Dihexa
N-hexanoic-Tyr-Ile-(6) aminohexanoic amide
An angiotensin IV analog studied in rat models of memory loss
Dihexa is a synthetic peptide derived from angiotensin IV, modified at both ends to resist breakdown. It was developed in a Washington State University lab, and in rat studies it crossed the blood-brain barrier and worked when given by mouth. It has been studied for memory and learning in rats with induced cognitive impairment and is used informally as a nootropic. As of October 2026, no human study of dihexa has been published, and the 2014 paper behind its proposed mechanism was retracted in April 2025. It isn't approved as a medicine anywhere.
Read the research profile for mechanisms, citations, and safety context before comparing vendors. View the Dihexa research profile.
Key Benefits
Mechanism of Action
The proposed mechanism involves hepatocyte growth factor (HGF) and its receptor, c-Met. Papers from the lab that developed dihexa reported that it binds HGF and boosts c-Met signaling, and linked this to more dendritic spines and synapses (synaptogenesis) in cultured rat neurons and to better maze performance in impaired rats. The key 2014 paper tying these effects to HGF/c-Met was retracted in April 2025, along with a related 2012 paper; the journal had flagged both in 2021 over possible image manipulation. The 2013 rat study behind the synapse and memory findings has carried an expression of concern since 2021 but hadn't been retracted as of October 2026. A 2021 study from a different group in China reported improved memory in a mouse model of Alzheimer's disease and pointed to a different pathway (PI3K/AKT). How dihexa works in people hasn't been studied.
Dosing Guidelines
Typical Dose
5-20 mg per application (vendor and community guides)
Frequency
Every other day or 3x per week (community guides)
Duration
4-8 weeks (community guides)
Note: No human dose has been studied. These figures come from vendor and community guides; one vendor derives the 5-20 mg range by scaling rat doses, which is a conversion rather than a tested dose. Some guides describe applying dihexa to the skin dissolved in DMSO, while that vendor's summary of forum discussion says most users take it sublingually or orally. Injection is described less often. In rats, oral doses went up to 2 mg/kg.
Research & Studies
Our dihexa profile: what it is, the rat and cell research behind it, and how it's reported to be used.
Read Full ResearchA nasal peptide registered as a drug in Russia and backed by small Russian stroke studies. It's often compared with dihexa as a nootropic.
Read Full ResearchA Russian-registered nasal peptide studied for anxiety in small trials without placebo control. It's another common nootropic comparison.
Read Full ResearchPotential Side Effects
Reported side effects may include:
- - No human safety data; FDA found no human exposure data (2026)
- - Brain fog or overstimulation at high doses (anecdotal)
- - Skin irritation from the DMSO carrier when applied to the skin
- - Headaches or irritability (anecdotal)
- - Theoretical cancer risk via HGF/c-Met activation (untested)
- - Mood changes (anecdotal)
This information is for research purposes only. Always consult with a healthcare professional.
Popular Stacking Options
Dihexa + BPC-157
Vendor stacks pair it with dihexa for recovery after brain or nerve injury. No study has tested the combination, and BPC-157's evidence for these uses comes almost entirely from rodents.
Shop this stackDihexa + GHK-Cu
Some vendor stacks add it, citing anti-inflammatory effects reported in lab studies. It hasn't been tested alongside dihexa.
Shop this stackDihexa + Ipamorelin
Vendor stacks sometimes add it to raise growth hormone. Any benefit for cognition is speculative, and the combination is untested.
Shop this stackFrequently Asked Questions
How is Dihexa different from other nootropics like racetams or Semax?
The claimed difference is the mechanism. Many nootropics are thought to act on neurotransmitters, while dihexa was described as working through HGF/c-Met signaling to build new synapses, based on rat and cell studies. The key paper behind that mechanism was retracted in April 2025, so the claim rests on weaker ground than vendor pages suggest. The evidence also differs: semax is a registered drug in Russia with small human stroke studies, while dihexa had no published human data as of October 2026. No one has compared dihexa with racetams or semax, so whether it's more potent or longer-lasting is unknown.
How is Dihexa usually used?
No human dose or route has been studied. Vendor and community guides describe applying it to the skin dissolved in DMSO, a solvent that carries compounds through the skin, or taking it sublingually or by mouth. DMSO often irritates the skin, and the Alzheimer's Drug Discovery Foundation notes it can cause serious side effects at high concentrations. In the published rat studies, dihexa was given by mouth, by injection, or directly into the brain.
Is Dihexa safe? What's the cancer risk?
There's no human safety data. As of October 2026, FDA says it has found no human exposure data for dihexa acetate by any route, and the Alzheimer's Drug Discovery Foundation found no long-term safety studies in animals either. In rats, dihexa had a half-life of about 9-13 days, so it stays in the body for a long time. The main theoretical concern is cancer: HGF and its receptor c-Met are overactive in many cancers, and boosting that pathway could in theory help tumors grow. Nobody has tested this. Community guides advise against use with a personal or family history of cancer, and anyone weighing health risks should talk to a healthcare professional.
How long does it take for Dihexa to work?
No study has measured this in people. Some users report better focus or mental clarity within the first week or two, but these reports are unverified, and the 4-8 week duration in vendor guides isn't based on a human trial. In rats, dihexa improved maze performance in animals with induced memory problems over several days of testing. It didn't improve memory in rats with normal cognition.
More from this category
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DSIP
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Selank
A Russian-registered peptide studied in small trials for anxiety
Semax
A Russian-registered nootropic peptide studied for stroke recovery and cognition
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