Semax
ACTH 4–10 Analog (Cognitive Nasal Peptide)
Also known as: Met-Glu-His-Phe-Pro-Gly-Pro (ACTH 4–10 analog with C-terminal Pro-Gly-Pro)
Last updated May 4, 2026
What is Semax?
A nasal peptide prescribed in Russia since 2011 for cognitive enhancement and stroke recovery — no injection required. Most of the research is published in Russian, the U.S. regulatory status is complicated and the biohacking forums can’t agree. Here’s what the evidence actually shows.
Semax is a synthetic peptide derived from ACTH (adrenocorticotropic hormone), specifically the 4–10 fragment with an added Pro-Gly-Pro tail for stability. It modulates dopamine and serotonin systems and upregulates BDNF (brain-derived neurotrophic factor) — the protein responsible for neuroplasticity and new neural connections. Administered as a nasal spray, no injection required. Approved as a pharmaceutical in Russia for cognitive enhancement, stroke recovery and optic nerve disease.
What Does the Research Actually Show?
Russian clinical use since 2011 for attention, memory and mental performance. Human studies show improved attention metrics and measurable cognitive gains. The primary mechanism underlying these effects is BDNF (brain-derived neurotrophic factor) upregulation, documented in both human and animal studies. BDNF is a key mediator of neuroplasticity, learning and memory formation — Semax’s ability to increase BDNF levels is the most mechanistically supported explanation for the observed cognitive benefits. Most research published in Russian journals.
Used clinically in Russia for ischemic stroke. Studies show neuroprotective effects and improved recovery outcomes.
Without Western controlled human trials, we can’t fully verify that the practitioner-reported benefits hold up to peer-reviewed scrutiny. The Russian clinical track record is real, but “approved in Russia” is not the same as “proven by Western RCT standards.”
How Is Semax Administered?
| Route | Nasal spray (no injection) |
| Dosage range | 200–600 mcg/day |
| Frequency | 1–2 times daily, typically morning |
| Protocol | Time-limited courses with breaks; specific cycle lengths vary widely between providers |
| Access | Approved as a pharmaceutical in Russia; not FDA-approved in the U.S.; obtained via compounding pharmacies or international sources |
What Are the Side Effects and Risks?
- Nasal irritation — the most commonly reported side effect.
- Headache — uncommon.
- Hair shedding reported anecdotally at higher doses.
Who Should NOT Use Semax?
If you are on MAOIs or other catecholamine-affecting medications: Semax modulates dopamine and serotonin systems. Combining it with MAOIs or other medications that affect catecholamine levels has not been studied and creates an unpredictable interaction profile. Your prescribing psychiatrist must be involved before adding Semax.
If you have a history of mania or bipolar disorder: BDNF upregulation and dopaminergic stimulation may theoretically trigger manic episodes in susceptible individuals. The interaction is not well-studied, but the mechanism is plausible enough that anyone with a bipolar diagnosis should not start Semax without psychiatric oversight.
If you are pregnant or breastfeeding: No safety data exists in pregnant or lactating populations. Absolute contraindication.
If you have an active seizure disorder: A lowered seizure threshold is theoretically possible with neuroactive peptides that modulate neurotransmitter systems. There is no documented case linking Semax to seizures, but anyone with epilepsy or a seizure history should not start without their neurologist’s involvement.
Before You Start: Get Baseline Labs
We recommend baseline lab work before starting any peptide protocol so you and your provider can track changes. Key markers include CBC, CMP, thyroid panel and a baseline cognitive or mood assessment with your provider.
Ask your provider about ordering these labs, or search for direct-to-consumer lab testing services in your area.
Order at-home labs from Everlywell →Lab recommendations are the same regardless of which service you use.
What You'll Need
If your provider prescribes an injectable protocol, you'll need basic supplies.
- Bacteriostatic Water (30ml)Link coming soon
- Insulin Syringes 29 gauge (100ct)Link coming soon
- Alcohol Prep Pads (200ct)Link coming soon
- Sharps ContainerLink coming soon
Supply links are affiliate links. We may earn a commission at no cost to you. We only link to commodity supplies, never to peptide products.
- 1Given that most Semax research is from Russian literature, how do you evaluate the evidence for prescribing it?
- 2What dosage and cycle length do you recommend for my specific cognitive concerns?
- 3Can Semax interact with any medications I’m currently taking, particularly SSRIs or stimulants?
- 4How will we measure whether it’s working — subjective assessment or cognitive testing?
- 5Where do you source your Semax, and can it be legally compounded right now?
- 6Would you recommend Semax alone or combined with Selank?
Is Semax Legal in 2026?
Not FDA-approved. Removed from Category 2 effective April 22, 2026. PCAC review scheduled for July 24, 2026 — Semax is on the agenda alongside DSIP and Epitalon. Compounding cannot resume until after PCAC review and a final FDA determination adds Semax to the 503A bulks list. If approved, it will be available via prescription through licensed compounding pharmacies — it will NOT be available over the counter or FDA-approved in the US.
Semax is approved as a pharmaceutical in Russia and has been used clinically there since 2011 — meaningfully different from gray-market sourcing, but separate from US regulatory status.
The FDA accepts public comments through Docket FDA-2025-N-6895. Comments received by July 9, 2026 will be provided to the committee.
How Do I Get Semax Through a Legitimate Provider?
No verified providers currently meet our evaluation criteria for this compound. Subscribe to be notified when that changes.
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