Head-to-head
Semax vs Selank
A field-by-field comparison of Semax and Selank drawn from the PeptideIndex database: mechanism, evidence grade, half-life, administration route, reported dosing, side effects, storage and legal status. Both are indexed as cognitive compounds, so the useful question is how they differ within that category.
Semax vs Selank at a glance
| Attribute | Semax | Selank |
|---|---|---|
| Category | Cognitive | Cognitive |
| Evidence grade | Limited | Limited |
| Also known as | ACTH(4-10) analogue | Tuftsin analogue, TP-7 |
| Chain | Heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) | Heptapeptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro) |
| Mechanism | A non-hormonal ACTH fragment that raises BDNF and NGF expression in the hippocampus and modulates dopaminergic and serotonergic tone without corticotropic activity. | A synthetic analogue of the immunopeptide tuftsin. It modulates GABA-A expression, inhibits enkephalin degradation and shifts the balance of monoamine neurotransmitters, producing calm without benzodiazepine-like sedation. |
| Reported benefits | Increased BDNF signalling · Improved attention and mental stamina · Neuroprotective effects in ischaemia models | Anxiolytic effect without sedation or dependence · Improved stress resilience · Mild cognitive and immune modulation |
| Reported side effects | Nasal irritation · Overstimulation or irritability · Headache at higher doses | Nasal irritation · Occasional drowsiness · Rare mood flattening |
| Half-life | Minutes intranasally; central effects persist for hours | Short — dosed 1–3 times daily |
| Administration | Intranasal spray or drops | Intranasal spray |
| Dosing overview | 300–600 mcg daily, split doses, in 2–4 week cycles | 250–750 mcg daily in divided doses, 2–4 week cycles |
| Storage | Refrigerate the solution; discard per supplier guidance | Refrigerated solution, protected from light |
| Legal status | Approved medicine in Russia; unapproved elsewhere. | Registered in Russia; research-only status elsewhere. |
Key differences between Semax and Selank
Both are cognitive compounds
Semax and Selank are both indexed under cognitive, so they compete for the same use case rather than complementing each other. Semax: "A Russian nootropic peptide used clinically there for stroke recovery and cognitive impairment, popular as an intranasal focus aid." Selank: "An anxiolytic peptide developed alongside Semax, used for anxiety and stress without sedation or dependence."
Mechanism of action
Semax: A non-hormonal ACTH fragment that raises BDNF and NGF expression in the hippocampus and modulates dopaminergic and serotonergic tone without corticotropic activity. Selank: A synthetic analogue of the immunopeptide tuftsin. It modulates GABA-A expression, inhibits enkephalin degradation and shifts the balance of monoamine neurotransmitters, producing calm without benzodiazepine-like sedation.
Half-life and dosing frequency
Semax is listed at minutes intranasally; central effects persist for hours; Selank at short — dosed 1–3 times daily. That difference is what drives the reported schedules: 300–600 mcg daily, split doses, in 2–4 week cycles versus 250–750 mcg daily in divided doses, 2–4 week cycles
Route of administration
Semax is administered by intranasal spray or drops. Selank is administered by intranasal spray.
Legal and regulatory status differs
Semax: Approved medicine in Russia; unapproved elsewhere. Selank: Registered in Russia; research-only status elsewhere. This is usually the most practical difference between two compounds, because it determines whether a supply chain is labelled and regulated at all.
Handling and storage
Semax is stored refrigerate the solution; discard per supplier guidance. Selank is stored refrigerated solution, protected from light.
What Semax and Selank have in common
- Category: both listed as Cognitive
- Evidence grade: both listed as Limited
Both profiles list the same reported side effects: nasal irritation.
Each compound in brief
Semax
Cognitive · Limited evidence
A Russian nootropic peptide used clinically there for stroke recovery and cognitive impairment, popular as an intranasal focus aid.
Considerations: Nearly all clinical data is Russian-language · Effects are subtle and cumulative · Often cycled to avoid tolerance
Selank
Cognitive · Limited evidence
An anxiolytic peptide developed alongside Semax, used for anxiety and stress without sedation or dependence.
Considerations: Often paired with Semax for calm focus · Western clinical evidence is minimal · Effect size is modest
Related comparisons and reading
Every figure on this page is reproduced from the compound profiles in this database and reflects published literature and commonly reported protocols. It is educational information, not medical advice, and not a recommendation to use either compound. See the medical disclaimer.