri 2021 Clinical Rheumatology 111-patient cohort decreased BDNF but no NPSLE cognitive correlation vs Eilat 2013 elevated BDNF/NGF); the Yamamoto 1996 elevated HGF in active SLE and the Niwa 1999 Nephrology Dialysis Transplantation elevated urinary HGF in lupus nephritis renal-protective compensation; the central directionality risk that a synaptogenic HGF/c-Met-activating peptide that augments NMDA-dependent synaptic plasticity could amplify rather than relieve the DNRAb-driven cognitive damage that memantine reverses; the c-Met oncogenicity / lymphoma background risk concern in SLE patients; the HGF/c-Met blood-brain-barrier and angiogenic protective biology (Wright & Harding 2015); the EG-501 NPSLE Phase 2 study (NCT07281105) and LUPUS Brain transcranial alternating current stimulation (tACS) NCT04141046; UK tertiary lupus services at UCLH Centre for Rheumatology, Louise Coote Lupus Unit (Guy's and St Thomas'), Manchester / Salford, Bath / Royal United Hospital, Birmingham, Edinburgh, Glasgow and Belfast; LUPUS UK (helpline 01708 731251, Romford), The Lupus Trust, Lupus Research Alliance, Versus Arthritis; the fosgonimeton (ATH-1017) Athira LIFT-AD Phase 3 failure and complete absence of any lupus testing; and the complete absence of any human Dihexa trial data in any systemic lupus erythematosus, cutaneous lupus, lupus nephritis or NPSLE population.

Rigorous 2026 UK evidence review of whether a synaptogenic HGF/c-Met peptide like Dihexa has any role in autism spectrum disorder (ASD), Asperger’s, PDD-NOS, Rett syndrome, Fragile X syndrome, Phelan-McDermid syndrome, Angelman syndrome, tuberous sclerosis or any neurodevelopmental population. Covers the ~700,000 UK autistic population (~1% prevalence) and the 2023 BJGP estimate of 150,000-500,000 adults aged 20-49 likely undiagnosed; the March 2026 NHS England Autism Statistics reporting 270,701 patients with an open referral and 89.7% breaching the NICE NG142 13-week standard; the 12 December 2025 FDA approval of DAYBUE STIX (trofinetide oral solution powder formulation, Acadia Pharmaceuticals / Neuren) for Rett syndrome aged 2+, building on the March 2023 LAVENDER Phase 3 approval; the 10 March 2026 FDA approval of leucovorin (folinic acid) only for cerebral folate deficiency in confirmed FOLR1 variant carriers and the explicit refusal to extend to broader autism following the January 2026 retraction of the Panda et al. European Journal of Pediatrics leucovorin-autism RCT; the 2026 NEJM Perspective on cerebral folate deficiency, autism and leucovorin; the January 2026 brain-wide [18F]FPEB PET study reporting 16-23% lower mGluR5 availability across cortical regions in autistic adults (left frontal pole -23%, left cingulate -23%, frontal lobe -19%, temporal lobe -19%, cerebellum -19%, fusiform gyrus -18%); the Carbonell-Roig & Aviles-Olmos 2026 Journal of Neural Transmission mGluR5 review; the Campbell 2006 PNAS family-based association of the rs1858830 MET promoter C-allele with autism in 204 families replicated in 539 families (combined p = 5×10−6) — the single most replicated functional autism candidate-gene variant and a direct mechanistic anchor to Dihexa’s HGF/c-Met pharmacology; the Campbell 2007 Annals of Neurology postmortem ASD cortex MET protein reduction; the Eagleson & Levitt 2015 Molecular Psychiatry MET-signalling forebrain glutamatergic circuit work; the Heuer 2011 Translational Psychiatry MET-maternal-autoantibody / cytokine interaction; the Volk 2014 Epidemiology MET-air-pollution gene-environment interaction; the Hedrick 2012 NeuroImage MET-cortical-thickness imaging genetics finding; the BDNF Val66Met (rs6265) polymorphism literature in autism (Hashimoto / Sakai 2016 meta-analysis) and the BDNF directionality paradox (Garcia-Penas, Connolly, Nelson 2003 Pediatrics showing elevated rather than depleted serum BDNF in autistic children and even newborns later diagnosed); NICE NG142 (September 2017, updated 2021) recognition / referral / diagnosis in under-19s, NICE NG87 (August 2013, updated 2021) management / support, NICE CG142 (June 2012, updated 2021) adult diagnosis and management, the UK Autism Act 2009 and Down Syndrome and Autism Act 2022, the National Autism Strategy 2021-2026, Building the Right Support, the NHS England national framework for all-age autism assessment pathways, the Right-to-Choose pathway via Psychiatry-UK / ProblemShared / Clinical Partners; the diagnostic ecosystem (M-CHAT-R/F, SCQ, AQ-10, ADOS-2, ADI-R, DISCO, 3Di); the National Autistic Society (NAS, 0808 800 4104), Autistica, Ambitious about Autism, Mencap, IPSEA, SFARI Gene database (1,000+ genes), SPARK (Simons Powering Autism Research, 100,000+ cohort) and MSSNG (Autism Speaks, 10,000+ genomes); the comorbidity landscape (ADHD 50-70%, anxiety 40-50%, depression 25-40%, OCD, epilepsy 20-30%, intellectual disability 30-50%, sleep disorders 50-80%, hEDS / hypermobility 22% Cederlof 2016, gender dysphoria 6-26% Warrier 2020); syndromic autism (Fragile X FMR1 ~1 in 4,000 males; Rett syndrome MECP2 ~1 in 10,000-15,000 girls; Angelman UBE3A 15q11-13; Phelan-McDermid SHANK3 22q13 ~1 in 8,000-15,000; tuberous sclerosis TSC1/TSC2 ~50% ASD; Down syndrome trisomy 21 16-19% ASD; CHARGE CHD7; Smith-Magenis RAI1; Williams 7q11.23 deletion ELN); the genetic architecture (Iossifov / Sanders 2014 Nature de novo, Grove / Børglum 2019 Nature Genetics polygenic, Tick / Bolton / Happé 2016 Mol Psychiatry 80-90% heritability); the autism drug-development graveyard (bumetanide SIGN1 / SIGN2 Servier 2021, balovaptan Roche V1A 2020, arbaclofen STX209 Seaside Therapeutics, mavoglurant AFQ056 / basimglurant Roche Fragile X 2014, intranasal oxytocin Sikich 2021 NEJM, CBD Aran 2021 Frontiers, NAC Hardan 2012, sulforaphane Singh-Talalay 2014 PNAS, FMT Kang 2017 / 2019); the central directionality risk that a synaptogenic HGF/c-Met-activating BDNF-elevating peptide given during sensitive-period plasticity could plausibly destabilise rather than rescue atypical cortical wiring (sensory hyper-responsivity reinforcement, RRB consolidation, anxiety amplification, E/I imbalance worsening); the HGF/c-Met synaptogenic mechanism of Dihexa (Benoist 2014 JPET; Wright & Harding 2015); fosgonimeton (ATH-1017) Athira LIFT-AD Phase 3 failure and the complete absence of any autism / Rett / Fragile X / neurodevelopmental testing; the safeguarding considerations under the Children Act 1989 / Working Together to Safeguard Children for the administration of unapproved peptides to children; and the complete absence of any human Dihexa trial data in any autism, ASD, Asperger’s, PDD-NOS, Rett syndrome, Fragile X syndrome or related neurodevelopmental population.

Rigorous 2026 UK evidence review of whether a synaptogenic HGF/c-Met peptide like Dihexa has any role in migraine, chronic migraine, hemiplegic migraine, vestibular migraine, medication-overuse headache or cluster-headache populations. Covers the ~10 million UK adults with migraine on Migraine Trust 2026 figures (~1 in 7 Britons, ~1 million chronic migraine, ~190,000 attacks per day, women three times more likely than men, 25-43 million lost workdays annually and a £6-10 billion economic cost), the 15 May 2024 NICE Technology Appraisal TA973 atogepant (Aquipta, AbbVie) 60mg once-daily oral CGRP-receptor antagonist approval reaching an estimated 170,000 England-eligible patients, NICE TA919 rimegepant acute and TA906 rimegepant prevention (Pfizer / Biohaven Vydura / Nurtec ODT), the CGRP monoclonal antibody pathway anchored by TA682 erenumab (Aimovig), TA659 galcanezumab (Emgality), TA764 fremanezumab (Ajovy) and TA871 eptinezumab (Vyepti), NICE TA260 onabotulinumtoxinA (Botox) for chronic migraine under the PREEMPT 31-site / 155-unit / 12-week protocol, the 2025 Fernandes & Gil-Gouveia Cephalalgia mechanistic review of migraine-related cognitive dysfunction, the 2025 Medical Research Archives chronic migraine accelerated brain ageing and hippocampal atrophy review, the 2024 Hippocampal Connectivity Dynamics resting-state fMRI volumetric paper (PMID 39675538), the 2022 P2X7R/NLRP3 pyroptosis and neuroinflammation migraine cognitive impairment mouse model (PMC9250730), the Tanure 2010 Headache pilot study finding serum BDNF elevated during migraine attacks (PMID 20556464), the cortical spreading depression (CSD) and trigeminovascular pathophysiology with CGRP, PACAP-38 and glutamatergic hyperexcitability biology, the BDNF Val66Met (rs6265) polymorphism in migraine susceptibility, NICE NG150 (September 2021) headache assessment in over-12s, the BASH British Association for the Study of Headache UK guideline, the Migraine Trust, National Migraine Centre, Brain Research UK, OUCH UK and Hemiplegic Migraine Association UK patient ecosystem, lasmiditan (Reyvow) 5HT1F ditan, zavegepant (Zavzpret) intranasal CGRP, ubrogepant (Ubrelvy), GammaCore nVNS, Cefaly external trigeminal neurostimulator and Nerivio remote electrical neuromodulation device pathways, the conventional preventative armamentarium (propranolol, amitriptyline, topiramate, candesartan, sodium valproate under the MHRA Pregnancy Prevention Programme), the migraine-with-aura ischaemic stroke risk axis, the patent foramen ovale (PFO) closure MIST / PRIMA / PREMIUM / CLOSURE-3 trial controversy, the CAMERA-1 and CAMERA-2 white-matter-hyperintensity studies, the medication-overuse headache (MOH) NICE NG150 management framework, vestibular migraine (Lempert / Society Barany 2012 criteria), hemiplegic migraine (CACNA1A, ATP1A2, SCN1A), cluster headache (oxygen, sumatriptan SC, verapamil, galcanezumab FDA 2019, GammaCore), the BDNF directionality paradox and CSD-threshold-lowering / central-sensitisation-consolidation risk for any synaptogenic peptide claim, the HGF/c-Met synaptogenic mechanism of Dihexa (Benoist 2014 JPET; Wright & Harding 2015), fosgonimeton (ATH-1017) Athira LIFT-AD Phase 3 failure and the complete absence of any human Dihexa trial data in any migraine population.

Rigorous 2026 UK evidence review of whether a synaptogenic HGF/c-Met peptide like Dihexa has any role in Myalgic Encephalomyelitis / Chronic Fatigue Syndrome (ME/CFS), post-exertional malaise (PEM), post-viral fatigue syndrome (PVFS), post-infectious ME/CFS, ME/CFS brain fog, Long COVID with ME/CFS overlap or any post-exertional symptom exacerbation (PESE) population. Covers the ~250,000 UK adult and paediatric ME/CFS population (75-85% women, ~25% severely or very severely affected on Action for ME / ME Association / 25% ME Group denominators); the 6 August 2025 DecodeME genome-wide association study preprint (Ponting, Edinburgh, MRC Human Genetics Unit, Action for ME) reporting eight genome-wide significant loci across 15,579 European-ancestry cases versus 259,909 controls with lead genes RABGAP1L, BTN2A2, OLFM4, FBXL4 and CA10 converging on viral defence, innate immunity and mitochondrial function with a striking female-only sex-specific signal (three of six primary loci replicated in females, none in males); the 22 July 2025 DHSC final UK ME/CFS Delivery Plan "My Full Reality" with the NIHR application development award scheme, MRC PRIME infrastructure programme and UKRI ME/CFS Priority Area; the 21 February 2024 NIH Walitt deep-phenotyping Nature Communications paper (PMC10881493) reframing post-infectious ME/CFS as a central rather than peripheral disorder with altered effort preference on the EEfRT task and central catechol dysregulation; the April 2025 ME Association £132,000 investment in the UBC double-blind low-dose naltrexone (LDN) trial led by Dr Luis Nacul in post-COVID fatigue syndrome with ME/CFS overlap (NCT05430152); the Nakatomi 2014 11C-(R)-PK11195 PET microglial activation finding in cingulate, hippocampus, thalamus, midbrain and pons; the August 2025 Younger UAB Birmingham MRI thermometry whole-brain neuroinflammation study; the Polli 2020 Arthritis & Rheumatology paper showing BDNF hypomethylation and elevated peripheral BDNF in CFS-with-fibromyalgia with symptom correlation; the October 2024 Maeve Boothby O'Neill Prevention of Future Deaths (Regulation 28) report and the absence of NHS England commissioned severe-ME inpatient provision; NICE NG206 (October 2021) removing graded exercise therapy and confirming post-exertional malaise as a required diagnostic feature; the Wong & Weitzer 2021 Medicina systematic review showing 25 of 29 ME/CFS symptoms in Long COVID populations, the Dehlia & Guthridge 2024 Journal of Infection meta-analysis estimating ~51% of Long COVID patients meet ME/CFS criteria, and the January 2025 RECOVER Vernon analysis showing 4.5% post-COVID ME/CFS prevalence (15x baseline); the Castro-Marrero 2021 coenzyme Q10 plus NADH RCT and 2024 mitochondrial review, the Cash & Kaufmann 2024 RESTORE-ME oxaloacetate RCT and REGAIN trial, the AIM ImmunoTech rintatolimod (Ampligen) AMP-518 Long COVID readout, the Berlin Cures BC 007 Phase 2 Long COVID failure November 2024, the David Systrom pyridostigmine (Mestinon) preload failure POTS programme, the low-dose aripiprazole observational case series; the ME/CFS comorbidity cluster (fibromyalgia, POTS, MCAS, hEDS, migraine, IBS, endometriosis, sleep apnea, depression, anxiety, MCI); the 85-90% cognitive dysfunction prevalence with information processing speed, working memory and sustained attention as dominant deficits; the central directionality risk that a synaptogenic peptide could plausibly consolidate rather than weaken pathologically over-driven sensorimotor and limbic post-exertional responses; the Polli BDNF directionality paradox; the HGF/c-Met synaptogenic mechanism of Dihexa (Benoist 2014 JPET; Wright & Harding 2015); the fosgonimeton (ATH-1017) Athira LIFT-AD Phase 3 failure and SHAPE PDD/DLB discontinuation as a cautionary clinical analogue; the UK NHS ME/CFS specialist clinic provision gap in Scotland, Wales (outside Betsi Cadwaladr UHB North Wales 2025) and Northern Ireland; Action for ME (0117 927 9551), ME Association ME Connect (0344 576 5326), Forward-ME, #ThereForME, 25% ME Group; and the complete absence of any human Dihexa trial data in any ME/CFS, post-viral fatigue or Long COVID population.

Rigorous 2026 UK evidence review of whether a synaptogenic HGF/c-Met peptide like Dihexa has any role in obstructive sleep apnea (OSA) brain fog, intermittent-hypoxia hippocampal damage, post-CPAP cognitive impairment, REM-sleep-specific CA1 hippocampal volume loss or any sleep-disordered breathing population. Covers ~13 million UK adults estimated to have OSA (~19.5% prevalence, 80-85% undiagnosed) on Sleep Apnoea Trust Association and Asthma + Lung UK denominators, the December 2024 FDA approval of Zepbound (tirzepatide) as the first ever prescription medicine for moderate-to-severe OSA with obesity on the back of SURMOUNT-OSA (NEJM, June 2024) showing 25-29 events/hour AHI reduction and 18-20% weight loss, the May 2025 University of California Irvine paper linking REM-sleep hypoxemia to CA1 hippocampal volume loss and memory impairment in older adults at risk for dementia (PMC11555004), the 2025 systematic review and meta-analysis across 23 studies and 33,226 patients estimating 36.92% pooled prevalence of cognitive impairment in OSA (PMC12537604), the 2025 PMC12022498 hippocampal-volume / T90 / SpO2 imaging study, the April 2025 Singh et al. Neurology paper on hypoxemia, white matter hyperintensities and temporal lobe changes, the Sunnybrook NCT06773416 CPAP cognition RCT (Feb 2025-Sep 2027), the CRESCENDO NCT06983769 CPAP vs MAD trial in cognitively impaired patients (Jan 2026-Dec 2030), the Brain Fog in Sleep Apnea trial (NCT06664450), NICE NG202 (August 2021) OSA/OHS in over-16s with the AHI 5-14.9 mild / 15-29.9 moderate / ≥30 severe grading, NICE IPG598 (2017) hypoglossal nerve stimulation with UCLH as a lead NHS Inspire centre, the Epworth Sleepiness Scale and STOP-BANG screening tools, home sleep apnoea testing and in-laboratory polysomnography, auto-CPAP and mandibular advancement devices (MAD), positional therapy, the OSA comorbidity cluster (resistant hypertension, atrial fibrillation, type 2 diabetes, stroke 3x risk, heart attack 4x risk, HFpEF, Long COVID, refractory migraine and morning headache, menopause, ADHD, depression, anxiety, erectile dysfunction), BDNF reduction under chronic intermittent hypoxia, beta-amyloid accumulation and glymphatic clearance, the HGF/c-Met synaptogenic and angiogenic mechanism of Dihexa (Benoist 2014 JPET; Wright & Harding 2015), fosgonimeton (ATH-1017) Athira LIFT-AD Phase 3 failure and SHAPE PDD/DLB discontinuation, modafinil / solriamfetol residual sleepiness context, the post-CPAP residual-cognitive-deficit population as the theoretical target group, the OSA-undiagnosed contribution to MCI, Long COVID brain fog and post-stroke cognitive impairment, and the complete absence of any human Dihexa trial data in any obstructive sleep apnea, central sleep apnea or chronic intermittent hypoxia population.

Rigorous 2026 UK evidence review of whether a synaptogenic HGF/c-Met peptide like Dihexa has any role in fibromyalgia (FM), fibromyalgia syndrome (FMS), fibro fog cognitive dysfunction, chronic widespread pain, nociplastic pain, central sensitisation syndromes, or the overlap conditions ME/CFS and Long COVID. Covers the ~2.8 million UK adult fibromyalgia population (~5.4% adult prevalence on Versus Arthritis / Fibromyalgia Action UK / Royal College of Physicians 2022 denominators); the 15 August 2025 FDA approval of Tonix Pharmaceuticals’ Tonmya (TNX-102 SL, sublingual cyclobenzaprine) as the first new FDA-approved fibromyalgia medication in 15 years (after pregabalin 2007, duloxetine 2008, milnacipran 2009), with Q4 2025 US commercial launch and the RELIEF and RESILIENT Phase 3 trials in nearly 1,000 patients hitting the 14-week pain endpoint and demonstrating reassuring safety; the ACR Convergence 2025 (November 2025) low-dose naltrexone (LDN) positive readouts and the May 2025 Annals of Medicine and Surgery systematic review and meta-analysis (PMC12055162) showing clinically meaningful pain and function gains with vivid dreams the principal reproducible adverse effect; the April 2025 ME Association funding of a 9-month University of British Columbia LDN trial in ME/CFS and Long COVID led by Dr Luis Nacul; the Dickson Chemist (Glasgow) UK LDN supply chain and the variable NHS Integrated Care Board access barrier; the 2024 Polli et al. PLOS One systematic review and meta-analysis identifying significantly elevated peripheral BDNF as a candidate fibromyalgia biomarker (the opposite direction from the BDNF deficit pattern in Alzheimer’s, depression and schizophrenia that underpins most BDNF-promoting nootropic claims) and the mechanistic implications for any synaptogenic peptide claim via NMDA potentiation, KCC2 downregulation and GABAergic disinhibition driving central sensitisation; the Albrecht et al. 2018/2019 multi-site [¹¹C]PBR28 PET Brain Behavior & Immunity study from the Loggia / Massachusetts General Hospital / Harvard Medical School group as the first in vivo human evidence of TSPO glial / microglial activation in thalamus, dorsolateral and medial prefrontal cortex, precuneus and anterior cingulate / insular cortex; the 2025 Exploration of Immunology and 2025 Cureus (PMC11853252) neuroinflammation reviews; the January 2026 Brain Sciences Montreal Cognitive Assessment case-control study consolidating >70% prevalence of measurable cognitive dysfunction and identifying pain severity, sleep quality, anxiety, depression and FIQR as independent predictors; the Royal College of Physicians 2022 first formal UK diagnostic guideline endorsing primary-care diagnosis using the ACR 2016 Widespread Pain Index + Symptom Severity Scale with 3-month chronicity; NICE NG193 (April 2021) chronic primary pain and the controversial recommendation against initiating paracetamol, NSAIDs, benzodiazepines, opioids and gabapentinoids (pregabalin, gabapentin) for chronic primary pain with only amitriptyline / citalopram / duloxetine / fluoxetine / paroxetine / sertraline permitted off-label; ICD-11 reframing as chronic primary musculoskeletal pain (MG30.01); the Moldofsky & Smythe 1975 alpha-EEG intrusion sleep architecture story and the bedtime-dosing rationale for Tonmya / amitriptyline / nortriptyline; the Oaklander 2013 Pain finding of intraepidermal nerve fibre density small fibre neuropathy in ~50% of fibromyalgia patients; central sensitisation / nociplastic pain framing (Clauw); the dense comorbidity cluster covering ME/CFS, Long COVID, IBS, migraine, TMD, restless legs syndrome, interstitial cystitis, endometriosis, hypermobile Ehlers-Danlos syndrome (hEDS), depression (60-80% lifetime), anxiety (50-70% lifetime), PTSD and adverse childhood experiences, mast cell activation syndrome; the off-label UK self-management ecosystem (CBD, medical cannabis, palmitoylethanolamide PEA, vitamin D, magnesium glycinate, CoQ10, melatonin, SAMe, 5-HTP, bacopa, ashwagandha, tDCS / rTMS); the HGF/c-Met synaptogenic mechanism of Dihexa (Benoist 2014 JPET PubMed 24403718; Wright & Harding 2015); the absence of any Russo HGF-deficiency series in fibromyalgia in contrast to the parallel papers in depression, anxiety, bipolar, autism and OCD; fosgonimeton (ATH-1017) and the absence of any pain-population testing in the Athira Pharma LIFT-AD / ACT-AD / SHAPE programmes; the central directionality risk that a synaptogenic BDNF-elevating HGF/c-Met-activating peptide could plausibly consolidate rather than weaken central sensitisation in a disorder where BDNF is already pathologically elevated (the fibromyalgia analogue of the central-gain risk in tinnitus, the CSTC-consolidation risk in OCD, the manic-switch risk in bipolar disorder and the prodromal-psychosis risk in schizophrenia); and the complete absence of any human Dihexa trial data in any fibromyalgia, chronic widespread pain or nociplastic pain population.

Rigorous 2026 UK evidence review of whether a synaptogenic HGF/c-Met peptide like Dihexa has any role in obsessive-compulsive disorder (OCD), body dysmorphic disorder (BDD), pure-O OCD, contamination OCD, harm OCD, relationship OCD (ROCD), scrupulosity, paediatric PANDAS / PANS, perinatal OCD, schizo-obsessive OCD, or any obsessive-compulsive spectrum condition. Covers the ~750,000 UK adult OCD population (1.2% point prevalence, 1-2% lifetime on Priory 2026 / OCD-UK figures), one of the WHO’s top-10 most disabling medical conditions worldwide; the 2013 Russo & Pietsch Biomarker Insights paper finding significantly decreased plasma hepatocyte growth factor (HGF), gamma-aminobutyric acid (GABA), urokinase plasminogen activator (uPA) and uPAR in OCD versus neurotypical controls (with low uPA / uPAR correlating with Y-BOCS symptom severity) — the single most direct biological link between Dihexa’s HGF/c-Met pharmacology and any psychiatric condition; the 2025 Gonzalez Journal of Neurochemistry review reframing OCD as an astrocyte disorder centred on Crym-positive striatal astrocytes gating perseverative behaviour through cortico-striatal presynaptic regulation; the 2025 Zhu Psychiatry & Clinical Neurosciences 1H-MRS meta-analysis consolidating decreased striatal NAA and elevated thalamic choline as the OCD neurometabolic signature; the 2025 Frontiers in Psychiatry static and dynamic striatal-subregion functional-connectivity paper mapping the ventromedial-vs-dorsolateral caudate abnormalities; the September 2025 Biohaven troriluzole (BHV-4157) Phase 3 PROUDD-1 / PROUDD-2 adjunctive-OCD-on-SSRI trial failures with no efficacy signal (NCT04693351 / NCT04641143 / NCT04708834); the Yale OCD Research Clinic (Pittenger group) randomised, double-blind, placebo-controlled, non-crossover single-dose psilocybin protocol and the parallel repeated-dosing study; Compass Pathways COMP360 25 mg synthetic psilocybin Phase 3 success in treatment-resistant depression (COMP005 2025 and COMP006 2026) with no Phase 3 OCD readout to date; the 2024 Mansueto Journal of Affective Disorders paper showing serum BDNF increases mediate cognitive recovery in OCD treatment responders; NICE CG31 (November 2005) with the confirmed autumn 2026 update consultation; the cortico-striato-thalamo-cortical (CSTC) circuit (orbitofrontal cortex, anterior cingulate, pre-SMA, ventromedial caudate, mediodorsal and ventral anterior thalamus); the BDNF Val66Met polymorphism; the SLC1A1 / GRIN2B / SLITRK5 / SAPAP3 genetic backbone; the GABAergic parvalbumin-interneuron deficit and its mechanistic alignment with HGF/c-Met biology; NHS Talking Therapies (formerly IAPT) ERP-based CBT pathway; high-dose SSRIs titrated to BNF maximum (fluoxetine, sertraline, fluvoxamine, paroxetine, escitalopram, citalopram), clomipramine, low-dose antipsychotic augmentation (risperidone, aripiprazole, quetiapine); the glutamate-modulator augmentation literature (N-acetylcysteine, memantine, riluzole, lamotrigine, topiramate, inositol, ondansetron, ketamine, CBD); FDA Humanitarian Device Exemption ventral-capsule / ventral-striatum DBS (Medtronic Reclaim, 2009) and the UK Cambridge bed nucleus of the stria terminalis (BNST) sham-controlled trial (2021); BrainsWay deep TMS H7 coil FDA approval (2018) and NICE IPG 709 (2021); bilateral anterior capsulotomy, anterior cingulotomy and MRgFUS focused ultrasound for the refractory tail; UK tertiary specialist services (South London & Maudsley Anxiety Disorders Residential Unit at Bethlem, Oxford Health OXTOP, Springfield Hospital London, Cambridge / Oxford / Bristol / Frenchay DBS centres); OCD-UK (Ashley Fulwood) and OCD Action and the International OCD Foundation (IOCDF); the OCD-depression comorbidity (60-65% lifetime), OCD-anxiety (30-50%), OCD-tic / Tourette / PANDAS-PANS overlap, OCD-bipolar (10-15%, manic-switch concern), OCD-schizophrenia (12-25% schizo-obsessive presentation, prodromal-psychosis concern); the OCD suicide-risk amplification (5-10× general population, 30% lifetime ideation, 10% lifetime attempt); the central directionality risk that augmenting BDNF/TrkB-dependent synaptic plasticity in a pathologically over-strengthened CSTC loop could plausibly consolidate rather than weaken the maladaptive learned compulsions; the ERP-augmentation reframe via extinction-learning consolidation (d-cycloserine analogue); the HGF/c-Met synaptogenic mechanism of Dihexa (Benoist 2014, JPET; Wright & Harding 2015); fosgonimeton (ATH-1017) and the absence of any anxiety / OCD spectrum testing in the Athira programme; and the complete absence of any human Dihexa trial data in any OCD or obsessive-compulsive spectrum population.

Rigorous 2026 UK evidence review of whether a synaptogenic HGF/c-Met peptide like Dihexa has any role in tinnitus, hyperacusis (loudness / annoyance / fear / pain subtypes), cochlear synaptopathy (‘hidden hearing loss’), somatic tinnitus, pulsatile tinnitus, sensorineural hearing loss, presbycusis, noise-induced hearing loss or any otologic indication. Covers the ~7.6 million UK adult tinnitus population on Tinnitus UK (British Tinnitus Association) and RNID figures with ~1.5 million severely affected, the February 2026 American Journal of Audiology peer-reviewed real-world evaluation of Lenire bimodal neuromodulation (Neuromod Devices, Dublin) reporting 81.8% clinically significant reduction in bothersome tinnitus after 12 weeks consolidating the March 2023 FDA De Novo authorisation backed by the TENT-A3 pivotal trial, the Susan Shore / University of Michigan / Auricle Inc signal-timing device 2023 JAMA Network Open randomised clinical trial in somatic tinnitus and the still-pending early-2026 FDA status, the July 2025 Frontiers in Neuroscience review by Lopes and colleagues consolidating BDNF as a central regulator of maladaptive auditory synaptic plasticity in tinnitus pathogenesis and treatment, the foundational Kujawa & Liberman 2009 Journal of Neuroscience cochlear synaptopathy paper showing noise exposure can destroy ~50% of inner-hair-cell ribbon synapses with no audiogram change in CBA/CaJ mice with permanent ABR wave I amplitude reduction, the 2025 Wang et al. Advanced Science noise-induced hidden hearing loss mechanism review, the 2022 Frontiers in Neuroscience meta-analysis of ABR-detected cochlear synaptopathy in tinnitus patients with normal hearing thresholds, NICE NG155 (March 2020) Tinnitus: assessment and management and its red-flag criteria (sudden sensorineural hearing loss within 72 hours, unilateral tinnitus, pulsatile tinnitus, focal neurology, severe distress with suicidal thinking), the British Society of Audiology high-frequency audiometry, the central-gain hypothesis of homeostatic plasticity in the dorsal cochlear nucleus, inferior colliculus and auditory cortex, the Jastreboff neurophysiological model of tinnitus distress, somatic tinnitus head-neck-jaw modulation, the Otonomy OTO-313 (intratympanic gacyclidine NMDA antagonist) Phase 2 failure in August 2022 and the Spiral Therapeutics OTIVIDEX / OTO-510 / OTO-413 (recombinant BDNF) asset acquisition, the Frequency Therapeutics FX-322 (Lgr5+ cochlear progenitor cells) hearing-loss-programme abandonment and Korro Bio merger, the Decibel Therapeutics / Regeneron DB-OTO AAV-based otoferlin gene therapy in OTOF-mutation paediatric hearing loss, the Audion BB103 (LY3056480, Notch inhibitor) Phase 1/2 progenitor-cell programme, the Hashir Tinnitus Clinic Annual Tinnitus Report 2026 covering 446 peer-reviewed studies, the NICE NG155-aligned NHS audiology pathway (CBT first-line for tinnitus distress, sound therapy, hearing aids, tinnitus retraining therapy), the UK private-pay Lenire route (~£2,500-3,500), NICE TA566 cochlear implants for severe-to-profound bilateral deafness, the HGF/c-Met synaptogenic mechanism (Benoist 2014, JPET) and the directionality concern that augmenting plasticity in an already-maladaptive auditory system could plausibly worsen rather than relieve the phantom percept, the fosgonimeton (ATH-1017) Alzheimer’s clinical analogue that has never been tested in any otologic indication, and the complete absence of any human Dihexa trial data in any tinnitus, hyperacusis, cochlear synaptopathy or hearing-loss population.

Rigorous 2026 UK evidence review of whether a synaptogenic HGF/c-Met peptide like Dihexa has any role in bipolar disorder, bipolar I, bipolar II, bipolar depression, mania, mixed affective episode, rapid cycling, schizoaffective disorder bipolar type or the residual bipolar cognitive impairment that persists into euthymia. Covers the ~1% UK adult prevalence (approximately 660,000 people) on Mental Health Foundation and NHS England Adult Psychiatric Morbidity Survey 2023-24 denominators, the 2025 NCISH National Confidential Inquiry report documenting 1,491 patient suicides with a primary bipolar diagnosis (8% of all patient suicides) and a 19% increase in 2019-2022 versus 2015-2018, the March 2025 UCL analysis of why bipolar suicide rates are so high, the Hayes et al. UK retrospective 5-year cohort of 2,649 people with bipolar disorder, the November 2025 FDA approval of Intra-Cellular Therapies / Johnson & Johnson Caplyta (lumateperone) as adjunctive major depressive disorder therapy on top of its existing US bipolar I and II depression indication as monotherapy and adjunct with lithium or valproate, the September 2025 UK MHRA reauthorisation of semi-sodium valproate for mania when lithium is not tolerated or contraindicated (subject to the Pregnancy Prevention Programme), the cariprazine (Vraylar/Reagila) paediatric Phase 4 programme enrolling ~380 patients aged 10-17 with bipolar I across ~60 sites worldwide and the cariprazine D3-imaging Phase 4 mechanistic study, lithium as gold-standard neuroprotective psychotropic (Hajek 2012 hippocampal-volume meta-analysis showing the bipolar deficit is masked by lithium exposure, Yucel 2007 longitudinal bilateral hippocampal volume increases on long-term lithium, Kakhki 2016 voxel-based morphometry in elderly bipolar patients with verbal memory gains over 4 years, the 2025 lithium-neuroprotection cytoskeletal-proteomic translational mechanism review consolidating the GSK-3β-inhibition / BDNF-upregulation / tau-dephosphorylation / amyloid-β42-reduction case), the often-overlooked Russo 2010 finding that serum hepatocyte growth factor (HGF) is decreased in bipolar disorder and normalises with zinc and antioxidant therapy as the single most direct biological link between Dihexa’s HGF/c-Met mechanism and bipolar pathology, the Grande 2010 BDNF-as-mediator-of-neuroplasticity case, the 2021 Cambridge BJPsych Open BDNF study in newly-diagnosed patients and unaffected first-degree relatives, ketamine and esketamine in bipolar depression (Salloum 2024 real-world cohort of 38 patients with 39% response and 13% remission and no manic switch; the 2025 retrospective cohort of 2,126 patients on esketamine showing significantly lower suicide outcomes at 1-7 days through 1 year; the 2024 IV ketamine bipolar systematic review and meta-analysis), AXS-05 (dextromethorphan-bupropion / Auvelity) BDNF/TrkB engagement, the KarXT Cobenfy bipolar I mania Phase 4 commitment, NICE CG185 standard of care, the theoretical manic-switch risk of any synaptogenic intervention, NHS shared-care lithium prescribing and monitoring, Bipolar UK, Mind, Rethink Mental Illness, the Samaritans crisis helpline 116 123 and the complete absence of any human Dihexa trial data in any bipolar disorder population.

Rigorous 2026 UK evidence review of whether a synaptogenic HGF/c-Met peptide like Dihexa has any role in chronic traumatic encephalopathy (CTE), traumatic encephalopathy syndrome (TES), or the long-term consequences of repetitive head impact (RHI) exposure. Covers the January 2026 Boston University CTE Center 614-brain-donor study in Alzheimer’s & Dementia establishing CTE as a distinct cause of dementia (~4× odds at high stage, comparable to advanced Alzheimer’s pathology); the May 2026 Boston University paper showing the proposed clinical TES criteria identify only 24% of autopsy-confirmed CTE cases with serious misdiagnosis concerns in athletes and veterans; the active UK group action by more than 1,100 former rugby union and rugby league players (including 2003 England World Cup-winning squad members Steve Thompson, Mark Regan and Phil Vickery, and Welsh internationals Gavin Henson, Colin Charvis and Ryan Jones) against World Rugby, the RFU, the WRU and the RFL, next scheduled for review in March 2026; the 2023 Glasgow / Sydney / Boston rugby brain-bank study (~68% CTE in 31 donors, with risk increasing with career length); the 2017 Boston University NFL paper (CTE in 99% of 111 examined NFL players); the four CTE pathology axes (perivascular hyperphosphorylated p-tau at sulcal depths, blood-brain barrier leakage, chronic microglial activation, synaptic loss), the McKee 2023 neuropathological staging I-IV, the sub-concussive head impact biology, dynamic contrast-enhanced MRI of BBB leakage as a 2026 early-warning imaging biomarker, plasma neurofilament light chain (NfL) and p-tau-181 / p-tau-217 / p-tau-231 blood biomarkers, the 2025 bioRxiv spatially resolved transcriptomics CTE signature, the UCSF Brain Injury Clinical Trials 2026 programme, the early-phase mood-behavioural CTE phenotype (depression, impulsivity, suicidality) versus the late-phase progressive cognitive phenotype, the FIELD Scottish footballer mortality study and FA under-12s heading limits, dementia pugilistica and boxing CTE, soccer heading, ice hockey, MMA, and military blast RHI cohorts, the World Rugby / Drake Foundation / University of South Wales elite player Brain Health Service, the Imperial College London Sport Concussion Service, the NHS Op COURAGE veterans pathway, NICE NG97 dementia diagnostic pathway, the 2024 Lancet Commission 14 modifiable dementia risk factors covering 45% of cases, the HGF/c-Met synaptogenic mechanism mapped onto each CTE pathology axis (very weak case for tau, plausible for BBB sealing, plausible for microglial repolarisation, plausible for synaptogenesis), the fosgonimeton (ATH-1017) LIFT-AD / ACT-AD / SHAPE clinical analogue, and the complete absence of any human Dihexa trial data in any CTE, TES, suspected-CTE, former contact-sport athlete, or military blast-exposure population.

Rigorous 2026 UK evidence review of whether GLP-1 receptor agonists (semaglutide / Ozempic / Wegovy / Rybelsus, tirzepatide / Mounjaro / Zepbound, liraglutide, exenatide, dulaglutide) protect or harm the brain, where a synaptogenic HGF/c-Met peptide like Dihexa converges on the same downstream BDNF / synaptic-plasticity axis, and where the NHS Mounjaro rollout actually stands in 2026. Covers the November 2025 Novo Nordisk EVOKE / EVOKE+ Phase 3 trials of oral semaglutide (Rybelsus) versus placebo in 3,808 adults with early symptomatic Alzheimer’s disease (no CDR-SB or secondary cognitive/functional benefit at 104 weeks despite ~10% reductions in neuroinflammation and AD-related biomarkers; 1-year extension discontinued), the AD/PD 2026 full readout, the 2025 JAMA Network Open cohort (n>60,000 with T2DM and obesity, HR 0.63 for incident dementia with semaglutide or tirzepatide vs other antidiabetics), the US Department of Veterans Affairs ~200,000 patient cohort (lower neurocognitive-disorder incidence), the 2024 target-trial emulation across 1,710,995 patients (40-70% lower 3-year AD-related dementia incidence on semaglutide vs insulin), the Daly et al. 2025 Alzheimer’s & Dementia case for APOE4-homozygote prevention trials, the GLP-1R / cAMP / PKA / CREB / BDNF mechanism plus AMPK, anti-neuroinflammatory microglial polarisation and the ‘type 3 diabetes’ brain-insulin-resistance hypothesis, the ‘Ozempic brain fog’ phenomenology and its mundane mechanisms (hypoglycaemia, dehydration, protein/B-vitamin/micronutrient gaps from rapid caloric restriction, metabolic transition), the NHS England weight-management-injection rollout milestones (23 March 2025 specialist services, 23 June 2025 primary-care expansion, 1 April 2026 QOF GP-contract integration under NICE TA1026, targeting 220,000 patients in three years), the BMI 40 / BMI 35 with comorbidity eligibility and the 2.5 kg/m² reduction for South Asian, Chinese, other Asian, Middle Eastern, Black African and African-Caribbean populations, NICE TA875 Wegovy in specialist weight management, the SELECT cardiovascular outcomes trial (20% MACE reduction in obesity without diabetes), FLOW (kidney outcomes in T2DM with CKD), STEP-HFpEF (heart failure with preserved ejection fraction in obesity), SURMOUNT-OSA (tirzepatide FDA approval for OSA in obesity December 2024), the exenatide-PD2 (Athauda 2017 Lancet) positive Parkinson’s signal and the Cleveland Clinic NLY01 Phase 2 negative read, the NIHR Oxford Health BRC 2025 study finding semaglutide safe for brain health with possible benefits for cognition and nicotine dependence, the EMA suicidal-ideation review and the semaglutide NAION optic-neuropathy signal, the retatrutide / orforglipron / CagriSema next-generation incretin pipeline, the convergence of the GLP-1R cAMP/PKA/BDNF axis with the HGF/c-Met MAPK/PI3K/BDNF axis downstream, and the complete absence of any human Dihexa trial data in any GLP-1 RA-treated population.

Rigorous 2026 UK evidence review of whether a synaptogenic HGF/c-Met peptide could help schizophrenia, schizoaffective disorder, first-episode psychosis, treatment-resistant schizophrenia, cognitive impairment associated with schizophrenia (CIAS), negative symptoms or prodromal CHR-P / UHR psychosis. Covers the ~220,000-strong UK schizophrenia patient base on the Royal College of Psychiatrists National Audit of Psychosis denominator, the April 2026 OHID / NHS England severe-mental-illness prevalence model (0.31-0.43% across English regions, highest in London), the September 2024 FDA approval of Bristol Myers Squibb’s KarXT / Cobenfy (xanomeline-trospium) as the first non-D2 schizophrenia mechanism in ~30 years and the 2026 UK MHRA submission and launch plan at ~$22,500 annual list price, the ARISE adjunctive Phase 3 negative read, the January 2025 Boehringer Ingelheim iclepertin (BI 425809) CONNEX Phase 3 failure across 1,840 patients in 41 countries with CONNEX-X discontinuation, the AbbVie / Cerevel emraclidine EMPOWER-1 and EMPOWER-2 Phase 2 failures, the ulotaront DIAMOND Phase 3 failure, the Sekar et al. Nature 2016 C4 complement synaptic-pruning hypothesis and the 2025 Frontiers in Synaptic Neuroscience extension, BDNF Val66Met negative-symptom association, the MET schizophrenia GWAS Caucasian signal and the CommonMind Consortium HGF mRNA upregulation, the HGF/c-Met GABAergic interneuron biology, NICE CG178, NG191 antipsychotic monitoring, clozapine for treatment resistance, the NHS England EIP two-week waiting-time standard, OASIS Maudsley CHR-P prodromal service, CIRCuiTS cognitive remediation, Rethink Mental Illness, Mind, the Hearing Voices Network and the complete absence of any human Dihexa trial data in any psychotic disorder.

Rigorous 2026 UK evidence review of whether a synaptogenic HGF/c-Met peptide could help Huntington’s disease (HD), juvenile HD (JHD), late-onset HD, pre-manifest gene-positive carriers or any HD subpopulation. Covers the ~7,000 UK HD patients under Huntington’s Disease Association (HDA) care and the 1-in-10,000 community prevalence, the September 2025 uniQure AMT-130 AAV gene-therapy ~75% slowing of disease progression on cUHDRS at 36 months announced jointly with UCL/UCLH and the Cardiff Advanced Neurotherapies Centre (ANTC) as the only UK surgical site, the November 2025 break with the FDA, the 2 March 2026 FDA Type-A meeting requiring a prospective, randomised, double-blind, sham-surgery-controlled Phase 3 before any BLA, the Wave Life Sciences WVE-003 SELECT-HD Phase 1b/2a first clinical demonstration of allele-selective mutant huntingtin lowering (46% mean CSF mHTT reduction at 30 mg) with preservation of wild-type huntingtin and a caudate atrophy correlation, the PTC Therapeutics PTC518 / votoplam PIVOT-HD 24-month interim extension reporting 52% slowing of cUHDRS at 10 mg in Stage 2 HD versus a propensity-weighted natural-history cohort, the Novartis-led global INVEST-HD Phase 3 launch under the 2024 PTC-Novartis licensing deal, the Roche tominersen GENERATION HD1 failure and ongoing GENERATION HD2, the Novartis branaplam VIBRANT-HD termination, the SAGE-718 (dalzanemdor) SURVEYOR-HD failure, the CAG-trinucleotide-repeat HTT expansion biology, the somatic-instability axis (MSH3, FAN1, PMS1, LIG1), the BDNF deficiency in HD striatum and the corticostriatal BDNF/TrkB axis driving medium spiny neuron loss, the HGF/c-Met synaptogenic case, NHS NICE tetrabenazine and the deutetrabenazine / valbenazine VMAT2 family for chorea, the UCL Huntington’s Disease Centre, Cardiff University Huntington’s Disease Centre, the HDA Specialist Advisor service, Scottish Huntington’s Association, Brain Research UK, ENROLL-HD and HDClarity, CHDI Foundation, HDBuzz, the UK predictive genetic testing pathway, Mental Capacity Act 2005 considerations, juvenile and late-onset HD, and the complete absence of any human Dihexa trial in any HD population.

Rigorous 2026 UK evidence review of whether a synaptogenic HGF/c-Met peptide could help dementia with Lewy bodies (DLB), Parkinson’s disease dementia (PDD), mild cognitive impairment with Lewy bodies (MCI-LB), prodromal DLB or REM sleep behaviour disorder. Covers the ~100,000-strong UK DLB patient base (10-15% of all UK dementia, 3rd most common), the December 2025 CervoMed RewinD-LB extension-phase positive results for the oral p38α MAP kinase inhibitor neflamapimod, the April 2026 AAN Chicago first-ever placebo-controlled MRI evidence that neflamapimod increased basal forebrain volume and functional connectivity in DLB, the FDA alignment on a 300-patient registration-enabling Phase 3 starting H2 2026, the Norwegian ANeED Phase IIa ambroxol trial targeting GBA1 glucocerebrosidase biology, the AD/PD 2026 analysis showing strongest effects in DLB without AD co-pathology, the maturation of alpha-synuclein seed-amplification assays (aSyn-SAA / RT-QuIC) at ~87% CSF accuracy, the 2024 Movement Disorder Society biomarker-based research criteria for prodromal DLB and MCI-LB, the Lancet Neurology 2025 evolving DLB therapeutic landscape review, NICE NG97 recommendations on rivastigmine and donepezil, the severe neuroleptic / antipsychotic sensitivity profile, the Robin Williams / Susan Schneider Williams advocacy legacy, the LBDA 2026 Annual Meeting, Parkinson’s UK, the Newcastle Lewy Body Lab, GBA1/SNCA/APOE/LRRK2 genetic backbone, the basal-forebrain cholinergic biology that maps onto HGF/c-Met synaptogenic signalling, the DLB vs PDD one-year rule, the fosgonimeton SHAPE PDD signal, the prasinezumab PADOVA and minzasolmin ORCHESTRA adjacent programmes, and the complete absence of any human Dihexa trial data in any Lewy body population.

Rigorous 2026 UK evidence review of whether a synaptogenic, angiogenic, BBB-sealing HGF/c-Met peptide could help vascular dementia (VaD), vascular cognitive impairment (VCI), subcortical ischaemic vascular dementia, multi-infarct dementia, post-stroke dementia, mixed Alzheimer-vascular dementia, cerebral small vessel disease, CADASIL or related conditions. Covers the ~150,000 UK VaD patient base (17% of all UK dementia, 2nd most common), the April 2026 UCLA Health vascular-cell-brain-cell inflammation mechanism and brain-repair breakthrough with a repurposed psoriasis drug, the April 2026 UNSW Sydney CHeBA Mendelian-randomization study nominating APOE, TOMM40, ERAP and SAA1-4 as causal targets, the University of Manchester Kir2.1 / amlodipine cerebral microcirculation rescue, the 2026 World Stroke Organization Vascular Dementia Fact Sheet, the 2024 Lancet Commission's 14 modifiable risk factors covering 45% of dementia, NICE NG97 guidance, the MarkVCID consortium biomarker frame, CY6463 and NAC trials, the 2025 Science Advances CADASIL phosphodiesterase-5 rescue paper, mixed Alzheimer-vascular pathology and the HGF/c-Met angiogenesis / BBB-sealing / synaptogenic biology that fits VaD more cleanly than any other indication on this site — with the complete absence of any human Dihexa trial in any vascular cognitive population.

Rigorous 2026 UK evidence review of whether a synaptogenic HGF/c-Met peptide could help frontotemporal dementia (FTD), behavioural variant FTD (bvFTD), primary progressive aphasia (PPA), FTD-GRN, FTD-MAPT, FTD-C9orf72 or the ALS-FTD spectrum. Covers the 31,000-strong UK FTD patient base with an 80% NHS diagnosis gap (~3,000 formally diagnosed), the 21 October 2025 Alector latozinemab (AL001) Phase 3 INFRONT-3 failure in FTD-GRN despite 2-fold sustained plasma progranulin elevation, the 49% Alector workforce reduction, the April 2026 Denali / Takeda termination of the DNL593 (PTV:PGRN) collaboration with Denali regaining full rights, the Vesper Bio VES001 oral sortilin modulator SORT-IN-2 readout expected H2 2026 in asymptomatic GRN carriers, the Passage Bio PBFT02 AAV-PGRN gene therapy upliFT-D programme, the Wave Life Sciences WVE-004 FOCUS-C9 discontinuation in C9orf72-ALS/FTD, FTLD-tau vs FTLD-TDP molecular pathology, MAPT / GRN / C9orf72 monogenic causes, microglial dysfunction and complement-mediated synaptic pruning, the AFTD Hope Rising 2026 Benefit ($2.1M; Emma & Bruce Willis honoured with the Susan Newhouse Award; launch of the Emma & Bruce Willis Fund for Dementia Research), Cambridge Centre for Frontotemporal Dementia, UCL Rare Dementia Support, Alzheimer's Research UK, Dementia UK Admiral Nurse Helpline, NICE NG97, the SSRI off-label evidence base for behavioural symptoms, the GENFI international research network, and the complete absence of any human Dihexa trial data in any FTD subtype.

Rigorous 2026 UK evidence review of whether a synaptogenic HGF/c-Met peptide could help post-traumatic stress disorder, complex PTSD (ICD-11 CPTSD), acute stress disorder, treatment-resistant PTSD or moral injury. Covers the amygdala-vmPFC fear-extinction model, the 2010 Peters et al. Science paper showing infralimbic BDNF infusion is sufficient for fear extinction in extinction-failure animals, the BDNF / H3K9me2 epigenetic literature, the angiotensin IV / HGF/c-Met convergence onto BDNF downstream plasticity machinery, NICE NG116 first-line trauma-focused CBT and EMDR pathway, the MAPS / Lykos MHRA Innovation Passport for MDMA-assisted therapy, the August 2024 FDA Complete Response Letter on Lykos MDMA, ketamine and esketamine in PTSD, the 2025 stellate ganglion block systematic review and meta-analysis, NHS Op COURAGE for veterans and the 2024 Murthy et al. evaluation, KCMHR longitudinal data (7.4% overall, 17% combat-deployed), the 2025 CPTSD prevalence meta-analysis, Combat Stress, Forces in Mind Trust, and the complete absence of any human Dihexa trial data in PTSD.