Nootropics · Comparison
Semax vs Selank: Which Peptide for Focus, Which for Calm
They are usually mentioned together because they do opposite jobs. One sharpens, one settles. Most people who run both keep them in separate lanes.
Razumna editorial · 6 min read · Updated June 2026
The short answer
Semax and Selank are both intranasal Russian peptides that raise BDNF, but they point in opposite directions. Semax leans toward focus, drive, and stress resilience; Selank leans toward calm and anxiety reduction without sedation. Neither is a stimulant and neither builds tolerance. People who use both run Semax for clarity and Selank to take the edge off, often on the same day, spaced a few minutes apart.
Same family, opposite jobs
Both are short peptides developed in Russia, both are taken as nasal drops, and both raise neurotrophic signaling (BDNF) rather than flooding a neurotransmitter the way a stimulant does. That shared mechanism is why they are mentioned in the same breath. The difference is direction. Semax pushes toward focus and drive; Selank pulls toward calm. If you think of them as a throttle and a brake on the same system, you have the right model.
What Semax does
Semax is an ACTH(4-7) analog. A single intranasal dose raises BDNF and TrkB signaling in the hippocampus and modulates dopaminergic and serotonergic tone (Dolotov et al., 2006). The felt effect is clarity and stress resilience for 4 to 8 hours, no jitter, no crash. The full breakdown is in the Semax guide.
What Selank does
Selank is a tuftsin-derived peptide that modulates the GABAergic system, raises endogenous enkephalins, and upregulates BDNF. In Russian trials it matched the anxiolytic effect of benzodiazepines without the grogginess or sedation (Zozulia et al., 2008). Its plasma half-life is only minutes, but because it works by shifting gene expression, the effect builds over a course and persists for roughly a week (Volkova et al., 2016).
Dosing both
Semax 0.1% delivers roughly 50 micrograms per drop; a common protocol is 2 to 3 drops per nostril, 1 to 3 times a day. Selank 0.15% delivers roughly 75 micrograms per drop; the generalized-anxiety trial used about 450 micrograms 3 times a day, which is around 2 to 3 drops per nostril. Start both at the low end. When running them together, space the drops a few minutes apart so one does not wash the other out.
Which to choose
- Pick Semax if your bottleneck is focus, motivation, or holding attention through a long block.
- Pick Selank if your bottleneck is anxiety, overthinking, or a wired feeling you want to take down without getting sleepy.
- Run both if you want clarity and calm at once, which is the pairing most people land on.
Neither is approved Western medicine, both should be refrigerated, and neither should be combined carelessly with depressants in Selank's case. This is information, not medical advice.
Products in this note
Common questions
Can I take Semax and Selank at the same time?
Yes, that is the classic pairing: Semax for focus, Selank for calm. Both are intranasal and dose on a similar schedule. Space the drops a few minutes apart.
Do either of them build tolerance?
No notable tolerance or withdrawal has been documented for either in the clinical literature. That is a large part of why people use them instead of stimulants or benzodiazepines.
Which one is better for anxiety?
Selank. It modulates GABAergic tone and matched benzodiazepine-level anxiolytic effect in Russian trials without the sedation. Semax is the focus side of the pair.
Sources
- Dolotov OV et al. Semax regulates BDNF and trkB in rat hippocampus. Brain Res 2006 (PMID 16996037)
- Zozulia et al. Selank vs medazepam in generalized anxiety, 2008 (PMID 18454096)
- Volkova et al. Selank and GABAergic gene expression. Frontiers in Pharmacology 2016
This article is information, not medical advice. Razumna does not name compounds as treatments for any condition.
Keep reading