Dihexa vs NA-Selank Amidate
Comprehensive side-by-side comparison of mechanisms, dosing, side effects, and research
Also: N-hexanoic-Tyr-Ile-(6) aminohexanoic amide
Dihexa (N-hexanoic-Tyr-Ile-(6) aminohexanoic amide) is a small synthetic peptide built from angiotensin IV, engineered at Washington State University to be orally active and to cross into the brain. The pitch is bold: it is studied as a procognitive compound that may rebuild synaptic connections, and lab claims of extreme potency made it a darling of the nootropic underground. The reality check: every supporting study is in cells or rodents, there are zero human clinical trials, and a foundational 2012 biochemistry paper describing its target was later retracted.
Also: N-Acetyl Selank Amidate, NA-Selank
NA-Selank Amidate is a chemically stabilized version of Selank, a Russian anxiolytic peptide derived from the immune fragment tuftsin. The acetyl group on one end and the amide on the other are there to slow enzymatic breakdown, which is a real and sensible modification. What has not been established is whether that translates into a meaningfully better result than plain Selank in humans.
Key Comparison Insights
- Both peptides belong to the Cognitive category, suggesting similar primary applications.
- NA-Selank Amidate has stronger research evidence (Human Trials) compared to Dihexa (Animal Studies).
Detailed Comparison
| Attribute | Dihexa | NA-Selank Amidate |
|---|---|---|
| Category | Cognitive | Cognitive |
| FDA Status | Not FDA Approved | Not FDA Approved |
| Clinical Status | Pre I II III IV FDA | Pre I II III IV FDA |
| Mechanism of Action | Dihexa is derived from angiotensin IV, a fragment of the renin-angiotensin system that has long been linked to memory in animal work. The leading hypothesis is that it acts on the hepatocyte growth factor (HGF) and its receptor c-Met, a growth-factor system that drives the formation of new dendritic spines and synapses. In cultured hippocampal neurons, dihexa and related angiotensin IV analogs increase spine density, and that effect disappears when the HGF/c-Met system is blocked, which is the main evidence the pathway matters. It is worth being blunt that the exact molecular interaction has been contested, since the original paper proposing direct HGF binding was retracted, so the mechanism is best treated as a working hypothesis rather than settled fact. | Selank is a synthetic analog of tuftsin, a naturally occurring immunomodulatory peptide fragment. Its reported mechanism has two strands. The first is modulation of GABAergic signalling, which is the basis of its anxiolytic reputation, achieved without the sedation, tolerance or dependence associated with benzodiazepines. The second is an effect on the balance of monoamines and on BDNF expression, which is where the cognitive and mood claims come from. It also retains some of tuftsin's immunomodulatory activity, including effects on interleukin expression. The N-acetylation and C-terminal amidation in this version block the exopeptidases that would otherwise clip the peptide quickly, extending how long it survives after administration. That is a pharmacokinetic change, not a new mechanism. |
| Common Dosing | 5-20 mg oral or sublingual daily Once daily, effects can last up to 10 days | 250-500 mcg daily (intranasal) Once or twice daily |
| Administration | Oral, sublingual, or intranasal | Intranasal is the standard route. Subcutaneous is reported but less common. |
| Typical Duration | Cycles of 2-4 weeks | Community protocols commonly report 2-4 weeks, though Selank's clinical use does not indicate a dependence risk requiring cycling |
| Best Time to Take | Morning | Morning or split across the day |
Possible Side Effects May vary by individual |
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| Research Summary | The published evidence on dihexa is entirely preclinical. Harding, McCoy and colleagues at Washington State University reported that metabolically stabilized angiotensin IV analogs, including dihexa, restored cognition in scopolamine-impaired and aged rats and stimulated synaptogenesis in cultured neurons (J Pharmacol Exp Ther, 2012 and follow-ups). A 2014 study tied the procognitive and synaptogenic effects of these analogs to the HGF/c-Met system. There are no registered human clinical trials and no published human safety or pharmacokinetic data, so dosing, long-term safety and whether any of the rodent benefit translates to people are all unknown. One important caveat for anyone reading the primary literature: the 2012 paper that first proposed dihexa as an HGF/Met modifier was formally retracted in 2024, which weakens the strongest mechanistic claim. Treat dihexa as an interesting research molecule with promising animal data and a notable evidence gap, not as a proven cognitive enhancer. | Selank itself has a real research base, almost all of it Russian, including clinical work in generalised anxiety disorder where it performed comparably to benzodiazepines without the sedation and withdrawal profile, plus animal work supporting the BDNF and monoamine effects. That literature is genuine but it is largely published in Russian journals, has not been replicated in large Western trials, and has not been through FDA or EMA assessment. The amidate variant specifically has essentially no independent published pharmacology. The stability argument is chemically sound and is the same modification used across many research peptides, but nobody has published a human comparison showing it outperforms standard Selank at equivalent doses. Treat the parent compound's evidence as real but geographically narrow, and the variant's advantage as plausible rather than demonstrated. |
Frequently Asked Questions: Dihexa vs NA-Selank Amidate
What is the difference between Dihexa and NA-Selank Amidate?
Dihexa is a cognitive peptide that dihexa (n-hexanoic-tyr-ile-(6) aminohexanoic amide) is a small synthetic peptide built from angiotensin iv, engineered at washington state university to be orally active and to cross into the brain. the pitch is bold: it is studied as a procognitive compound that may rebuild synaptic connections, and lab claims of extreme potency made it a darling of the nootropic underground. the reality check: every supporting study is in cells or rodents, there are zero human clinical trials, and a foundational 2012 biochemistry paper describing its target was later retracted. NA-Selank Amidate is a cognitive peptide that na-selank amidate is a chemically stabilized version of selank, a russian anxiolytic peptide derived from the immune fragment tuftsin. the acetyl group on one end and the amide on the other are there to slow enzymatic breakdown, which is a real and sensible modification. what has not been established is whether that translates into a meaningfully better result than plain selank in humans. The main differences lie in their mechanisms of action and clinical applications.
Which is better, Dihexa or NA-Selank Amidate?
Neither is universally "better" - the choice depends on your specific goals. Dihexa is typically used for cognitive purposes, while NA-Selank Amidate is used for cognitive. Always consult with a healthcare provider to determine which may be appropriate for your situation.
Can Dihexa and NA-Selank Amidate be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using Dihexa and NA-Selank Amidate together should only be considered under medical supervision, as both compounds have their own side effect profiles and potential interactions. Research on their combined use may be limited.