Also called ACTH(4-7)-Pro-Gly-Pro, Met-Glu-His-Phe-Pro-Gly-Pro, ACTH(4-10) analog
Russian nasal drops built from part of a stress hormone, used there after strokes.
Semax is a lab-made peptide built from a small piece of ACTH, a stress hormone, plus a short tail that keeps it from breaking down so fast. In Russia, where it was made in the 1980s, it's a registered medicine sold as nasal drops: 0.1% for memory and focus problems tied to poor blood flow in the brain, and 1% for the early phase of a stroke. It isn't approved in the US, EU or UK.
Even though it comes from a stress hormone, it doesn't set off a stress response. In rats, it raises a natural growth signal (BDNF) that helps brain cells survive and connect, and it changes genes tied to swelling and blood vessels after a stroke. How much of this happens in people isn't well known.
Some human studies
Most human data come from Russian clinics. In one study of 110 people recovering from stroke, those who got Semax on top of rehab did better on a daily-living scale, but there was no dummy-drug group to compare with. There are no large, independent trials against a dummy drug, so claims that it sharpens focus or memory in healthy people are unproven.
Why: This follows the Russian (not FDA) package leaflet. Semax breaks down in the blood within minutes, so it's taken more than once a day, and the nose is a fairly direct route to the brain.
Why: This was used under medical care for Russian stroke patients (Gusev 2018). It's a hospital-style dose for brain injury, not a guide for healthy people.
Why: This range is widely shared online but untested in trials. Many skip evening doses because people often say it feels stimulating.
Start at the low end, and change one thing at a time. If you take medication or have a health condition, check with a doctor first.
Set up for a 5 mg vial. Change any number to match yours. New to this? Read how to mix a vial and mg vs mL vs units first.
Pick your dose and how long you'll run it. We'll count what you need.
Get help right away for swelling of the face or throat, trouble breathing, chest pain, or a spreading, hot, red injection site.
Powder: fridge or freezer. Once mixed, or once a nasal bottle is opened: fridge, use within about 2–4 weeks.
FDA: Not approved in the US. Semax was placed on FDA's compounding safety-concern list in 2023, then removed in April 2026 after the nomination was withdrawn. In July 2026 an FDA advisory committee voted 8–5 to recommend allowing it in compounding; FDA had not issued a final decision when last checked.
Sport (WADA): Not named on the WADA list. Because it is approved in Russia it may not count as a 'non-approved substance' (S0), but this is unclear. Athletes should ask their anti-doping agency before using it.
Not like caffeine or Adderall, but many users say it feels energizing, so most take it early in the day.
Studies say no. Semax is built from a part of ACTH that doesn't trigger the body's main stress hormone, cortisol.
A modified version sold online, with chemical caps on each end meant to make it last longer. It has far less published research than plain Semax.
Last checked 2026-10