The short answer
Both are used as nasal sprays and approved in Russia, with opposite jobs: Selank, a tuftsin analogue, eased anxiety without sedation in small Russian trials, while Semax, derived from ACTH, raises BDNF in rats and is approved there for stroke recovery. They’re a classic pair: Semax for drive, Selank for calm.
Side by side
| Compared | Selank | Semax |
|---|---|---|
| Category | Cognitive | Cognitive |
| Also known as | Tuftsin analogue, TP-7 | ACTH 4-7 Pro8Gly9Pro10, N-acetyl Semax |
| What it is | A synthetic peptide based on tuftsin, an immune molecule your spleen naturally produces. | A nasal spray nootropic derived from ACTH but modified to remove hormonal effects. |
| How it works | Synthetic analogue of the immunomodulatory peptide Tuftsin. Its anxiolytic and nootropic effects run through GABA and serotonin systems (rat studies). Reduced anxiety without sedation in small Russian trials; memory and learning gains come from rodent studies. | Synthetic heptapeptide derived from ACTH. In rats it raises BDNF and NGF expression, lifts serotonin turnover and amplifies stimulated dopamine release, which supports cognition, focus and neuroprotection. Used clinically in Russia for stroke recovery. |
| Commonly reported | Calmer and less socially tense without feeling sedated, subtle effects for some, and mild tiredness at higher doses. Approved as an anxiety medication in Russia. | A quick lift in focus, alertness and mental energy within minutes to an hour, nasal stinging, and irritability or poor sleep at high doses or late in the day. Approved in Russia for stroke recovery and memory problems after brain injury. Often paired with Selank — Semax for drive, Selank for calm. |
| Studied range | Research range: 250–500 mcg. Studied in research — not a recommendation. | Research range: 200–900 mcg. Studied in research — not a recommendation. |
| How often | Daily | Daily |
| Half-life | ~10 min in blood; nasal effect longer | Very short (~minutes); CNS effects persist longer |
| Route | Nasal spray, SubQ injection | Nasal spray |
| Typical run | 2–4 week cycles typical. Can repeat with breaks. Tolerance generally low. | 2–4 week cycles. Some use daily long-term without noted issues. Cycling still advised. |
| Evidence | Moderate: animal studies + some human data | Moderate: animal studies + some human data |
| Common side effects | Mild nasal irritation, fatigue, slight dizziness | Nasal irritation, headache, anxiety, increased energy (can disrupt sleep) |
- Category
- SelankCognitive
- SemaxCognitive
- Also known as
- SelankTuftsin analogue, TP-7
- SemaxACTH 4-7 Pro8Gly9Pro10, N-acetyl Semax
- What it is
- SelankA synthetic peptide based on tuftsin, an immune molecule your spleen naturally produces.
- SemaxA nasal spray nootropic derived from ACTH but modified to remove hormonal effects.
- How it works
- SelankSynthetic analogue of the immunomodulatory peptide Tuftsin. Its anxiolytic and nootropic effects run through GABA and serotonin systems (rat studies). Reduced anxiety without sedation in small Russian trials; memory and learning gains come from rodent studies.
- SemaxSynthetic heptapeptide derived from ACTH. In rats it raises BDNF and NGF expression, lifts serotonin turnover and amplifies stimulated dopamine release, which supports cognition, focus and neuroprotection. Used clinically in Russia for stroke recovery.
- Commonly reported
- SelankCalmer and less socially tense without feeling sedated, subtle effects for some, and mild tiredness at higher doses. Approved as an anxiety medication in Russia.
- SemaxA quick lift in focus, alertness and mental energy within minutes to an hour, nasal stinging, and irritability or poor sleep at high doses or late in the day. Approved in Russia for stroke recovery and memory problems after brain injury. Often paired with Selank — Semax for drive, Selank for calm.
- Studied range
- SelankResearch range: 250–500 mcg. Studied in research — not a recommendation.
- SemaxResearch range: 200–900 mcg. Studied in research — not a recommendation.
- How often
- SelankDaily
- SemaxDaily
- Half-life
- Selank~10 min in blood; nasal effect longer
- SemaxVery short (~minutes); CNS effects persist longer
- Route
- SelankNasal spray, SubQ injection
- SemaxNasal spray
- Typical run
- Selank2–4 week cycles typical. Can repeat with breaks. Tolerance generally low.
- Semax2–4 week cycles. Some use daily long-term without noted issues. Cycling still advised.
- Evidence
- SelankModerate: animal studies + some human data
- SemaxModerate: animal studies + some human data
- Common side effects
- SelankMild nasal irritation, fatigue, slight dizziness
- SemaxNasal irritation, headache, anxiety, increased energy (can disrupt sleep)
Typical run: Community practice — opinions vary. Not a clinical recommendation.
Week by week
Each entry’s cards by day window, as the compound pages show them. Day 1 is the day you start it.
Selank
- Day 1–3 Calm without the fog
- Day 3–7 Stress resilience is building
- Day 7–14 Memory and focus sharpening
- Day 14–28 Where the Russian courses stop
Semax
- Day 1–3 Focus snaps into place
- Day 3–7 Each dose builds on the last
- Day 7–14 Learning speed is up
- Day 14–28 The end of a typical cycle
Together or one or the other
Selank and semax are a common stack: each lists the other among its common stacks, and they’re together in the Limitless stack.
- Limitless: Cognitive enhancement & neuroprotection stack (Semax, Selank and Dihexa).
Community · Selank
The classic nootropic pair
Selank for calm and Semax for drive — different mechanisms, complementary effects. Selank lowers your anxiety floor while Semax raises your cognitive ceiling. Commonly reported: many users who try them separately end up running both.
Community · Semax
Drive meets calm
The Semax + Selank stack is a community classic. Commonly reported: Semax delivers the focus and motivation while Selank smooths the edges and keeps anxiety from spiking. Together they cover both sides of cognitive performance.
Questions people ask
How long do selank and semax last?
The half-life of selank is ~10 min in blood; nasal effect longer. The half-life of semax is very short (~minutes); CNS effects persist longer.
How often are selank and semax taken?
Selank: daily. Routes: Nasal spray, subQ injection. Semax: daily. Route: Nasal spray.
How are selank and semax dosed in research?
The research range for selank is 250–500 mcg. The research range for semax is 200–900 mcg. Studied in research — not a recommendation.
What are the common side effects of selank and semax?
For selank, the library lists: mild nasal irritation, fatigue, slight dizziness. For semax: nasal irritation, headache, anxiety, increased energy (can disrupt sleep).
Are selank and semax taken together?
Selank and semax are a common stack: each lists the other among its common stacks, and they’re together in the Limitless stack. Selank for calm and Semax for drive — different mechanisms, complementary effects. Selank lowers your anxiety floor while Semax raises your cognitive ceiling. Commonly reported: many users who try them separately end up running both.
Each one in full
PepVault for iPhone
Track either one in PepVault
Log every dose of selank or semax, with reminders on your schedule. 7 days free on the yearly plan for new subscribers.
