Semax Nasal Spray: Evidence, Safety and Why HHS Allows Only the Intranasal Route

Semax nasal spray is the form behind nearly all of the drug's human research. Semax is a seven-amino-acid peptide (Met-Glu-His-Phe-Pro-Gly-Pro) developed in Russia, and almost every human study of it gave it into the nose as drops or a 1% solution^[5][6][8]. Under a draft HHS enforcement policy announced October 28, 2026, HHS says it does not intend to take action against 503A pharmacies and physicians that compound semax under ten conditions, and the policy limits semax to intranasal use only^[1]. The policy is not final and is not binding on HHS or the public, and comments are open until November 13, 2026^[11]. One open question: the policy's device condition names only a 510(k)-cleared syringe and does not mention nasal spray pumps. That makes injectable semax, and semax-plus-selank combination sprays, fall outside the policy. This article covers why the nose is the route, what the small human studies of nasal semax found, what is still unknown about safety, and how a compounded spray differs from a “research use only” bottle. It does not recommend a dose, and semax is not FDA-approved for anything.

The short answer

• The nasal route is the one with human data. The Russian clinical studies of semax used nasal drops or an intranasal 1% solution^[5][6][7]. Injectable semax sold online as a powder has essentially no human record behind it.
• The draft HHS policy matches that. Appendix B of the policy says enforcement discretion for semax free base “is appropriate for intranasal use”^[1]. Injection is not covered, and the device condition does not mention spray pumps.
• Combination semax and selank sprays are not covered. The policy requires a single active ingredient, and selank is not one of the six Appendix A peptides^[1].
• The human evidence is thin. It comes from small studies in patients with stroke, motor neuron disease and optic-nerve disease, published mostly in Russian journals, plus one brain-imaging study in 24 healthy volunteers^[5][6][7][8]. None tested semax spray as a focus or memory aid in healthy people, which is how it is sold in the US.
• Short-term tolerability looks unremarkable; long-term safety is unknown. HHS describes the intranasal human record as several hundred subjects with no reported adverse outcome^[1]. Those were short courses in patients, not years of daily use.

Why semax is a nasal drug in the first place

Semax is an analog of a fragment of adrenocorticotropic hormone (ACTH), with a Pro-Gly-Pro tail at the end; its developers describe it as an ACTH(4-10) analog with prolonged activity^[2][4]. It is still a small peptide, and small peptides are broken down quickly by enzymes in blood and tissue. The nasal route is a way to reach the brain fast before that happens.

The best direct look at this comes from a Russian rat study that labeled semax with tritium and gave it intranasally at 50 micrograms per kilogram. Two minutes after dosing, 0.093% of the total radioactivity per gram was found in the brain, and 80% of that radioactivity was intact semax; the rest was metabolites. The peptide was degraded quickly, with the Pro-Gly-Pro fragment predominating in the samples^[2]. A later study from the same group exposed semax to enzymes from nasal mucus, brain membranes and rat blood and found it broke down to His-Phe-Pro-Gly-Pro^[3]. So some semax reaches the brain intact within minutes, but a nasal spray is not a sealed delivery system: part of each dose is cleared or digested in the nose and bloodstream.

Route also changed what semax did in animals. In rats, intranasal semax improved learning in a passive avoidance task at lower doses than intraperitoneal injection did, but intranasal semax did not change pain sensitivity, while intraperitoneal semax did^[4]. The authors read this as different brain pathways for the two effects. For a reader, the takeaway is narrower: results from one route do not carry over automatically to another, and the cognitive claims made for semax come from nasal dosing.

What the human studies of nasal semax found

Every study below is Russian, and most are small, open-label or add-on designs. The abstracts are the source for each number; several full texts are in Russian only.

Read together, these studies say semax has been given to a few hundred Russian patients, mostly by the nasal route and often in short courses, and that the reports are mostly favorable. They do not establish benefit to the standard US regulators use: there is no large, randomized, placebo-controlled trial, no replication outside Russia, and no trial of semax spray as a cognitive enhancer in healthy adults. The one study in healthy people measured brain activity on a scan, not memory or focus^[8]. Our semax evidence review covers the rodent BDNF work behind the nootropic claims.

What the draft HHS policy says about semax spray

Based on the identified updated information, enforcement discretion for semax free base is appropriate for intranasal use that is compounded from API accompanied by a CoA meeting the conditions of this policy.

— HHS 503A peptide policy, Appendix B (October 2026)

The policy is a draft statement of enforcement discretion, not approval. It says compounded drugs “are not FDA-approved, which means FDA does not review their safety, effectiveness, or quality before they are marketed,” and that HHS may revisit the policy if a safety signal or product quality issue arises^[1]. For semax, the parts that shape what a covered spray looks like are:

• Route and form. Semax free base, intranasal use only. Appendix B lists its sequence as H-Met-Glu-His-Phe-Pro-Gly-Pro-OH with a molecular weight of 813.9 g/mol^[1]. Semax for injection is outside the policy.
• One active ingredient. Condition 7 allows a single active pharmaceutical ingredient from Appendix A. A spray that combines semax with selank, or with anything else active, does not qualify. Selank is not on Appendix A at all^[1].
• A patient-specific prescription filled by a State-licensed pharmacy, a Federal facility or a licensed physician^[1].
• A tested source. The bulk semax must come from a facility registered with FDA, with a certificate of analysis covering identity, purity, potency, endotoxin, heavy metals, microbial contamination and impurities, and the original manufacturer's location listed on it^[1].
• A label that says “This is a compounded drug product. Not for resale.”, and reporting of serious adverse events and product quality problems to FDA MedWatch and the states^[1].
• Device limits. Condition 9 says the only drug delivery device that may be co-packaged with or contain the compounded drug is an FDA 510(k)-cleared syringe^[1]. The policy does not discuss nasal spray pumps by name. How pharmacies dispense semax for nasal use under that condition is something to ask the pharmacy directly.

The policy also records the history. Semax was in FDA's Category 2 from September 29, 2023 until April 22, 2026; FDA's drug center (CDER) recommended against listing it, and the Pharmacy Compounding Advisory Committee voted in favor. HHS justified covering it with new certificates of analysis that supply the endotoxin result CDER had called the main gap for injectable use, documented use, and its reading that CDER's safety concerns were mechanistic rather than observed^[1]. The other five peptides on the list and their routes are in the policy explainer. Our news report on the announcement covers what changed.

Safety of semax nasal spray: known and unknown

HHS's justification says the intranasal human record CDER compiled “covers several hundred subjects with no reported adverse outcome,” and that the bleeding and abuse-potential signals CDER raised have no clinical counterpart in that record^[1]. The 2005 Russian study in 187 patients likewise described semax as well tolerated, including in older patients^[9]. That is consistent, but it has limits:

• The exposures were short courses, often two 10-day blocks^[6][7]. There is no published record of daily nasal use for months or years, which is how many US buyers use it.
• The subjects were mostly patients in Russian clinics. Side-effect reporting in small open-label studies tends to miss uncommon problems.
• Nasal-specific effects, such as irritation of the nasal lining with repeated use, are not described in the abstracts we reviewed. Absence from an abstract is not evidence of absence.
• A compounded spray also contains a vehicle and possibly a preservative chosen by the pharmacy. Those choices, not just the peptide, affect how a spray feels and how long it stays sterile once opened.

The larger, better-documented risk is product quality outside the pharmacy system. Belgian regulatory chemists analyzed two unknown preparations seized in 2017 and 2018 and found semax and selank; an online search showed these nootropic research peptides were freely sold as injectable powders and in nasal sprays^[10]. A “research use only” spray has no prescription, no required certificate of analysis and no adverse-event reporting. Our guide to whether peptides are legal covers why those products remain outside the law for human use.

Compounded spray vs research-chemical spray vs injectable vial

What to check before using a semax spray

1. It comes from a prescription written for you and is filled by a State-licensed pharmacy. Our pharmacy legitimacy lookup and the 503A pharmacy glossary entry explain what that means.
2. The label carries the statement “This is a compounded drug product. Not for resale.”
3. Semax is the only active ingredient. A “semax selank” spray is outside the policy.
4. The pharmacy can tell you who manufactured the semax and show that the lot was tested.
5. Ask how the spray is dispensed. Condition 9 names a 510(k)-cleared syringe as the only device that may come with the product and does not mention nasal pumps, so it is fair to ask the pharmacy how its spray bottle fits that condition.
6. The strength and schedule come from your prescriber. There is no US labeled dose; the regimens in the Russian studies were for stroke and neurological disease and do not translate into a dose for a healthy adult. Our semax dosage page explains why no chart exists.

Our semax provider page lists every seller we confirmed sells semax as a single-ingredient product, shows the form each one sells, and labels injectable semax as a form the policy does not cover; semax-selank blends are left off. A listing does not confirm that the pharmacy meets the policy's other conditions, including the device question above, so work through the checklist yourself: a certificate of analysis, a single active ingredient, the label line, the intranasal route, the device, and a State-licensed 503A pharmacy.

Bottom line

Semax has been studied mainly as a nasal drug, and the draft HHS policy follows that: compounded semax is covered only as an intranasal product, only as a single ingredient, and only under ten conditions, one of which names a syringe as the only allowed device and leaves nasal pumps unaddressed^[1]. The human evidence for nasal semax is a handful of small Russian studies in sick patients with mostly favorable reports and no serious problems recorded, plus one imaging study in healthy volunteers^[5][6][7][8]. That is not proof that it works as a nootropic, and it says little about long-term daily use. For other peptides whose allowed route shapes the product, see KPV capsules, cream or injection and TB-500 side effects and safety, or browse the full peptide guides.