Semax vs Selank

Same Russian lab, two different jobs

They are constantly mentioned together and often stacked, but they were built for different problems. Semax derives from a fragment of ACTH with the hormonal activity stripped out and is aimed at focus, memory and stroke recovery. Selank derives from tuftsin, an immune peptide, and is aimed at anxiety, and Russian trials compared it to benzodiazepines without the sedation or dependence. Both are approved as nasal medicines in Russia and essentially unknown to Western regulators, and both rest on trials that no independent group has replicated.

Cerebral cortex tissue showing a few pyramidal neurons and supporting glial cells.

Semax Cognitive & neuro Full entry →

Two neuronal dendrites and several nearby axon terminals in a quiet blue neural tissue microenvironment.

Selank Cognitive & neuro Full entry →

Semax compared with Selank
	Semax	Selank
Evidence behind it	Human trials	Human trials
Worth knowing	Same caveat: approved and studied almost entirely in Russia, with limited Western replication.	Trials are Russian, small, and not independently replicated.
Approval	Approved · Russia	Approved · Russia
Category	Cognitive & neuro	Cognitive & neuro
What it is	A seven-amino-acid peptide developed in Russia from a fragment of the hormone ACTH, with a Pro-Gly-Pro tail added for stability. It has none of ACTH's hormonal activity. It raises BDNF in the brain and is studied for stroke recovery, attention and memory.	A seven-amino-acid peptide developed in Russia from tuftsin, a natural immune peptide, with three amino acids added for stability. It is studied for calming anxiety without sedation and for effects on memory, GABA signaling, BDNF and immune messengers.
How it works	A fragment of ACTH with the hormonal activity stripped out and a Pro-Gly-Pro tail added for stability. It raises BDNF in the brain along with serotonin and dopamine.	A synthetic analogue of tuftsin with four extra residues for stability. It influences GABA and monoamine signalling and raises BDNF, which is the proposed route to anxiety reduction without sedation.
What studies report	Improved recovery after ischemic stroke in Russian trials Better attention, memory and mental stamina in healthy volunteers and students Raises BDNF in the brain	Anxiety reduction comparable to a benzodiazepine in Russian trials, without sedation or dependence Improved attention and memory measures Effects on BDNF, GABA and serotonin signalling
Dosing	From studies Intranasal, in courses over 10–14 days — Russian stroke and cognitive trials. Reported improvement in recovery measures Reported, not evidence Used intranasally during cognitively demanding periods, then stopped Cycled rather than taken continuously	From studies Intranasal, daily over 14 days — Russian generalised anxiety trials. Anxiety reduction comparable to benzodiazepines, without sedation Reported, not evidence Used situationally rather than daily Often paired with Semax
Why people take it	Focus, memory and mental staminaStroke recoveryMood	Anxiety without sedationFocus under stressMood
In practice	A nootropic-community staple, usually as a nasal spray Used during cognitively demanding periods — exam seasons, deadlines — then stopped Commonly cycled rather than taken continuously	Used as a nasal spray situationally for anxiety, where a benzodiazepine would sedate Often paired with Semax, one for calm and one for drive
Route	Intranasal spray	Intranasal spray

Rows describing reported use say what people do, not what has been shown to work. Evidence strength is graded the same way across the whole library, so the two columns are directly comparable.

Read the full entries

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Educational information only. Nothing here is medical advice, a dosing protocol, or a recommendation to use any compound. Comparing two compounds is not a suggestion to take either one. Talk to a licensed clinician before acting on anything you read here. How to read these entries.