01 How it works
Semax is built on the ACTH(4–10) fragment, with an extra tail that makes it last longer. In animal studies it raises BDNF — a growth factor that supports brain cells — and influences dopamine and serotonin. In Russia it has been used after strokes.
02 Common uses
03 Run profile
A gentle first week, stepped up over the first month, then held. Three times a week in the morning — not late in the evening.
The profile shows the shape. Ask for the numbers for your vial, your goal and your timeline.
04 Pairs well with
05 What to watch for
Mild headache, occasionally dizziness or nausea, usually passing. Nasal irritation if used as a spray. New or worsening anxiety or sleep disruption is worth flagging. No dependence or withdrawal has been reported.
06 Evidence & status
Not FDA-approvedMostly animal research plus clinical use and studies in Russia; little Western clinical trial data.
Approved as a medicine in Russia; not FDA-approved. An FDA advisory panel recommended it 8–5 for the 503A compounding list in July 2026, a non-binding vote. On 28 October 2026 HHS issued an interim enforcement-discretion policy that lets state-licensed pharmacies and physicians compound single-ingredient Semax, and only as a nasal product, not injected while FDA rulemaking continues. It is still not on the 503A list, and there is no final FDA decision.
Sources
- [Effectiveness of semax in acute period of hemispheric ischemic stroke (a clinical and electrophysiological study)]Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova, 1997 · Clinical trial
- Semax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampusBrain Research, 2006 · Reference
- Semax, an ACTH(4-10) analogue with nootropic properties, activates dopaminergic and serotoninergic brain systems in rodentsNeurochemical Research, 2005 · Reference
- Development of Peptide Biopharmaceuticals in RussiaPharmaceutics, 2022 · Review
- July 23-24, 2026: Meeting of the Pharmacy Compounding Advisory CommitteeU.S. Food and Drug Administration, 2026 · Regulator document
- HHS Draft Policy Eases Enforcement on 6 Compounded PeptidesThe American Journal of Managed Care (AJMC), 2026 · Regulator document
- The Prohibited ListWorld Anti-Doping Agency, 2026 · Regulator document
Status and sources last checked November 3, 2026. Something out of date? Tell us.
07 How long until it works
In Russia, Semax is a registered medicine with the longest clinical record of any peptide in this category, but that record is for conditions like acute stroke, where it was given in the first days and effects were measured over the treatment course; there is no Western trial of Semax for focus or brain fog in healthy people. In animals it raises BDNF and acts on dopamine and serotonin signalling within hours of a dose.
People using it for focus describe a same-day effect, sharper over the first week, which is why the run profile holds a steady three-times-a-week rhythm rather than a build-up. That is common use, not a measured result.
08 Semax vs Selank
They are usually chosen between, or together. Semax is built on the ACTH(4–10) fragment and, in animal work, raises BDNF and activates dopamine and serotonin pathways: the focus one. Selank is built on tuftsin and acts on the GABA system and enkephalin breakdown: the calm one. Both were developed by the same Russian institute, both are registered medicines in Russia, and both are taken three times a week in the morning on this site.
The practical rule people use: brain fog, low drive or trouble concentrating points to Semax; a busy, anxious mind points to Selank; and the pair is common for people who want both. Neither has a Western trial, and nothing has tested the combination.
The Selank dossier →09 Stacking
Selank is the usual partner (see above), and NAD+ for mental energy. No study has tested either pairing. Because Semax is a morning peptide for most people, it is kept away from evening doses of anything else.
10 Where it stands legally
Semax is approved as a medicine in Russia and not approved in the US or Europe. In July 2026 the FDA’s advisory committee voted 8–5 to recommend it for the 503A compounding list, against FDA reviewers’ advice. On 28 October 2026 HHS issued an interim policy under which it will not take enforcement action against licensed pharmacies and physicians compounding single-ingredient Semax, but only as a nasal product. Injected Semax, which is how the schedule on this site is written, is outside that policy.
In sport, WADA’s S0 category covers substances with no approval from any government health regulator. Semax is approved in Russia, so whether S0 catches it is not clear-cut; it is not named elsewhere on the list. Tested athletes should put the question to their anti-doping body before using it.
11 FAQ
Is it a stimulant?
No. People describe clearer focus rather than a caffeine-like buzz.
Semax or Selank?
Semax leans toward focus and drive; Selank toward calm. Many use both.
Why not in the evening?
Some find it alerting enough to interfere with sleep.
Is Semax a nasal spray or an injection?
In Russia it is sold as a nasal spray, and the October 2026 HHS compounding policy covers only the nasal form. This site’s schedule is written for vials; the calculator above gives the units for that.
Is Semax legal in the US?
It is not approved. Since October 2026 pharmacies may compound a nasal version under an HHS enforcement policy; that is not an approval and can be withdrawn.
Is Semax banned in sport?
Not named on WADA’s list, and because it is approved in Russia the S0 “non-approved” category may not apply. Check with your anti-doping body; this page cannot settle it.
Does Semax raise cortisol?
It is built from a fragment of ACTH, the hormone that triggers cortisol, but the fragment used lacks the part that does so, and the animal work on this page shows effects on BDNF and neurotransmitters rather than cortisol. Human hormone data are lacking.
Educational information only — not medical advice. The Daily Stack does not sell or supply any products. Talk to a licensed healthcare professional about your own health decisions.