Cognition
Semax + Selank
Two Russian-developed peptides, both intranasal, run together for cognition and anxiety. The shared-origin story is repeated everywhere and sourced nowhere primary.
At a glance
- Sold as
- Separate vials
- The evidence
- No clinical trial has tested Semax and Selank as a combination protocol in humans. Both are unlicensed outside Russia. Semax was recommended by FDA's advisory committee 8–5–1 for cerebral ischaemia, migraine and trigeminal neuralgia, not for healthy-adult cognition, which is what the community runs it for.Combination-specific research is limited. Treat each compound’s evidence as separate unless a study of the combination itself is named here, and review the complete plan with a qualified clinician.
Running this stack, with the schedule, the vials it takes and a log of what you took, happens in the app: Claritide for iPhone.
Why people explore it
Common reasons for exploring it
- People who have already read the Russian stroke literature and want the community practice put next to it
- Anyone deciding whether the community cognitive dose bears any relationship to a studied dose
Where clinician input matters
- Anyone expecting the healthy-adult cognitive claim to be supported. It is not studied.
- Pregnant or nursing, under 25
- Drug-tested athletes, given that the status is genuinely unresolved
The science
Read the compound mechanisms
Semax is built from the ACTH(4–10) fragment with a Pro-Gly-Pro tail attached. That tail is the engineering: it resists breakdown by enkephalinase and exopeptidases, which is why the molecule lasts appreciably longer in the body than the bare ACTH fragment would. The proposed primary action is rapid upregulation of brain-derived neurotrophic factor and its TrkB receptor in the hippocampus, the growth-factor signalling that supports synaptic plasticity. That direction is corroborated in humans: the 2018 stroke study measured plasma BDNF and found it increased. Serotonergic and dopaminergic modulation are also proposed, and those finer mechanistic claims come from vendor material rather than from published pharmacology.
Our material describes Selank as working through GABA modulation with an anxiolytic effect. GABA is the brain's primary calming neurotransmitter; compounds that modulate it reduce the nervous system arousal that keeps people awake. That places Selank in a different position from DSIP, which acts on sleep depth, and from the GHRPs, which act through growth hormone. Selank targets the anxiety that prevents sleep rather than the sleep itself. Our sources do not describe the receptor-level mechanism further.
Commonly researched ranges
| Compound | Amount | Frequency | Timing |
|---|---|---|---|
| Semax | 600–1,200 mcg | Per day, split across the day | Intranasal, 0.1% solution |
| Selank | None published | No sourced figure | Intranasal |
- Semax: Vendor-tier community range. The verified trial figure is different and much larger: 6,000 mcg/day intranasally for 10 days, two courses with a 20-day gap, in ischaemic stroke rehabilitation. The "all doses before 2 PM" rule and the "dose Selank first, Semax 15–30 minutes later" sequencing are vendor claims with no label or trial behind them, and are not reproduced here.
- Selank: Our sources publish no figure we can stand behind for Selank in this pairing. Both are registered medicines in Russia, but not alike: Selank is sold without a prescription, for anxiety, and Semax needs one. Treating the two identically is unsupported.
- Duration
- No sourced duration for the combination. The one verified Semax protocol ran two 10-day courses with a 20-day gap, in stroke rehabilitation.
Mixing each compound
Not established in available literature. Use the figures printed on your own vial.
Not established in available literature. Use the figures printed on your own vial.
What it costs
Not established in available literature for any compound in this stack. Claritide’s cost engine will track what you actually pay once you log a vial.
Cautions
- The origin story is reported, not verified. The claim that both came out of Russia's Institute of Molecular Genetics traces to three vendor blogs. PubMed shows recurring authors consistent with it, and there is no primary confirmation.
- Do not extend this to the three-compound version that adds Dihexa. Dihexa has never been tested in a human, has no human dose, and activates the HGF/c-Met pathway, a real contraindication for anyone with a cancer history.
- Semax's side effect and contraindication lists in our sources are empty. That is absence of research, not evidence of safety.
- No primary pharmacokinetic source for Semax exists that we could locate. Vendor pages give "~20 min" and "0.5–2 h" and disagree with each other.
- Neither is named on the WADA list. Both are registered as medicines in Russia, so the S0 catch-all may not cover them, and we do not state a status for either. We will not call either one banned or clear.
Absence from this list does NOT mean safety. It means lack of research.
Every stack here is free to read, and it stays free. Your own schedule, vials and log live in the app: Claritide for iPhone.