Semax
Molecular Identifiers
Overview
Nootropic peptide derived from ACTH (4-10) with a Pro-Gly-Pro addition. Improves focus and cognitive function. BDNF upregulation.
Interest in Semax centers on its nootropic profile — improvement of focus, attention, and cognitive performance under stress — without relevant hormonal properties of the original ACTH. It upregulates BDNF, modulates dopamine and serotonin, and has neuroprotective and anti-inflammatory effects in the CNS. It is also studied in ischemic stroke, post-trauma cognitive deficits, and mental fatigue.
In Brazil and most of the Western world it has no drug approval; it is prescribed off-label through compounding pharmacies in nasal or subcutaneous formulation. In Russia it is registered as a neurological drug (Semax nasal drops), included in the essential medicines list. Typical protocols last 4-8 weeks, with administration 1-2 times per day.
It was developed by the Institute of Molecular Genetics of the Russian Academy of Sciences, derived from fragment 4-10 of adrenocorticotropic hormone (ACTH) with a Pro-Gly-Pro extension added for enzymatic stability — abolishing the hormonal activity of ACTH while preserving its behavioral and neurotrophic effects.
Among peptide nootropics, Semax is the "pro-cognitive sibling" of Selank — same Russian developing group, same Pro-Gly-Pro strategy — focused on attention and focus rather than on the anxiolytic axis. It differs from Cerebrolysin (a porcine mixture, not a single peptide) by being a defined sequence, and from investigational candidates such as Dihexa (HGF/c-Met, very potent synaptogenesis), P21 (BDNF + anti-tau, Alzheimer focus), and PE 22-28 (TREK-1, depression) by having a consolidated registration (Russia) and established clinical use in ischemic stroke.
MEHFPGP Met-Glu-His-Phe-Pro-Gly-Pro Half-life
~3-5 minutes
Administration Route
Intranasal or subcutaneous
Category
Cognitive & Neuroprotective
Mechanism of Action
- BDNF (brain-derived neurotrophic factor) upregulation
- Dopamine and serotonin modulation
- Neuroprotective effect
- Improvement of synaptic plasticity
- Anti-inflammatory action in the CNS
Dosage Protocol
Data compiled from the literature. This does not constitute medical advice.
| Parameter | Value |
|---|---|
| Dose | 300-600 mcg per injection |
| Frequency | 1-2 times daily |
| Timing | Morning and/or afternoon |
| Duration | 4-8 weeks |
Reported Side Effects
Adverse effects described in the literature. Severity and frequency vary between individuals.
- Mild nasal irritation (intranasal)
- Headache (rare)
Product Properties
| Purity | >98% |
| Appearance | White lyophilized powder |
| Solubility | Soluble in water and bacteriostatic water |
| Source | Solid-phase peptide synthesis (SPPS) |
| Storage | Lyophilized: -20°C for up to 2 years, 2-8°C for up to 6 months. Reconstituted: 2-8°C for up to 4 weeks. Protect from light and moisture. Avoid repeated freeze-thaw cycles. |
Presentations & Preparation
Vials of Semax found in the research market:
Reconstitution
- Diluent: Bacteriostatic water
- Volume: 2 ml per vial
- Slowly inject the diluent against the vial wall
- Gently swirl until fully dissolved
- Also available in nasal formulation
Storage
- Lyophilized: Refrigerated 2-8°C
- Reconstituted: Refrigerated 2-8°C (up to 30 days)
- Protect from direct light
- Do not freeze after reconstitution
Scientific Studies
Published studies on Semax.
Semax, a synthetic analog of ACTH(4-10) with nootropic properties: a review
Ashmarin IP, Nezavibat'ko VN, Levitskaia NG, Koshelev VB, Kamensky AA
Neuroprotective and nootropic drug Semax in the treatment of patients with cerebrovascular disease
Gusev EI, Skvortsova VI, Chukanova EI, et al.
Related Peptides
Adamax
100-500 mcg via intranasal or subcutaneous · 1-2 times daily
Cerebrolysin
5-30 ml per injection · Once daily
Cortagen
Dihexa
DSIP
100-300 mcg per subcutaneous injection · Once daily
Epithalon
1-5 mg per subcutaneous injection (some protocols use 5-10 mg per full cycle) · Once daily or every other day