Compare prices and buy Dihexa from 14 research peptide vendors - also called suppliers or sources. Updated daily.
Dihexa (PNB-0408, ATH-1001, N-hexanoic-Tyr-Ile-(6)-aminohexanoic amide, C27H44N4O5, CAS 1401708-83-5) is a peptidomimetic derived from the hexapeptide angiotensin IV, developed at Washington State University and reported by its developers as orally active in rats. It is proposed to stimulate synapse formation by potentiating hepatocyte growth factor (HGF) signaling at the c-Met receptor, but the journal retracted the paper that established that mechanism after a university investigation found falsified or fabricated data. No clinical trial has given dihexa itself, only its injectable phosphate prodrug fosgonimeton, and dihexa is not FDA-approved.
For research purposes only. Not medical advice.
Dihexa is a synthetic analog of angiotensin IV, the hexapeptide Val-Tyr-Ile-His-Pro-Phe, designed at Washington State University (McCoy, Journal of Pharmacology and Experimental Therapeutics, 2013). It keeps only the parent's tyrosine and isoleucine, capped with hexanoic acid at one end and 6-aminohexanoic amide at the other. Two standard amino acids joined by a peptide bond, flanked by a fatty-acid cap and a non-standard amino acid, make it a peptidomimetic, and FDA's substance registry files it as a chemical with the formula C27H44N4O5.
That registry lists CAS 1401708-83-5 and the development codes PNB-0408 and ATH-1001. FDA's compounding lists name the acetate salt, dihexa acetate. It is catalogued with the nootropic and neurological compounds because of how it is marketed.
The 2013 paper reported that dihexa reversed memory deficits in scopolamine-treated and aged rats and called it "orally active". A 2014 paper from the same group proposed its mechanism: dihexa binds hepatocyte growth factor (HGF) and amplifies signaling through its receptor, c-Met, driving new synapse formation (Benoist, same journal, 2014).
In September 2021 the journal attached expressions of concern to both papers and to a 2012 paper on related analogs. In April 2025 it retracted the 2014 and 2012 papers, along with a 2011 paper from the group. The 2014 notice says a Washington State University investigation found falsified or fabricated data in three figure panels and in a later erratum submission, and found two of the authors solely responsible. The 2013 paper still carries its expression of concern and had not been retracted as of October 2026.
The primary evidence for the HGF and c-Met mechanism has therefore been retracted. The dihexa findings described here all come from cells and rodents.
Athira Pharma, the exclusive licensee of Washington State University's dihexa patents, took a closely related molecule into people. Fosgonimeton (ATH-1017, earlier NDX-1017) is dihexa with a phosphate group on its tyrosine, and their PubChem formulas differ by exactly one HPO3. Athira's Phase 1 trial report (Journal of Alzheimer's Disease, 2022) describes it as a prodrug injected under the skin and "rapidly converted into the active metabolite ATH-1001 in plasma", and FDA's registry records dihexa as that active metabolite.
Athira paused fosgonimeton after LIFT-AD to focus on a successor compound, ATH-1105, and renamed itself LeonaBio in January 2026. None of the trials gave dihexa itself.
Dihexa has no FDA approval, and drugsfda returns no match for dihexa or fosgonimeton as of October 2026. ClinicalTrials.gov holds no registration naming dihexa or PNB-0408.
FDA placed dihexa acetate in Category 2 under section 503A, its list of bulk substances that may present significant safety risks, on September 29, 2023. Its entry says FDA identified no human exposure data on products containing dihexa acetate by any route and lacks information on whether it would harm people. On April 15, 2026 FDA announced the removal of twelve withdrawn nominations from Category 2, effective seven days later. Dihexa acetate now sits in the page's withdrawn-nominations table with that text unchanged, and the removal permits nothing by itself.
FDA has also named dihexa acetate as one of five substances for a Pharmacy Compounding Advisory Committee meeting to be held before the end of February 2027, on whether to add it to the 503A bulks list. It was not on the July 23-24, 2026 agenda.
Only partly. Dihexa is a peptidomimetic derived from angiotensin IV, the hexapeptide Val-Tyr-Ile-His-Pro-Phe. It keeps the parent's tyrosine and isoleucine, joined by a peptide bond, and replaces the rest with a hexanoic acid cap at one end and 6-aminohexanoic amide at the other. FDA's substance registry files it as a chemical with the formula C27H44N4O5 and CAS 1401708-83-5, and lists the codes PNB-0408 and ATH-1001. According to the 2013 Washington State University paper that introduced it, the modifications were meant to resist enzymatic breakdown and to cross the gut and blood-brain barriers, which unmodified angiotensin IV peptides do poorly.
The paper behind its proposed mechanism has. In April 2025 the Journal of Pharmacology and Experimental Therapeutics retracted a 2014 paper proposing that dihexa works by amplifying hepatocyte growth factor signaling at the c-Met receptor, along with 2011 and 2012 papers on related analogs from the same group. The 2014 retraction notice cites a Washington State University investigation that found falsified or fabricated data. The 2013 paper that first described dihexa and its activity in rats has carried an expression of concern since September 2021 and had not been retracted as of October 2026. ClinicalTrials.gov lists no trial of dihexa itself.
Fosgonimeton, also called ATH-1017, is dihexa with a phosphate group attached to its tyrosine. Its developer, Athira Pharma, described it as a prodrug given by injection under the skin that is rapidly converted in plasma to dihexa, and FDA's substance registry lists dihexa as its active metabolite. It is the only form of the molecule in registered human trials. The Phase 2 ACT-AD trial and the Phase 2/3 LIFT-AD trial in mild to moderate Alzheimer's disease both missed their primary endpoints at 26 weeks, and Athira paused development of fosgonimeton in 2024. The company renamed itself LeonaBio in January 2026.
Dihexa acetate was in Category 2 under section 503A, FDA's list of bulk substances that may present significant safety risks, from September 29, 2023. FDA said it had identified no human exposure data by any route and lacked information on whether it would cause harm. On April 15, 2026 FDA announced the removal of twelve withdrawn nominations from Category 2, effective seven days later, and dihexa acetate moved to the withdrawn-nominations table with that safety text kept. The removal permits nothing on its own. FDA has named dihexa acetate for a Pharmacy Compounding Advisory Committee meeting to be held before the end of February 2027. Dihexa has no FDA approval.
PeptideScouter computes a price per milligram only for vials whose contents are stated in milligrams. Capsules are sold by count, so capsule listings are indexed but carry no per-milligram figure and are left out of every per-milligram median and comparison on the site. A capsule figure would also be hard to compare for a second reason: FDA's compounding lists name the acetate salt, dihexa acetate, and product titles do not say whether a stated milligram strength counts the salt or the free compound.
Dihexa is sold by 14 research peptide vendors indexed on PeptideScouter, with 19 tracked listings compared per vendor in the table above. Pricing is normalized and refreshed daily.
11 of the 14 indexed vendors currently have Dihexa in stock. The comparison table marks out-of-stock listings, and stock state is refreshed daily.
Biotech Compounds currently lists Dihexa at $5.40/mg, the lowest listed price across 14 tracked research peptide vendors. With current vendor discount codes applied, the lowest effective price is $1.71/mg.
Discount codes are issued per vendor rather than per peptide, so any code applies across that vendor's whole catalog. All 14 vendors listing Dihexa publish a PeptideScouter code, worth 5% to 20% off. Applied, the lowest effective price falls from $1.90/mg listed to $1.71/mg at Studz Peptides. Each vendor's code is shown beside its price in the table above.
Dihexa ranges from $1.90/mg to $7.16/mg across 19 listings from 14 research peptide vendors, normalized to USD per milligram and refreshed daily.
14 research peptide vendors currently list Dihexa on PeptideScouter, with 11 in stock right now. We track 19 listings across size and kit variants.
Dihexa's CAS Registry Number is 1401708-83-5.
