Overview

Semax is a lab-made peptide built from a small piece of the stress hormone ACTH, with three amino acids added so it lasts longer. In Russia it is used as a prescription nasal drug for stroke and memory problems. It is not approved in the US, but an FDA advisory panel voted in July 2026 to recommend allowing pharmacies to compound it.

How it works

Proposed. Semax does not have ACTH's hormone (cortisol-raising) activity. Animal studies report that it raises BDNF and its receptor trkB in the rat hippocampus, and activates dopamine and serotonin systems in rodents. It also inhibits enkephalin-degrading enzymes in human serum in lab tests. These are mainly rodent and cell findings. ⁶¹¹

What research shows

Russian clinical and electrophysiological study of Semax in the acute period of hemispheric ischemic stroke (2001) — small, published in Russian; full design details not verified here ⁷.
Rat study: Semax regulated BDNF and trkB expression in the hippocampus (Dolotov et al., 2006) ⁶.
Rodent study: Semax activated dopamine and serotonin brain systems (Eremin et al., 2005) ¹¹.
Review (2006) proposed Semax as a candidate for ADHD and Rett syndrome based on preclinical data ⁸.
FDA staff reviews in June 2026 recommended against adding Semax (and the other six peptides reviewed) to the 503A bulks list; FDA's briefing material was cited for possible risks such as cancer or bleeding. The advisory committee still voted in favor ³⁴¹³.

Doses studied in people

No verified dose from a published trial was confirmed in this review; Russian product labeling exists but was not available from a primary source.

Read this first: these are the amounts given to participants in published studies or written on official prescribing labels, reported for reference. They are not recommendations. Trial doses were chosen for specific patients under medical supervision, and a dose that is safe in one person can be harmful in another.

Weekly protocol

How the schedule looks week by week. Each chart says where it comes from: a prescribing label, a clinical trial, or a protocol commonly reported online.

Ischemic stroke study (Gusev 2018)

Clinical trial

One week

D1D2D3D4D5D6D7

Three times daily · Nasal drops (1% solution)

Dose by week

6,000 mcg/dayCourse 1 · wk 1–2

NoneOff · wk 3–4

6,000 mcg/dayCourse 2 · wk 5–6

Course: Two 10-day courses with a 20-day break between them
Note: Hospital stroke patients in Russia. Each course lasts 10 days, so week boundaries are approximate.
Source: Gusev EI et al. The efficacy of Semax in the treatment of patients at different stages of ischemic stroke. Zh Nevrol Psikhiatr Im S S Korsakova 2018;118(3-2):61-68

Commonly reported nootropic course

Commonly reported, not studied

One week

D1D2D3D4D5D6D7

Two to three times daily · Nasal spray or drops (0.1% solution)

Dose by week

200–600 mcg per dosewk 1–2

Course: 10–14 days, repeated after a 2–4 week break (2–4 courses a year)
Note: Mirrors Russian 0.1% drop use. PeptideDosages.com lists 200–300 mcg per dose, 2–3 times in the first half of the day, for 5 days.
Source: Peptide Protocol Wiki: Semax dosing protocols
Also: PeptideDosages.com: Semax (5 mg) dosage protocol

Reference only, not a recommendation. Charts marked "commonly reported" describe what public sources say people use. They have not been tested in trials, and their safety and effect are unknown. Label and trial schedules were set for specific patients under medical supervision. Use the calculator only to understand the arithmetic.

Vial math

Many research vials hold 5 or 10 mg of powder. This table shows how much ends up in each mark on a U-100 insulin syringe for common amounts of added liquid. It is arithmetic only, not a dose.

Vial	Liquid added	Concentration	Per unit (0.01 mL)
5 mg	1 mL	5 mg/mL	50 mcg	Open in calculator
5 mg	2 mL	2.5 mg/mL	25 mcg	Open in calculator
5 mg	3 mL	1.67 mg/mL	16.7 mcg	Open in calculator
10 mg	1 mL	10 mg/mL	100 mcg	Open in calculator
10 mg	2 mL	5 mg/mL	50 mcg	Open in calculator
10 mg	3 mL	3.33 mg/mL	33.3 mcg	Open in calculator

More sizes: all vial sizes · How this works: Syringes and units · Reconstitution guide.

Safety

FDA's 2026 briefing material for Semax was cited for possible risks such as cancer or bleeding; the specific risk was not detailed in the sources reviewed ⁴.
Large, independent long-term safety data are lacking; long-term safety is unknown.
Unregulated 'research' products may vary in purity and content.

Report side effects of any drug or product to the FDA through MedWatch. For a possible poisoning in the US, call Poison Control at 1-800-222-1222.

Legal status

FDA: Not FDA-approved.
Compounding: Removed from 503A Category 2 in April 2026 after the nomination was withdrawn; PCAC voted 8–5 on July 24, 2026 to recommend adding it to the 503A bulks list. The vote is non-binding — FDA must still do notice-and-comment rulemaking, and as of the latest reports reviewed (Aug–Sept 2026) FDA had not placed it in Category 1 or announced enforcement discretion ¹²³⁵. Update: on October 28, 2026 HHS issued an interim enforcement discretion policy covering Semax: HHS does not intend to take action against 503A pharmacies, federal facilities or physicians that compound it under set conditions (patient-specific prescription, FDA-registered ingredient source with a certificate of analysis, single ingredient, adverse-event reporting), limited to nasal use. This is not FDA approval, is non-binding, and applies only until a final rule on the 503A bulks list ¹⁴¹⁵.
Sports (WADA): Not named on the 2026 List. Because it is approved in Russia, whether S0 (non-approved substances) applies is unclear — confirm with your anti-doping organization ⁹.
Other: Prescription drug in Russia (nasal drops/spray).

Rules change often. See Legal status of peptides for how these categories work.

History

First described in the scientific literature around 1991 by Russian researchers ¹⁰. It is used in Russia as a prescription drug and appears on the Russian List of Vital & Essential Drugs (approved December 2011, per a secondary source ¹²). In the US, FDA listed Semax in its 503A Category 2 safety list until the nomination was withdrawn and it was removed in April 2026; the Pharmacy Compounding Advisory Committee then voted 8–5 (1 abstention) on July 24, 2026 to recommend adding it to the 503A bulks list ¹².

Common questions

Is Semax FDA-approved or legal to compound?

It is not FDA-approved. In July 2026 an FDA advisory committee voted 8 to 5 to recommend allowing pharmacies to compound it, but the vote is non-binding and FDA must still go through rulemaking ²⁵. Update: on October 28, 2026 HHS issued an interim, non-binding policy saying it does not intend to take action against licensed pharmacies, federal facilities or physicians that compound Semax under set conditions, including a patient-specific prescription. This is not FDA approval, and it applies only until a final rule on the 503A bulks list ¹⁴¹⁵.

Is Semax a hormone?

It is built from a small piece of the stress hormone ACTH, but it does not have ACTH's cortisol-raising hormone activity ⁶¹¹.

What does the research show?

Most evidence is from rodents, such as higher BDNF (a brain growth factor) in the rat hippocampus and activation of dopamine and serotonin systems ⁶¹¹. A small Russian study in acute stroke was published in Russian, and its full design was not verified ⁷.

What doses were studied in people?

No dose from a published trial was confirmed. Russian product labeling exists but was not available from a primary source.

Is Semax safe?

FDA's 2026 briefing material was cited for possible risks such as cancer or bleeding, though details were not given in the sources reviewed ⁴. Large, independent long-term safety data are lacking.

Is Semax banned in sport?

It is not named on WADA's 2026 list ⁹. Because it is approved in Russia, it is unclear whether the S0 rule for non-approved substances applies, so athletes should check with their anti-doping organization ⁹.

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