What it is
Semax is a synthetic peptide of seven amino acids, Met-Glu-His-Phe-Pro-Gly-Pro. The first four are positions 4 to 7 of adrenocorticotropic hormone (ACTH), the pituitary hormone best known for driving cortisol release. The last three, Pro-Gly-Pro, were added to slow its breakdown. Researchers often describe it as an analogue of ACTH (4-10).
It came out of the same Russian research programme that later produced Selank, and it is sold in Russia by Peptogen as nasal drops in two strengths: 0.1% for memory, attention and a range of neurological uses, and 1% for acute stroke and early recovery.
Outside Russia it has no approval from any major regulator, and nearly all of its research, clinical and animal, comes from Russian groups.
How it works
Short ACTH fragments have long interested researchers because they seemed to affect attention and learning in animals without acting on the adrenal glands. Semax keeps that brain-active segment and drops the part that drives cortisol.
The best-documented mechanism is on brain-derived neurotrophic factor (BDNF), a growth factor central to learning and to neuron survival:
- Dolotov and colleagues (2006) gave rats a single intranasal dose. Hippocampal BDNF protein rose up to 1.4-fold, activation of its receptor trkB rose 1.6-fold, and BDNF and trkB gene activity rose threefold and twofold. The rats also learned an avoidance task better.
Russian animal studies have also looked at other neurotransmitter and stress systems, but the BDNF work is the most cited.
What the research found
Animal studies
The animal work points in one direction: better learning in rodents and the BDNF and trkB changes above. Rat studies in a model of Parkinson-like damage have also been published. Most of this comes from a small number of Moscow laboratories.
Human studies
The human evidence comes from Russian clinical studies, published mainly in Russian-language journals.
- Gusev and colleagues (2018) randomised 110 people recovering from ischaemic stroke, in early (about three months after the stroke) or late (about seven months) rehabilitation, to Semax plus rehabilitation or rehabilitation alone, over five months. Blood BDNF rose quickly with Semax and stayed higher. Daily-living scores on the Barthel index improved faster in the first month with Semax. Patients who started rehabilitation early did better overall, even with equal or lower BDNF.
That study compared Semax with no added treatment rather than a placebo, and it measured BDNF in blood, not in the brain. It has not been repeated by a group outside Russia, and there is no large placebo-controlled Semax trial in English-language journals. Claims online about Semax and ADHD, depression or "focus" in healthy adults go well beyond what published human trials show.
Side effects reported in studies
The Russian literature describes Semax as well tolerated, but English-language abstracts rarely give side effect counts, so frequency figures you see online cannot be traced to a source. Nasal irritation is a plausible issue with any nasal drop. Because Semax is derived from ACTH, a hormone fragment, and influences dopamine systems in animals, long-term effects in healthy people are simply unknown.
Semax vs Selank
| Semax | Selank | |
|---|---|---|
| Built on | ACTH 4-7 | Tuftsin (immune peptide) |
| Developed for | Stroke, cognition | Anxiety, stress |
| Best-studied mechanism | BDNF and trkB in rats | GABA and enkephalin systems |
| Russian product | 0.1% and 1% nasal drops | 0.15% nasal drops |
For a full comparison see Semax vs Selank. Cerebrolysin is the other stroke-linked peptide product, with a much larger body of trials.
Status in the Philippines
No Semax product is registered with FDA Philippines, so it cannot be sold here as a medicine. It is not a controlled substance under RA 9165. Locally it is sold by research-chemical suppliers, usually as lyophilised powder rather than the finished Russian nasal drops, and it is popular in Manila's office and biohacker circles. Stroke in the Philippines is treated with registered medicines and rehabilitation; Semax is not part of Philippine stroke care.
Local stock Semax 10mg at Primara Labs, delivered in Metro Manila and nationwide. Research use only.
Storage
Lyophilised powder is best kept refrigerated and away from light. Once reconstituted, keep it at 2 to 8°C in the main body of the fridge, not the door, and plan around brownouts, which can push a household fridge out of range within hours. See the beginner guide for handling basics.
