{"id":"dihexa","name":"Dihexa","aliases":["PNB-0408","N-hexanoic-Tyr-Ile-(6) aminohexanoic amide","angiotensin IV analogue"],"url":"https://lyoresearch.com/compounds/dihexa","class":{"id":"nootropic-peptides","name":"Nootropic and sleep peptides","url":"https://lyoresearch.com/classes/nootropic-peptides"},"summary":"Dihexa is a small synthetic molecule derived from angiotensin IV, studied for its striking ability to promote new synapse formation in rodents and its potential in memory and Parkinson's models. It is not a true peptide and, more importantly, has never been tested in a controlled human trial. It is sold as a 'nootropic' research chemical with no human evidence and no safety data.","overall_grade":"D","overall_grade_meaning":"no human evidence","human_trials":"0 controlled","regulatory_status":"Not approved","molecule":{"formula":"C27H44N4O5","molecular_weight":"504.7","cas":"1401708-83-5","pubchem_cid":129010512,"note":null},"pharmacokinetics":{"basis":"none","route":"Oral or topical as sold; no human study","half_life":"No human pharmacokinetic data","licensed_regimen":null,"product":null,"source":null},"outcomes":[{"outcome":"Cognition / synapse formation","grade":"D","grade_meaning":"no human evidence","effect_size":"not measurable","adverse":false,"human_studies":"0 controlled","evidence":"Dihexa promotes synaptogenesis and improves memory in rodent models, including models of Alzheimer's and Parkinson's disease. No human trial has tested it.","references":[]},{"outcome":"Safety in humans","grade":"D","grade_meaning":"no human evidence","effect_size":"not measurable","adverse":true,"human_studies":"None","evidence":"No human dosing study exists. A molecule that drives new synapse formation this potently has an obvious theoretical concern — uncontrolled growth signalling — that has never been evaluated in people.","references":[]}],"regions":[{"region":"European Union","status":"Unauthorised medicinal product","note":"No marketing authorisation in any member state. Supplying it for human use is an offence under national medicines law; a 'research use only' label does not change that."},{"region":"United States","status":"Not approved","note":"Not an approved drug and not a dietary-supplement ingredient. Sold as a 'research chemical' outside the medical system; the FDA has warned against several compounds in this class."},{"region":"United Kingdom","status":"Unlicensed medicine","note":"Not licensed by the MHRA. Selling or supplying it for human use is an offence under the Human Medicines Regulations 2012."},{"region":"Australia","status":"Prescription-only / unapproved","note":"Not on the ARTG. Supply without a prescription is unlawful; imports are seized."},{"region":"Canada","status":"Not authorised","note":"No Drug Identification Number; selling it for human use is illegal."},{"region":"Sport (WADA)","status":"Prohibited at all times","note":"As a non-approved substance, dihexa falls under WADA class S0 (non-approved substances) and is prohibited in and out of competition."}],"faq":[{"q":"Does dihexa improve memory in people?","a":"Unknown. The memory and synapse data are entirely from rodents. There is no controlled human trial."},{"q":"Is dihexa safe?","a":"There is no human safety data at all. Its mechanism — potently driving new synapse and growth signalling — is a theoretical concern that has never been evaluated in people."}],"references":[{"cite":"McCoy AT, et al. Evaluation of metabolically stabilized angiotensin IV analogs as pro-cognitive/anti-dementia agents (dihexa).","where":"J Pharmacol Exp Ther, 2013;344:141–154","url":"https://pubmed.ncbi.nlm.nih.gov/?term=McCoy+dihexa+angiotensin+IV+cognitive+2013","note":"The rodent synaptogenesis work."}],"last_reviewed":"2026-09-03","literature_searched_to":"2026-09-03","changelog":[{"date":"2026-09-03","note":"Initial publication. Grade D on absence of any human trial."}],"license":"CC BY 4.0 — cite as “LYO Research” with a link.","methodology":"https://lyoresearch.com/methodology"}