What is Semax?
Semax is a synthetic peptide based on a fragment of adrenocorticotropic hormone (ACTH), modified for stability. Developed in Russia, it’s been studied and used there for cognitive and neurological applications, including stroke recovery.
As with Selank, its evidence base is real but comes largely from Russian research with limited Western replication.1
Benefits & what it’s studied for
Its main studied use, for attention, memory, and mental performance.
Studied in Russia in stroke and ischemia contexts.
Investigated for effects on BDNF and stress-related signaling. We grade it Emerging given limited Western replication.
How does Semax work?
Semax is thought to act partly by increasing BDNF (brain-derived neurotrophic factor) and modulating neurotransmitter systems, supporting neuronal function and resilience. It’s typically administered intranasally.5
Dosing & administration
Research describes intranasal administration.6
This is educational, not medical advice. We don’t publish dosing. Specific dosing should be determined by a licensed provider after evaluation.
Risks, side effects & safety
limited long-term safety data outside Russian studies. Medical supervision is important given its experimental status.7
Legality & status
Semax was among peptides removed from Category 2 in April 2026 and is scheduled for PCAC review on July 24, 2026. Off Category 2 ≠ 503A-compoundable ≠ FDA-approved — three separate things, and the situation is moving. Confirm current status with a licensed provider.3 See the full picture in our legality explainer.
Regulatory status as of June 2026 — reconfirm against the live FDA 503A list before go-live.
Thinking about Semax?
Talk to a licensed provider who can tell you if it fits your goals — and build a safe protocol.
Research & references
- 1Semax / ACTH(4-10)-derivative research (Russian clinical literature). Link to be finalized. link pending
- 2Cognition / focus studies. Link to be finalized (largely Russian). link pending
- 3FDA — April 2026 Category 2 removal; PCAC July 24, 2026 docket; FDA-2025-N-6895. Confirm at publish. link pending
- 4Neuroprotection (stroke/ischemia) & BDNF studies. Link to be finalized. link pending
- 5Mechanism literature (BDNF, neurotransmitter systems). Link to be finalized. link pending
- 6Administration / dosing literature (intranasal). Link to be finalized. link pending
- 7Semax safety / tolerability literature. Link to be finalized. link pending
Reference links are illustrative placeholders — replace with verified PubMed/journal URLs before publishing.
Frequently asked questions
What is Semax used for?+
It’s studied mainly for cognition, focus, and neuroprotection.
Is Semax FDA-approved?+
No. It came off Category 2 in April 2026 and is under PCAC review in July 2026, but that’s not FDA approval.
How is Semax taken?+
Research describes intranasal administration; dosing should be set by a provider.
Semax vs Selank — what's the difference?+
Both are Russian-developed peptides; Semax skews toward cognition/neuroprotection, Selank toward anxiety/stress.
How strong is the evidence?+
Real but largely Russian and not broadly replicated in Western trials, so we grade it Emerging.