peptide wiki

Dihexa

aka PNB-0408

Nootropic / Cognitive

Mechanism

Dihexa (PNB-0408) is a small-molecule hexapeptide-like analog of angiotensin IV developed at Washington State University by the Harding/Wright group as a preclinical candidate for Alzheimer's disease and cognitive decline. It is NOT FDA-approved and has never been tested in human clinical trials. The often-quoted claim that it is 'roughly ten million times more potent than BDNF' refers to EC50 comparisons in an in vitro dendritic spine assay, not clinical efficacy.

Identification

CAS number1401708-83-5
Molecular formulaC27H44N4O5
Typical dose2-5 mg/day subcutaneous or 10-40 mg/day oral/intranasal; typical research cycles 4-6 weeks on with 2-4 weeks off
Half-life12.68 days (i.v., rat); 8.83 days (i.p., rat); ~2-4 hours estimated for oral/intranasal routes

Vendors selling Dihexa

VendorSizePriceListed purityTrust
Moglabs 5 mg $40.00 96
Licensed Peptides 10 mg $129.99 95
Peptide Tech $64.99 94
Skye Peptides 8 mg $119.00 90
Peptidology 10 mg $69.99 89
Simple Peptide $109.00 85
Crystal Peptides $114.00 66
Certified Peptides 5 mg $165.00 62
Certified Peptides 50 mg $240.00 62
Ruo Bio 5 mg $38.00
AMC Essentials 5 mg $39.99
Flawless Compounds
Genetic Peptide 5 mg $100.00
Genetic Peptide 10 mg $100.00
Genetic Peptide $200.00
Kimera Chems $121.99
Nextech Labs 4 mg $90.00
Paramount Peptides 8 mg $93.50
Paramount Peptides 30 mg $175.00
Paramount Peptides 10 mg $349.00
Paramount Peptides 10 mg $110.00

Research

Therapeutic Peptides in Orthopaedics: Applications, Challenges, and Future Directions
Rahman OF, Lee SJ, Seeds WA. · Journal of the American Academy of Orthopaedic Surgeons. Global research & reviews (2026) · review

Therapeutic peptides are emerging as promising adjuncts in the management of orthopaedic injuries, grounded in their ability to modulate molecular signaling networks central to cellular medicine.

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Umbilical cord mesenchymal stromal cells-derived HGF inhibits STING-mediated pyroptosis to alleviate cerebral ischemia/reperfusion injury via c-Met/β-catenin/RNF5 pathway
Tang H, Gao N, Gao L, Li Y, Xia Y. · Journal of translational medicine (2026) · animal

BACKGROUND: Pyroptosis plays an essential role in the pathological process of cerebral ischemia/reperfusion (I/R) injury. Hepatocyte growth factor (HGF)-modified stem cells improve brain I/R damage.

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Comparative analysis of small molecule and growth factor-derived human induced pluripotent stem cell-derived hepatocyte-like cells
Asumda FZ, Alzoubi S, Padarath K, Jones K, Kolhe R, Mondal AK, Alptekin A, Zhi W, Lee TJ, Huebert RC, Staff NP, Roberts LR, Kirkeby LA. · Frontiers in cell and developmental biology (2025) · in-vitro

The growth factor and small molecule protocol are the two primary approaches for generating human induced pluripotent stem cell-derived hepatocyte-like cells (iPSC-HLCs). We compared the efficacy of the growth factor and small molecule protocols across fifteen different human iPSC lines.

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Generation and applications of an expandable and mature hiPSC-derived liver organoid
Liu S, Wang Z, Zhu L, Wang L, Zhao T, Han P, Xu Y, Yang L, Hu L, Yan F, Wang X, Cui T, Li C, Yang B. · Acta pharmaceutica Sinica. B (2025) · animal

Organoids have emerged as a powerful tool for modeling liver diseases, drug screening, and personalized treatments. However, they have a limited capacity to generate functional hepatocytes in a reproducible and efficient manner.

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The Occurrence of Illicit Smart Drugs or Nootropics in Europe and Australia and Their Associated Dangers: Results from a Market Surveillance Study by 12 Official Medicines Control Laboratories
Vanhee C, Deconinck E, George M, Hansen A, Hackl A, Wollein U, El-Atma O, Beerbaum N, Aureli F, Borioni A, Poplawska M, Blazewicz A, Roschel K, Marson C, Mendoza Barrios M, Hakkara, et al. · Journal of xenobiotics (2025) ·

In recent years, an increasing number of case reports have mentioned the presence of illicit nootropics, smart drugs or mind doping products on the market.

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Effects of an Angiotensin IV Analog on 3-Nitropropionic Acid-Induced Huntington's Disease-Like Symptoms in Rats
Wells RG, Azzam AF, Hiller AL, Sardinia MF. · Journal of Huntington's disease (2024) · animal

Background Huntington's disease (HD) is a neurodegenerative disorder characterized by motor, cognitive, and psychiatric dysfunction caused by a mutant huntingtin protein.

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Botanical Pesticides: Role of <i>Ricinus communis</i> in Managing <i>Bactrocera zonata</i> (Tephritidae: Diptera)
Akbar R, Manzoor S, Azad R, Makai G, Rahim J, Sheikh UAA, Ali A, Aziz T, Ahmad HI, Ahmed M, Du D, Sun J. · Insects (2024) ·

The melon fruit fly, Bactrocera zonata (Coquillett) (Diptera: Tephritidae), is a notorious pest, posing a significant threat to a wide range of fruits and vegetables, leading to substantial agricultural losses worldwide.

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Chemical approaches targeting the hurdles of hepatocyte transplantation: mechanisms, applications, and advances
Shi H, Ding Y, Sun P, Lv Z, Wang C, Ma H, Lu J, Yu B, Li W, Wang C. · Frontiers in cell and developmental biology (2024) · review

Hepatocyte transplantation (HTx) has been a novel cell-based therapy for severe liver diseases, as the donor livers for orthotopic liver transplantation are of great shortage. However, HTx has been confronted with two main hurdles: limited high-quality hepatocyte sources and low cell engraftment and repopulation rate.

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Efficiently generate functional hepatic cells from human pluripotent stem cells by complete small-molecule strategy
Pan T, Wang N, Zhang J, Yang F, Chen Y, Zhuang Y, Xu Y, Fang J, You K, Lin X, Li Y, Li S, Liang K, Li YX, Gao Y. · Stem cell research & therapy (2022) ·

Background Various methods have been developed to generate hepatic cells from human pluripotent stem cells (hPSCs) that rely on the combined use of multiple expensive growth factors, limiting industrial-scale production and widespread applications.

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Phenotypical, functional and transcriptomic comparison of two modified methods of hepatocyte differentiation from human induced pluripotent stem cells
Li R, Zhao Y, Yourick JJ, Sprando RL, Gao X. · Biomedical reports (2022) ·

Directed differentiation of human induced pluripotent stem cells (iPSCs) into hepatocytes could provide an unlimited source of liver cells, and therefore holds great promise for regenerative medicine, disease modeling, drug screening and toxicology studies.

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AngIV-Analog Dihexa Rescues Cognitive Impairment and Recovers Memory in the APP/PS1 Mouse via the PI3K/AKT Signaling Pathway
Sun X, Deng Y, Fu X, Wang S, Duan R, Zhang Y. · Brain sciences (2021) · animal

The renin-angiotensin system (RAS) is a paracrine RAS within the central nervous system (CNS) and is closely related to Alzheimer's disease (AD). The endogenous hexapeptide angiotensin IV (Ang IV), an important component of the brain RAS, was found to rescue cognitive impairment and recover memory in previous studies.

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Stem cell, Granulocyte-Colony Stimulating Factor and/or Dihexa to promote limb function recovery in a rat sciatic nerve damage-repair model: Experimental animal studies
Weiss JB, Phillips CJ, Malin EW, Gorantla VS, Harding JW, Salgar SK. · Annals of medicine and surgery (2012) (2021) · animal

Background Optimizing nerve regeneration and re-innervation of target muscle/s is the key for improved functional recovery following peripheral nerve damage.

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