Semax vs Selank
Two Russian nootropic peptides that get confused constantly. Focus or calm?
Reviewed by the amino101 editorial team. , first published .
Semax and Selank come from the same Moscow institute, are both used as nasal drops in Russia, and are both short peptides that barely cross into the blood. That is where the similarity ends. Semax is a fragment of ACTH and pushes BDNF, attention, and drive. Selank is a tuftsin analog that acts on the GABA and enkephalin systems and takes the edge off anxiety without sedation. One is an accelerator, the other a stabilizer.
| Semax | Selank | |
|---|---|---|
| Typical dosage | 200 to 600 mcg | 250 to 750 mcg |
| Frequency | one to three times daily | one to three times daily, or as needed |
| Route | Intranasal, Subcutaneous | Intranasal, Subcutaneous |
| Half-life | a few minutes in blood | minutes in blood |
| Cycle | 10 to 20 days | 2 to 3 weeks |
| Research level | Well researched | Limited research |
| Human trials | Small pilots | Small pilots |
| Status | Prescription drug in Russia, not FDA approved | Prescription anxiolytic in Russia, not FDA approved |
| Effects timeline | alertness within 15 to 30 minutes of a dose; steadier focus and mood over 1 to 2 weeks | calm within about 30 minutes of a dose; a steadier baseline over 1 to 2 weeks |
Key differences
Semax vs Selank dosage
Dosage patterns reported in research and community protocols, by goal. Taken from each compound page. Not a prescription.
| Goal | Dosage | Frequency |
|---|---|---|
| Daily focus | 200 to 300 mcg | once or twice daily |
| Cognitive complaints, full course | 300 to 600 mcg | two to three times daily |
| Injected alternative | 200 to 400 mcg | once daily |
| As needed before demanding work | 200 mcg | single dose |
| Goal | Dosage | Frequency |
|---|---|---|
| Baseline anxiety, full course | 250 to 500 mcg | two to three times daily |
| Before a stressful event | 250 to 500 mcg | single dose as needed |
| Injected alternative | 250 to 500 mcg | once daily |
| Higher dose trial | 750 mcg | once daily |
Convert any of these to syringe units in the dosage calculator.
Side effects compared
- ▲Nasal irritation, dryness, and occasional nosebleeds
- ▲Restlessness or irritability, mainly at higher doses
- ▲Trouble sleeping when dosed late in the day
- ▲Occasional headache
- ▲Hair thinning reported anecdotally by a minority of long-term users
- ▲Nasal irritation with repeated spraying
- ▲Fatigue or emotional flatness at higher doses
- ▲Mild headache
- ▲Occasional drowsiness
- ▲No noticeable effect at all for a fair share of users
Which should you choose?
Semax is the pick when the complaint is low drive, poor concentration or mental fatigue. It pushes BDNF and dopamine signaling, so the effect is activating, and 200 to 600 mcg intranasal in the morning is the common pattern. Skip it if you already run anxious or sleep badly.
Selank is the pick when the problem is anxiety, overthinking or poor stress tolerance. It modulates GABA and protects enkephalins, so the feel is steadier rather than sharper, at 250 to 750 mcg intranasal one to three times daily. It is also the one to try if Semax made you edgy.
Pick by the problem, not by which one sounds better. Trouble concentrating, low drive, mental fatigue: Semax. Anxiety, overthinking, poor stress tolerance: Selank. Plenty of people run both, Semax in the morning and Selank in the afternoon or evening, and the combination is sold as a single spray by several vendors for that reason. Neither has a large Western trial, so treat the reported effects as community experience backed by modest Russian studies.
Stacking: Semax morning, Selank afternoon or evening. Sold combined by several listed vendors.
Semax is a seven-amino-acid peptide based on a fragment of ACTH, developed in Russia as a nasal drug for stroke recovery and cognitive impairment. People use it for focus, mental stamina, and mood support.
Selank is a seven-amino-acid peptide derived from the immune peptide tuftsin, approved in Russia as a nasal anti-anxiety drug. People use it for calm focus without sedation.
Semax vs Selank: frequently asked
Can you take Semax and Selank together?
Yes. They come from the same institute, act on different systems, and are often used together in Russian practice. The usual split is Semax in the morning for focus and Selank in the afternoon or evening for calm. Several vendors sell them as one spray; see the Semax and Selank stack.
Which is better for anxiety, Semax or Selank?
Selank. It was developed as an anxiolytic and has small Russian trials comparing it to benzodiazepines. Semax is activating and can make anxiety worse in some people.
Which is better for focus and studying?
Semax. Its BDNF and dopamine effects are the reason people use it before focused work. Selank gives calm focus for some users, but its main effect is on anxiety, not attention.
Are Semax and Selank approved anywhere?
Both are prescription nasal drugs in Russia. Neither is approved by the FDA or EMA, and nearly all the human data is Russian, small and not independently replicated.
How fast do Semax and Selank work?
Both are felt within about 15 to 30 minutes of a nasal dose and last a few hours. Blood levels fall within minutes; the effects outlast the peptide because they act on gene expression and neurotransmitter systems. Some Semax users report the effect fading with daily use.
Related reading
Daytime focus with lower anxiety
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Sources
- Comparative study of Selank and phenazepam in patients with anxiety disorders. Zhurnal Nevrologii i Psikhiatrii, 2014
- Semax, an analog of ACTH(4-10), induces BDNF expression and increases TrkB levels in rat hippocampus. Brain Research, 2006