Semax vs Selank: which one, and can you use both?
Two peptides from the same lab with different jobs. How they differ, and how FOCUS-01 and CALM-02 fit a day.
01The short version
Semax is for the working hours: attention, memory, learning, drive. Selank is for the other end of the day: everyday stress, calm without sedation, clear thinking under pressure. They come from the same Moscow institute, share the same Pro-Gly-Pro tail, and are both nasal sprays, but they do different jobs.
In the COGENT range Semax is FOCUS-01 and Selank is CALM-02. Many people use both, at different times, which is why we sell them as The Pair.
02Same lab, different parents
Both peptides were designed at the Institute of Molecular Genetics of the Russian Academy of Sciences, and both use the same trick: take a short fragment of a naturally occurring peptide, then attach Pro-Gly-Pro to stop the body breaking it down too quickly.
Semax (Met-Glu-His-Phe-Pro-Gly-Pro) is built on a fragment of ACTH, the hormone fragment that researchers found influenced attention and learning. Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) is built on tuftsin, a peptide involved in immune signalling that was found to have calming effects in animal models. Semax was registered in Russia in 1994, Selank in 2009.
03How they differ in effect
| Semax (FOCUS-01) | Selank (CALM-02) | |
|---|---|---|
| Built for | Attention, memory, learning, drive | Everyday stress, calm, clear thinking |
| Feels like | A quiet sharpening that lasts the day | The background hum turned down, without drowsiness |
| Main mechanism | BDNF and TrkB upregulation [3]; dopamine and serotonin modulation [4] | Modulation of GABA-related signalling; BDNF; effects on serotonin metabolism |
| Human evidence | Controlled volunteer study: attention and short-term memory improved [1] | Russian clinical studies in anxiety-type indications; smaller and less accessible |
| Best time | Morning, before focused work | Late afternoon or evening, or before a stressful event |
| Stimulant? | No | No; and not a sedative either |
The practical difference is simple. If the problem is that you cannot hold attention or the afternoon falls apart, that is Semax. If the problem is that you are wired, tense, and cannot think clearly because of it, that is Selank. If it is both, at different times of day, that is The Pair.
04Can you use both?
Yes, and it is the most common way people use them, but not as a stack taken together. The sensible pattern is Semax in the morning before the work that matters and Selank later, when you want to come down without going flat. There is no reason to take both in the same breath, and no study that did.
Keep to each product’s own limit (four sprays a day for each), and treat the first week as a trial: one at a time for a couple of days each, then both, so you know what each one is doing.
05Which one first?
Most people should start with Semax. Its human evidence is clearer, its use case is more specific, and the benefit is easier to notice: you either got more done in the block than usual or you did not. Add Selank if the evenings are the problem, or if stress is what is eating the focus in the first place.
Read next: the Semax dosage guide and side effects and safety. Every claim above is cited on the research page.
This article is general information, not medical advice. FOCUS-01 and CALM-02 are not licensed medicines and are not intended to diagnose, treat, cure or prevent any condition. If you take prescribed medication, are pregnant or breastfeeding, or are under 18, speak to a doctor before using any peptide product.
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