Semax

Russian nootropic in the ACTH(4-7) family - rapid BDNF/NGF upregulation and calm cognitive enhancement without a stimulant profile.

Approved in RussiaResearch chemical (West)IntranasalNootropic

Key facts

Common routesIntranasal, SC

Half-life12–24 h effect

Typical range200–600 mcg

Summary

Semax is a synthetic heptapeptide derived from the ACTH(4-7) fragment, with a Pro-Gly-Pro extension at the C-terminus to protect against enzymatic degradation. Developed at the Russian Academy of Sciences' Institute of Molecular Genetics; approved in Russia for stroke recovery, cognitive impairment, and optic-nerve disease.

Effects last 12–24 hours per intranasal dose despite a short plasma half-life - the effect outlives circulation kinetics through BDNF / NGF signalling. Standard user effect: calm cognitive enhancement without stimulant jitter.

Mechanism notes

BDNF / NGF upregulation

Rapid increase of brain-derived neurotrophic factor and nerve growth factor in hippocampus and frontal cortex. Drives neuroplasticity and learning - explains why the effect outlives the rapid plasma clearance.

Dopamine / serotonin modulation

Increases dopamine and serotonin turnover, improving mood and motivation. Clean non-stimulant focus rather than wired alertness.

Melanocortin receptor interaction

Retains some affinity for melanocortin receptors from its ACTH ancestry - can influence attention and brain inflammation.

Dosing patterns

Nootropic use (intranasal)

0.1% solution intranasal, 200–600 mcg (1–3 sprays per nostril) morning. Onset 10–20 min. Standard biohacker strength; the Russian 1.0% preparation is the stroke dose.

Cycle discipline

14 days on / 14 days off is the standard community discipline against TrkB receptor downregulation from chronic BDNF elevation. Continuous use blunts the subjective effect over weeks.

Subcutaneous use (experimental)

600 mcg–1 mg daily SC for acute neuroprotection / stroke-recovery applications. Higher systemic bioavailability, but for standard nootropic use intranasal is the established route.

Evidence snapshot

Approved drug in Russia with decades of clinical use for stroke and ischaemia indications. Western research is limited to animal models, but the BDNF-upregulation and neuroprotection signals are consistent across studies.

Clinical data (Russia)

Multiple RCTs in ischaemic stroke show improved recovery vs standard care. Healthy-adult nootropic use evidence is thinner - predominantly animal models and community logs.

Western data

Animal models confirm BDNF upregulation and neuroprotection. No Western RCTs in healthy adults. Mechanism well-characterised, outcomes less so.

Safety considerations

One of the cleanest safety profiles in the catalogue: non-addictive, no withdrawal, no cardiovascular strain. The two things to track are hair shedding (anecdotal, reversible) and tolerance buildup from continuous use.

Common cautions

Anecdotal hair shedding / thinning (reversible on discontinuation)
Nasal irritation with frequent intranasal use
Tolerance buildup with continuous use - 14/14 cycling is the fix
Theoretical contraindication in seizure history; stimulant potentiation requires dose reduction when combined