Selank vs Semax

The Dose Guy’s verdict

Oct 27, 2026
6 sources

Pick by the job. Semax is for focus and drive, selank is for taking the edge off. If you only try one, I’d start with semax: it has the longer clinical track record and an effect you are more likely to notice. Selank is the pick when anxiety is the problem, and it is gentle enough that the most common outcome is a shrug. Both stand on small Russian studies, so set your expectations low on either. Plenty of people end up running the pair, semax in the morning and selank when the day gets loud.

Which would I take?Semax, unless calm is the goal.

How they differ

They push in opposite directions. Semax is built from a fragment of ACTH, the pituitary hormone behind your cortisol response, and it pushes: a clearer head, an easier start on hard work, sometimes a slightly wired or emotional edge in the first week. Selank is built on tuftsin, an immune fragment, and it pulls the other way: a lower baseline hum of worry with no sedation and no fog. Same Russian lab tradition, same short peptide design, opposite ends of the dial.

That makes them less rivals than tools for different days. If your problem is getting going, focusing, or recovering from a rough patch of brain fog, semax. If your problem is a nervous system that runs hot, selank, though be honest with yourself: selank is subtle, and if you need to feel a difference on a hard day, pregabalin gets there and selank probably won’t. If ADHD is why you searched, semax is the one the focus crowd reaches for, and nothing in either evidence base tests it in ADHD. Neither replaces a stimulant that is already working for you.

Whichever you pick, a bad fit costs you a day, not a week. Both are short nasal sprays that wear off within hours, so trying one is cheap and stopping it is instant.

What the research shows

Thin on both sides, and the only study that dosed both measured brain wiring, not anxiety or focus:

No trial has compared selank and semax for anxiety, focus, or anything a user would feel, and no randomized trial has tested semax for cognition in healthy people.as of Aug 2026

The one study that gave healthy people selank, semax, or placebo. The published finding is selank’s: it altered resting-state connectivity between the right amygdala and the right temporal cortex.Doklady 2020 · fMRI · n=52

In 62 patients with generalized anxiety or neurasthenia, selank in 30 and medazepam, a mild benzodiazepine, in 32 produced similar anxiolytic effects.Korsakov J 2008 · comparison · n=62

In 110 patients after ischemic stroke, two 10-day semax courses at 6000 mcg/day, 20 days apart, raised plasma BDNF and improved the speed and final outcome of Barthel index recovery.Zh Nevrol Psikhiatr 2018 · clinical · n=110

In healthy volunteers, intranasal 1% semax in 14 people produced a greater medial frontal default-mode-network subcomponent than placebo in 10.Bull Exp Biol Med 2018 · fMRI · n=24

Different studies in different people: selank’s best data is anxiety patients, semax’s is stroke patients. Neither has shown it sharpens or calms a healthy person in a trial.

How people run them

The dosing looks almost identical on paper, a few hundred mcg a day split into two or three sprays, so the rhythm is not what separates them. Timing is. Semax goes in the morning and early afternoon, because some people report a late dose sits between them and sleep. Selank goes in whenever you want the edge gone, ideally before evening too, and some people keep it as an as-needed spray for rough days rather than a daily habit. On both, a low dose you notice is the win; chasing a higher one rarely changes the experience.

Switching is just stopping one and starting the other the next morning. No washout, no taper, nothing builds up. Run semax in courses of two to four weeks with an equal break, because the lift plateaus; selank has no hard cycle, but if you stop noticing it after a few weeks, take a week off and ask whether it was doing anything.

Stacking is the common move, and it makes sense: selank smooths the wired, emotional edge some people get from semax. Start each one alone for a week first so you know which one is doing what. Neither is approved outside Russia, so whatever you buy is grey-market. Insist on a third-party COA for both, and keep the semax bottle in the fridge.

Semax200–600 mcg/day0.1% spray, two or three doses, morning and early afternoon.

Selank200–600 mcg/dayTwo or three sprays; most people stay at the low end.

Switchingnext morningBoth clear within hours, so there is nothing to wash out.

The stacksemax AM + selankSelank takes the wired edge off semax; learn each alone first.

Cycle2–4 weeks onThen a break, mainly for semax, whose lift plateaus.

Side effects, side by side

Both are about as gentle as this shelf gets; the difference is that semax can push a little and selank can settle a little:

commonNasal irritation or dryness from daily spraying, on both. Rotate nostrils.

anecdotalSemax: heightened emotionality, restlessness, or vivid dreams in the first week, usually fading. Some report poor sleep after a late dose.

anecdotalSelank: a mild calm heaviness at higher doses, not true sedation. The occasional short headache.

anecdotalSemax: hair shedding with prolonged use turns up in forums, unconfirmed by any study.

unknownNo human trial has measured adverse event rates or long-term safety for either one. Decades of Russian use is reassuring; it is not a safety study.