Semax
A nasal spray or small shot that sharpens focus and drive within the hour, the stimulating half of the Russian Semax and Selank pair.
What it is
Semax is for the days your brain will not start: slow focus, low drive, the fog after a stretch of bad sleep or burnout. Taken in the morning it gives a clean lift in attention and motivation inside an hour, without the jitter of caffeine or the crash of stimulants.
It suits people doing demanding mental work who want sharper attention and more drive without a stimulant, and people climbing out of a stressful period who feel mentally flat. It is a prescription medicine in Russia, where it was developed, used for stroke recovery and attention problems, and it has been in use there for decades. Where Selank calms, Semax lifts; people with anxiety usually do better on Selank, and the two are often run together.
Most people feel it the first day: 15 to 30 minutes after a nasal dose, attention narrows, tasks feel easier to start, and the effect lasts three to five hours. Over two to three weeks there is a steadier baseline of mood and drive that outlasts any single dose. What good looks like is getting into work faster and staying in it, and recovering mentally after stress in days instead of weeks. It will not make you smarter, and if you are sleep-deprived it will cover the fog without fixing it.
Our doses are 300 mcg to start and up to 500 mcg a day, taken in the morning, as a subQ shot or, more commonly, as a nasal spray; a 10 mg vial mixed with 1 ml is 10 mg/ml, so 300 mcg is 3 units on an insulin syringe or the equivalent sprays once you know your bottle's output per spray. Runs are up to 8 weeks, then 2 to 4 weeks off: the lift tends to fade with daily use, and the break is what brings it back, so if it fades sooner, take the break then. The two mistakes are taking it after noon, which leaves people wired at bedtime, and chasing a bigger hit with a higher dose, which turns the lift into irritability. Mixed Semax does not keep long, a few weeks in the fridge, so a 10 mg vial at 300 mcg a day (about 33 doses) should be used, not stored.
The evidence is a mix of Russian clinical use and smaller studies, mostly on stroke, attention and stress, plus solid animal work on BDNF, the brain's main growth and repair signal. There is nothing from large Western trials and it is not approved in the US. For focus and drive the consistent human experience is the main evidence; take it as well supported for feel, thinly supported on paper.
If your problem is anxiety or stress reactivity rather than focus, Selank is the better first choice. If you want the stronger, longer version, N-acetyl Semax amidate is the one experienced users move to. Dihexa is not an alternative to Semax; it is an experimental compound with real cautions. Skip Semax if you have a history of psychosis or mania, or if you already take a stimulant for ADHD without telling your prescriber.
What people use it for
Focus and mental energy
Some evidenceSemax is approved in Russia for attention and cognitive deficits, with smaller clinical studies there showing better attention and learning, and consistent reports of same-day effects from users. Animal work shows it raises BDNF, which supports attention and learning circuits. No large Western trials.
Stroke and brain recovery
Some evidenceIts main approved use in Russia is for ischemic stroke, where higher-strength nasal doses given early improved recovery scores in Russian clinical studies. This is the strongest human data it has, and it is why people use it after concussion or burnout, though those uses are extrapolation.
Stress and burnout
Early daysAnimal studies show Semax blunts the stress response and protects brain cells under stress, and people use it to climb out of a flat, exhausted period. The human data for that specific use is thin; the experience is consistent.
How it works
Selank and Semax, the nootropic pair
- Used for focus, mental drive, and recovering from mental fatigue
- Usually taken as a nasal spray
- Linked to brain growth factors like BDNF
- Mostly Russian research; limited Western trials
How people use it
Safety, in brief
Things people sometimes notice
- Mild nose irritation or a runny nose after a spray
- Feeling wired or restless if you take it after midday or go too high
- A mild headache in the first days
The full picture — stop signs and who should talk to a doctor first — is on the dosing guide.
Sources
The labels and studies behind this page. Each link opens the original on PubMed, DailyMed or ClinicalTrials.gov.
- The efficacy of Semax in the treatment of patients at different stages of ischemic stroke
- Semax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampus
- Antidepressant-like and antistress effects of the ACTH(4-10) synthetic analogs Semax and Melanotan II on male rats in a model of chronic unpredictable stress