Semax
Also known as ACTH 4-10 analog
A synthetic peptide analog of ACTH(4-10) developed in Russia for neuroprotection and cognitive enhancement. Semax enhances memory, focus, and mental clarity while also offering neuroprotective effects after brain injury. It is one of the most studied nootropic peptides.
| Typical dose | 200-600 mcg |
|---|---|
| Frequency | Once to three times daily (nasal) |
| Half-life | ~5 minutes (rapid CNS distribution) |
| Cycle length | 2-4 weeks on, 2 weeks off |
| Research level | moderate |
| Prescription required | No |
Mechanism of action
Increases BDNF and NGF expression, modulates dopaminergic and serotonergic systems, enhances cerebral blood flow, and activates melanocortin receptors (MC3/MC4) without significant adrenocortical stimulation.
What this means in practice
Semax sits apart from most compounds here in that it's typically administered intranasally rather than injected, which changes the practical routine entirely — no reconstitution syringes, no injection sites to rotate. It's approved and prescribed in Russia for stroke and cognitive indications, which gives it a clinical history most research peptides lack, though that history is largely unavailable in English. It's frequently paired with Selank, on the logic that one leans stimulatory and the other anxiolytic.
Reported side effects
- Irritability (rare)
- Headache
- Nasal dryness
Commonly stacked with
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Get Optim on Google Play →This page is informational and summarises publicly available research. It is not medical advice, not a prescription, and not a recommendation to use any compound. Most compounds described here are not approved by the FDA for human use. Legal status varies by jurisdiction and is yours to determine. Talk to a qualified clinician before starting, stopping, or changing any protocol. For adults 18+. Optim does not sell, source, or recommend suppliers.