Semax Dosage: Nasal vs. Injectable, What’s Studied
Semax is a synthetic ACTH fragment developed in Russia in the 1980s, where it's registered as a prescription nootropic and neuroprotective drug delivered as nasal drops. Published Russian trials, one comparing 30 acute stroke patients on Semax against 80 on standard therapy, another following 110 more patients on a specific 6,000 mcg/day protocol, report real clinical improvement. What's missing is any trial of the injectable form sold to buyers outside Russia: every study behind Semax's reputation used intranasal administration, not injection.
Reviewed by the PepGuard team · Last reviewed Jul 28, 2026
Synthetic heptapeptide, an analog of ACTH(4-7) with an added Pro-Gly-Pro tail (Met-Glu-His-Phe-Pro-Gly-Pro) · also referred to as ACTH(4-10) analog, MEHFPGP
Photo: Jame Gathany / UnsplashRegistered nasal drops, and an unstudied injectable.
In Russia, Semax is a registered prescription drug sold as nasal drops. Every clinical trial behind its reputation, stroke recovery, cerebrovascular insufficiency, a brain-imaging study in healthy volunteers, used that same intranasal route. Outside Russia, research-peptide vendors also sell Semax as a lyophilized powder meant to be reconstituted and injected. That’s a different product in every way that matters for evidence: no published human trial, at any dose, has ever tested Semax delivered by injection.
If a page tells you an injectable Semax dose was “clinically studied,” ask which trial, because we couldn’t find one. The dosage chart below keeps the registered route and the vendor-only route in separate rows on purpose.
What’s actually been dosed, and to whom.
| What's cited | Range |
|---|---|
| Registered stroke-recovery dose (Gusev et al. 2018, n=110, intranasal) | 6,000 mcg/day, two 10-day courses separated by a 20-day interval |
| Earlier cerebrovascular-insufficiency trial (Gusev et al. 2005, n=187, intranasal) | exact daily dose not specified in the available abstract; same registered route as above |
| Commonly cited nootropic dose (vendor/community, intranasal, no disease-specific trial behind this use) | 200-600 mcg/day, split into 2-3 doses |
| Commonly cited injectable dose (vendor-reported, zero human trials use this route) | 300-600 mcg/day, subcutaneous |
The only dose with a specific published clinical figure behind it is the intranasal 6,000 mcg/day regimen used in a 2018 stroke-recovery trial (two 10-day courses, separated by a 20-day interval, n=110). An earlier, larger Russian trial (n=187, 2005) followed a similar route and reported clinical benefit but didn't publish an exact daily microgram figure in the abstract available to us, so we're not inventing one. The nootropic and injectable doses that circulate in vendor and community protocols aren't drawn from either of these trials, they're separate, unvalidated conventions, and the injectable route in particular has never been tested in a single published human study.
A real drug that was never a powder.
Searches for “Semax dosage and reconstitution” assume Semax normally ships as a lyophilized powder that needs bacteriostatic water, the way many injectable research peptides do. The actual registered product never has: it’s sold and studied as ready-to-use nasal drops. The reconstitution step exists only because vendors chose to sell an injectable version, not because the clinical literature calls for one.
Mild and route-specific, in the studies that exist.
| Signal | Frequency | Context |
|---|---|---|
| Nasal irritation or mild burning at instillation | commonly reported | Consistent with intranasal drug delivery generally; the Russian clinical literature describes it as mild and transient. |
| Serious adverse events in the published stroke-recovery trials | rarely reported | The Gusev trials (100+ patients combined) reported clinical benefit without a distinct safety signal, but neither was designed or powered as a dedicated safety study the way an FDA Phase 3 program would be. |
| Jitteriness, agitation, or sleep disruption | occasionally reported | Anecdotal, from vendor and community sources describing off-label nootropic use, not measured in the published disease-outcome trials. |
| Effects of injectable administration | unknown / not studied | No completed human trial has tested Semax delivered by injection. Every study cited on this page used intranasal administration. |
| Long-term or cumulative effects of chronic nootropic use in healthy adults | unknown / not studied | The published trials were short courses (10-day blocks) in stroke or cerebrovascular-insufficiency patients, not healthy adults using it for sustained cognitive enhancement. |
Not FDA-approved. Registered as a prescription drug in Russia. FDA staff recommended against 503A compounding eligibility; the agency's advisory panel voted, by a narrow margin, to recommend it anyway.
Semax has never been approved by the FDA for any use. It has a real, decades-long regulatory history outside the US: Russian and secondary sources describe it as a registered prescription pharmaceutical, marketed as nasal drops, for indications including ischemic stroke recovery and cerebrovascular insufficiency. We could not independently verify the specific registration number against a primary Russian regulatory registry, only against sources repeating it, so treat that detail as unconfirmed even though the underlying clinical trial literature is real (see Sources). In the US, Semax was nominated for the FDA's 503A Category 2 list (bulk substances that raise significant safety risks) and was listed among withdrawn nominations before FDA staff evaluated it fresh for the Pharmacy Compounding Advisory Committee's July 23-24, 2026 meeting, specifically for potential use as a treatment for cerebral ischemia, migraine, and trigeminal neuralgia, not the cognitive-enhancement or nootropic use that drives most of today's search traffic. FDA staff recommended against adding it to the compounding list, citing immunogenicity risk and "no, or limited, safety-related information for proposed routes of administration." The advisory panel didn't follow that recommendation: per independent reporting from NPR and CBS News, it voted, by a narrow margin, in favor of adding Semax to the compounding-eligible list anyway, one of six peptides to receive a favorable vote that day. That's an advisory recommendation, not an FDA decision, the FDA is not required to follow it, though it typically does, and has not yet acted on it as of this writing. Check the committee's actual final outcome before trusting any claim about Semax's US legal status made after this update, including this one.
Every claim above, traced back.
Two Russian stroke-recovery trials, a mechanism study, a shared human brain-imaging study, and current FDA compounding records. Click through and check them yourself.
Semax questions, answered.
No. It's registered as a prescription drug in Russia, not the US. Semax was nominated for the FDA's 503A Category 2 list and is currently listed as a withdrawn nomination, with the agency citing limited safety-related information for its proposed routes of administration. It's now scheduled to come back in front of the FDA's advisory committee on July 23-24, 2026, for evaluation as a cerebral ischemia, migraine, and trigeminal neuralgia treatment, not for the nootropic use most searches are actually about.
It's the difference between a studied drug and an unstudied one. Every published human trial behind Semax, the stroke-recovery studies, the cerebrovascular-insufficiency trial, the healthy-volunteer brain-imaging study, used intranasal administration. The injectable Semax sold by some research-peptide vendors has never been tested in a single published human study, at any dose.
The one number with a real trial behind it is 6,000 mcg/day intranasally, given as two 10-day courses with a 20-day break, from a 2018 stroke-recovery study. The 200-600 mcg/day range that circulates in nootropic and vendor content is a separate, unvalidated convention, not drawn from that trial or any other disease-outcome study.
That's not what most of the evidence tested. Almost every published trial enrolled stroke or cerebrovascular-insufficiency patients, not healthy adults seeking a cognitive edge. The one study that scanned healthy volunteers (a 52-person resting-state fMRI trial) measured brain connectivity changes after dosing, not memory or focus performance, so it doesn't directly answer the question either.
Keep researching.
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