Semax

Sharper focus and brain protection, built from a stress hormone with the stress removed.

Evidence: BHuman trials what's this?
Grade B. Russian clinical data and approval, strongest in stroke; no Western replication.
Also known as: Met-Glu-His-Phe-Pro-Gly-Pro · ACTH(4–10) analogue
Class: Synthetic heptapeptide; BDNF inducer. Approved prescription drug in Russia.

The 30-second version

WhatA fragment of ACTH re-engineered so it protects the brain without raising cortisol.

Why people use itFocus, processing speed and mental stamina, often paired with Selank.

The honest catchThe best evidence is for stroke recovery, not for boosting an already-healthy brain.

What it is

Semax was developed at the same Russian institute as Selank, and the two share a stabilising Pro-Gly-Pro tail and a nasal-spray route. It has been a Russian prescription drug since the 1990s and is on the country’s essential-medicines list for stroke and cognitive disorders. That gives it real clinical history, but almost all of it is published in Russian and hasn’t been replicated in large Western trials.

How it works

BDNF surge. In animals, one nasal dose tripled hippocampal BDNF, a "fertiliser" for neurons, within hours.

TrkB up. More BDNF receptors in the hippocampus and cortex, which drives plasticity, learning and memory.

Melanocortin. Neuroprotection without ACTH’s cortisol and stress-axis activation.

Dopamine and serotonin are modulated, giving focus without the jitter or crash of stimulants.

Stroke. Shifts brain immune signalling toward anti-inflammatory mediators.

Semax clears from the blood in minutes, but the BDNF effect lasts for hours to days.

What the research shows

In people: Russian trials in acute ischaemic stroke found nasal Semax gave measurable neuroprotection and better cognitive and motor recovery than standard care¹. Smaller human and imaging studies cover cognitive impairment. In animals: robust BDNF/TrkB data² and well-characterised anti-inflammatory neuroprotection in stroke models³.

A fast, clean focus effect is real. Proof that it enhances a healthy brain is not.

Evidence at a glance

Use	Grade	Best evidence	Main gap	Read
Stroke recovery	BHuman trials	Neuroprotection, better recovery¹	Russian, unreplicated	Strongest use
BDNF, neuroplasticity	ELab & animal	Single dose tripled BDNF²	Animal	Striking
Focus and cognition	DCommunity use	Faster processing reported	Limited human data	Plausible

Dosing: what has been reported

Not a recommendation. These figures describe what was studied or what circulates in practice, kept separate so you can see how solid each one is. Speak with a qualified clinician before acting on any of it.

Setting	Figure	Route	Grade
Approved (Russia), cognition	600–1,200 mcg/day via 0.1% solution, split	Intranasal	B
Approved (Russia), acute stroke	9,000–18,000 mcg/day via 1% solution, within 6–12 h, clinical care only	Intranasal	B
Community	600–1,200 mcg/day in 5–10-day courses with breaks, often with Selank	Intranasal	D

Nasal use is the studied route and the one to prefer. Injectable forms lack that evidence. Take it earlier in the day, because it’s stimulating.

Preparing & storing

Research Semax is reconstituted with bacteriostatic water and made into nasal drops. Refrigerate once mixed. The Pro-Gly-Pro tail gives it good stability.

Timeline: focus within 15–40 minutes, peaking at 1–2 hours and lasting 4–6 hours. BDNF effects build over a course.

Reported side effects

Mild nasal irritation
Overstimulation or poor sleep if dosed high or late
Occasional mild headache
No cortisol rise and no stimulant crash

Who should avoid it

Pregnancy and breastfeeding
Stimulant or psychiatric medication: get medical input (dopamine and serotonin)
A real stroke is an emergency, not something to self-treat

Regulatory status checked Oct 2026

Body	Status	Detail
FDA (US)	Not approved	Research use only.
EMA (EU)	Not approved	—
Russia	Approved	Prescription drug; essential-medicines list.
WADA	Not listed	Low doping relevance.

The NexGen read

A real neuroprotective drug, used as a nootropic

Semax has approval, a striking BDNF mechanism and a clean safety profile. Its strongest data are for stroke. Use it nasally, early in the day, and expect noticeable but modest focus.

References

Gusev EI, Skvortsova VI, et al. Neuroprotective effects of Semax in acute ischemic stroke. Russian clinical trials.
Dolotov OV, Karpenko EA, Inozemtseva LS, et al. Semax upregulates BDNF and TrkB expression in rat hippocampus. 2006. PMID 16996037
Dergunova LV, et al. Semax suppresses pro-inflammatory gene expression during cerebral ischemia-reperfusion.