Treatment
Semax: what it is and its status in 2026
Semax explained: the Russian ACTH(4-10) analog, what its stroke studies show and miss, the nasal spray under the HHS policy, and how it differs from Selank.
By Julian Caraulani · Updated October 30, 2026 · Reviewed by Dr. A. Goher, MBBS
Semax is a synthetic seven-amino-acid peptide modeled on a fragment of the hormone ACTH, developed and used as a medicine in Russia. Its human evidence is mostly small Russian stroke studies. Since 28 October 2026, an interim HHS policy lets licensed US pharmacies compound it for intranasal use only (HHS policy, archived copy). It is not FDA-approved.
Below: what Semax is, its status in Russia, what the human studies found and where they fall short, what the HHS policy allows, the nasal spray question, and how Semax differs from Selank. Policy facts were checked on 30 October 2026.
What Semax is
Semax is a heptapeptide (a chain of seven amino acids) with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. A 2007 paper describes it this way: "The heptapeptide Semax is an analogue of the N-terminal fragment (4-10) of adrenocorticotropic hormone, but is completely devoid of any hormonal activity" (Tsai 2007, PubMed 16996699). In plain terms, it borrows part of the ACTH structure without acting like ACTH on the adrenal glands. The last three amino acids (Pro-Gly-Pro) were added to slow its breakdown in the body.
Its developers summarized 15 years of work on it in 1997, calling it "one of the rare analogues of regulatory peptides which underwent all stages from fundamental investigations to practical usage" (Asmarin 1997, PubMed 9173745).
Is Semax a registered medicine in Russia?
Yes, according to peer-reviewed sources. A 2025 paper in Acta Naturae states that "Semax does not exhibit any hormonal activity and is included in the Russian List of" Vital and Essential Drugs for Medical Application, citing Russian Government Decree No. 2406-r of 12 October 2019 (Acta Naturae 2025, full text; PMC12755871). A 2026 orthopaedics review says it "has been used in Russia for a range of neurological conditions, including ischemic stroke and optic nerve injury" (JAAOS Global Research and Reviews 2026, full text; PMC12753158).
We could not read the Russian state register of medicines ourselves, so the registration detail rests on these papers. Russian approval does not carry over to the US, and no Semax product is FDA-approved.
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What the human studies show
Most clinical work on Semax was done in Russia, published in Russian, and led by groups linked to its development. The abstracts we could read on PubMed:
| Study | Who | What it reported | Limits |
|---|---|---|---|
| Gusev 1997 | 30 patients in the acute phase of ischemic stroke, compared with 80 on standard care | Semax had "some influence" on the rate of neurological recovery | Abstract does not describe randomization or blinding |
| Gusev 2005 | 187 patients with cerebrovascular insufficiency | Clinical improvement and fewer strokes or transient attacks reported | Russian-language; design details not in the abstract |
| Gusev 2018 | 110 patients in rehabilitation after ischemic stroke | Higher blood BDNF levels and better Barthel index scores with Semax | Subgroups with and without Semax; no placebo described |
| Polunin 2000 | Patients with optic nerve disease | Better visual function recovery when added to standard therapy | Small, Russian-language, no placebo described |
| Lebedeva 2018 | 24 healthy volunteers | Brain network changes on resting-state MRI after one intranasal use | Imaging marker, not a clinical outcome |
The 1997 study's own wording is cautious: adding Semax to intensive therapy "had some influence on the rate of restoration of the damaged neurological functions" (Gusev 1997, PubMed 11517472). The 2018 study concluded that Semax and early rehabilitation "increase BDNF plasma level, speed functional recovery, and improve motor performance" (Gusev 2018, PubMed 29798983).
What is missing: we found no Semax trial registered on ClinicalTrials.gov (searched 30 October 2026), no large randomized placebo-controlled trial published in English, and no independent replication outside the developer network. A Belgian public health lab wrote in 2020 that Semax and Selank, to the authors' knowledge, "have not completed any clinical trials" (Vanhee 2020, PubMed 31667971). Claims about focus, memory or mood in healthy people go well beyond what these studies tested.
Side effects and safety
The Russian studies report few problems. The 2005 cerebrovascular study described Semax as having a "minor percent of side-effects" and being "well tolerated by patients, including those of older age groups" (Gusev 2005, PubMed 15792140). HHS, summarizing the record FDA reviewers compiled, wrote that "the intranasal human record CDER itself compiled covers several hundred subjects with no reported adverse outcome" (HHS policy, archived copy).
FDA's own reviewers were less confident. Before the April 2026 changes, FDA wrote that "FDA has no, or limited, safety-related information for proposed routes of administration" for Semax (FDA). HHS notes FDA reviewers had raised bleeding and abuse-potential concerns, and states "the bleeding and abuse-potential signals have no clinical counterpart in that record" (HHS policy, archived copy). Tell your prescriber about bleeding disorders, blood thinners and any history of substance use.
Semax under the HHS policy
The HHS enforcement-discretion policy, announced in the Federal Register on 30 October 2026, lists six peptides in its Appendix A: BPC-157, Epitalon, KPV, MOTS-c, Semax and TB-500. For Semax, the route is narrow: "enforcement discretion for semax free base is appropriate for intranasal use" when made from an ingredient with a qualifying certificate of analysis (HHS policy, archived copy). Injectable Semax falls outside the policy.
Three points about what the policy is and is not:
- It is not approval. The notice states "Compounded drugs are not FDA-approved, which means FDA does not review their safety, effectiveness, or quality before they are marketed" (Federal Register).
- It is interim. HHS "may revisit application of this interim policy (in whole or in part) if, among other things, a safety signal or product quality issue arises" (Federal Register).
- It requires a patient-specific prescription, a single active ingredient per product, and serious adverse event reporting to FDA. State pharmacy rules still apply.
Our HHS peptide policy guide and peptide legal status tracker cover the conditions in full.
Semax nasal spray
Because intranasal use is the only covered route, any prescription Semax product in the US will be a nasal product. Superpower lists a "Semax Nasal Spray" under brain health on its peptides page, as a waitlist item with no price shown (Superpower). We found no other prescription program listing it on 30 October 2026; see all programs we track.
One open question: the policy's device condition reads "The only drug delivery device co-packaged or containing the compounded drug is an FDA 510(k)-cleared syringe" (HHS policy, archived copy). The text does not say how that applies to a nasal spray pump. Ask the program and its pharmacy how the product is packaged.
Semax vs Selank
Selank is often mentioned in the same breath, but its status is different.
| Semax | Selank | |
|---|---|---|
| What it is | Analog of an ACTH fragment | Synthetic heptapeptide based on tuftsin, an immune peptide |
| Status in Russia | On the Russian essential drugs list | Described as "approved in Russia for the treatment of anxiety" (JAAOS GRR 2026) |
| HHS interim policy | Covered, intranasal only | Not covered: not in Appendix A |
| FDA approval | None | None |
| Prescription programs we track | Superpower waitlist (nasal spray) | None |
FDA's compounding page lists selank acetate among substances whose nominations were withdrawn, and says "FDA lacks important information regarding any safety issues raised by selank acetate administered to humans" (FDA). Leaving that list does not make a peptide compoundable: HHS says of Semax that "neither the placement nor the removal changed its status under section 503A" (HHS policy, archived copy). Selank sold online is generally labeled research use only, which this site does not cover; see research vs prescription peptides.
FAQ
What is Semax?
Semax is a synthetic peptide of seven amino acids, built from part of the hormone ACTH plus three added amino acids that slow its breakdown. Russian researchers developed it, and it is used in Russia for stroke and other neurological conditions. Published reviews describe it as lacking ACTH's hormonal activity. No Semax product is FDA-approved in the United States.
Is Semax legal in the US in 2026?
Licensed 503A pharmacies may compound Semax for intranasal use under HHS's interim enforcement-discretion policy dated 28 October 2026, with a patient-specific prescription. That is not FDA approval, and HHS can withdraw or narrow the policy. Injectable Semax and multi-peptide blends fall outside it, and state pharmacy rules still apply. Checked 30 October 2026.
Does Semax work?
Evidence is limited. Russian studies in stroke, cerebrovascular disease and optic nerve disease reported benefits, but they were small, mostly in Russian, and the abstracts do not describe placebo control or blinding. We found no registered trial on ClinicalTrials.gov. Claims about focus or memory in healthy people are not supported by trials of that use.
Is the Semax nasal spray covered by the HHS policy?
Intranasal Semax free base is the only route the policy covers, so a compounded nasal product is within scope if every other condition is met. The policy's device rule mentions only 510(k)-cleared syringes, and the text does not explain how nasal spray pumps fit. Ask the pharmacy how its product is packaged and labeled.
What is the difference between Semax and Selank?
Semax is modeled on an ACTH fragment and is mostly studied for stroke and cognition. Selank is based on tuftsin, an immune peptide, and is described as an anti-anxiety drug in Russia. Semax is covered by the HHS interim policy for intranasal use. Selank is not covered at all.
Where can I get a Semax prescription?
Superpower lists a Semax nasal spray on a waitlist with no price as of 30 October 2026. We found no other prescription program offering it yet. A licensed clinician must evaluate you first. Products sold as research use only are not prescriptions and are not covered by the HHS policy.
Compare licensed programs for the HHS-covered peptides on our best peptide programs page, or see every listed plan on the price table.