Semax
Met-Glu-His-Phe-Pro-Gly-Pro
A Russian-registered nootropic peptide studied for stroke recovery and cognition
Semax is a heptapeptide developed in Russia as an analog of a fragment of adrenocorticotropic hormone (ACTH 4-10). It is registered as a drug in Russia (nasal drops) and was first studied for stroke and other circulatory disorders of the brain; today it's marketed mainly as a nootropic. As of October 2026, it isn't approved in the US or EU. FDA reviewers found insufficient evidence of effectiveness, but an FDA advisory committee voted 8-5-1 in July 2026 to add it to the 503A compounding list; FDA hasn't acted on that vote. Unlike its parent hormone, Semax is reported to have no hormonal activity.
Read the research profile for mechanisms, citations, and safety context before comparing vendors. View the Semax research profile.
Key Benefits
Mechanism of Action
In rat studies, Semax raised levels of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the brain. Rodent studies also show effects on serotonin signaling. Given alone, it didn't change dopamine levels in mice, but it amplified amphetamine's effect on dopamine release. In rat stroke models, it reduced inflammation-related gene activity and showed antioxidant effects. A 2018 Russian study of 110 stroke patients reported higher blood BDNF with Semax. No published study has measured how it is absorbed or cleared in people.
Dosing Guidelines
Typical Dose
200-1000 mcg/day
Frequency
1-3x daily
Duration
10-14 days, followed by a 1-2 week break
Note: These figures reflect what users and vendors commonly report for nasal drops or spray; the cycle length comes from community and vendor guidance, not trials. Russian stroke studies used much higher doses: 12-18 mg/day for 5-10 days in a 1997 study, and two 10-day courses of 6,000 mcg/day in a 2018 study.
Research & Studies
Covers the mechanism, the rodent and human evidence, user-reported dosing and regulatory status of the nootropic peptide Semax.
Read Full ResearchHow Semax raised BDNF and NGF levels in rat brain studies, and what that may or may not mean for learning and memory in people.
Read Full ResearchA look at the small, mostly unblinded Russian stroke studies behind Semax and why FDA reviewers found the evidence insufficient in 2026.
Read Full ResearchPotential Side Effects
Reported side effects may include:
- - Limited human safety data (FDA review, 2026)
- - Nasal irritation or dryness from the spray (user reports; most common)
- - Mild headache (user reports)
- - Increased anxiety or irritability, mostly at higher doses (user reports)
- - Temporary hair shedding (rare anecdotal reports; not traced to a study)
- - Slight, transient increase in blood pressure (vendor lists; not traced to a study)
- - Overstimulation or poor sleep if taken late in the day (user reports)
- - Possible bleeding risk (concern raised by FDA reviewers)
This information is for research purposes only. Always consult with a healthcare professional.
Popular Stacking Options
Semax + Selank
The pairing users mention most. Users describe Selank's reported calming effect as offsetting Semax's stimulating one. No study has tested them together.
Shop this stackSemax + BPC-157
Some users combine them for brain-injury goals. BPC-157's evidence here comes from animal studies, and the pair hasn't been studied.
Shop this stackSemax + GHK-Cu
Some users add GHK-Cu, citing animal and cell data on nerve outgrowth. The pair hasn't been studied.
Shop this stackFrequently Asked Questions
Is Semax a stimulant like Adderall?
Not in the classical sense. Semax isn't an amphetamine, and Adderall is a prescription medicine. Users often describe Semax as stimulating but 'cleaner' and less jittery, without a crash; no study has compared the two. In mice, Semax amplified amphetamine's effect on dopamine release, which FDA reviewers called concerning in 2026.
How is Semax administered?
Semax is registered in Russia as nasal drops, and most users take it as a spray or drops. In rats, more of the dose reached the brain by the nasal route than by intravenous injection; this hasn't been measured in people. Vendors usually sell a lyophilized powder that users reconstitute with bacteriostatic water, or a pre-made solution, which users say often lacks a clear dose per spray.
Can I use Semax every day long-term?
Long-term daily use hasn't been studied in people. Russian stroke studies used short courses of 5-10 days. Users and vendors commonly describe 10-14 days on and a 1-2 week break, and forum guides say this prevents receptor downregulation, though no study has measured tolerance in people. Anyone considering use should speak with a healthcare professional.
What's the difference between Semax, N-Acetyl Semax, and N-Acetyl Semax Amidate?
These are modified versions that vendors market as more stable and potent. N-Acetyl Semax has an acetyl group added, and the Amidate version adds a further modification. We found no independent data comparing them with standard Semax, which is the only form with published research behind it.
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