Selank vs Dihexa
Comprehensive side-by-side comparison of mechanisms, dosing, side effects, and research
Also: Selanc, TP-7
Selank is a synthetic seven-amino-acid peptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro) built from the natural immune peptide tuftsin, with a small chemical tweak to make it last longer in the body. It was developed in Russia as an anti-anxiety and nootropic agent and is approved there for generalized anxiety disorder, but it has no FDA or EMA approval and almost no Western clinical data. The pitch is calm and focus without the sedation, dependence, or withdrawal that come with benzodiazepines.
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.
Key Comparison Insights
- Both peptides belong to the Cognitive category, suggesting similar primary applications.
- Selank has stronger research evidence (Human Trials) compared to Dihexa (Animal Studies).
Detailed Comparison
| Attribute | Selank | Dihexa |
|---|---|---|
| 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 | Selank seems to work through several overlapping systems rather than one tidy target. It influences GABA signaling, the brain's main calming neurotransmitter system, which likely accounts for its anti-anxiety effect. It also slows the breakdown of enkephalins, the body's own opioid-like peptides involved in mood and stress, which is a mechanism entirely different from benzodiazepines or SSRIs. Animal work additionally points to effects on serotonin and dopamine balance and on BDNF, a growth factor tied to learning and neuron health. These pathways are well documented in rodents; the picture in humans is inferred rather than directly measured. | 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. |
| Common Dosing | 250-500 mcg intranasal 2-3x daily 2-3x daily, intranasal | 5-20 mg oral or sublingual daily Once daily, effects can last up to 10 days |
| Administration | Intranasal spray (most common), subcutaneous injection | Oral, sublingual, or intranasal |
| Typical Duration | 14-21 days typical | Cycles of 2-4 weeks |
| Best Time to Take | Morning or as needed for anxiety | Morning |
Possible Side Effects May vary by individual |
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| Research Summary | Most of the rigorous data is preclinical and Russian. In rodents, Selank shows consistent anxiety-reducing and mild cognitive effects, and one PMC-indexed study found it enhanced diazepam's anti-anxiety effect under chronic stress. The main human clinical reference is a Russian comparative trial by Zozulia, Neznamov, and colleagues in patients with generalized anxiety disorder and neurasthenia, reporting that Selank's anxiolytic effect was comparable to the benzodiazepine medazepam on standard rating scales, with added anti-fatigue benefits and changes in enkephalin activity. The honest caveat: that trial was relatively small, the published English abstract gives qualitative results rather than hard effect sizes and p-values, and it has not been replicated by independent Western groups. So the evidence supports a real but modestly studied anxiolytic, mostly validated within the regulatory system that approved it. | 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. |
Frequently Asked Questions: Selank vs Dihexa
What is the difference between Selank and Dihexa?
Selank is a cognitive peptide that selank is a synthetic seven-amino-acid peptide (thr-lys-pro-arg-pro-gly-pro) built from the natural immune peptide tuftsin, with a small chemical tweak to make it last longer in the body. it was developed in russia as an anti-anxiety and nootropic agent and is approved there for generalized anxiety disorder, but it has no fda or ema approval and almost no western clinical data. the pitch is calm and focus without the sedation, dependence, or withdrawal that come with benzodiazepines. 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. The main differences lie in their mechanisms of action and clinical applications.
Which is better, Selank or Dihexa?
Neither is universally "better" - the choice depends on your specific goals. Selank is typically used for cognitive purposes, while Dihexa is used for cognitive. Always consult with a healthcare provider to determine which may be appropriate for your situation.
Can Selank and Dihexa be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using Selank and Dihexa 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.