Semax / Selank dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
Semax / Selank is two Russian peptides sold as a pair, either as two nose sprays or one combined bottle.
Evidence grade for Semax / Selank: Moderate. The rule: at least one finished study in people, and at least 100 people who took it. The sum on this page: 2 completed trials, 172 people given it. A grade counts how much has been done to people, not whether it works.
- People given it
- 172
- Human studies
- 2
- Found nothing
- 0
Dose
No human dose established
Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose.
2 completed trials, 172 people given it
9 effects reported, 6 unwanted, 3 wanted, by people using it, not a trial
Goal pages: Brain, memory and mood, Heart and circulation, Sleep
In plain English
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
These are two Russian brain peptides sold as a pair. You spray them up your nose. One is meant to sharpen you up. The other is meant to calm you down. You can buy them as two bottles or as one mixed bottle. Both are approved medicines in Russia. Neither is approved here. Nobody has ever tested them together.
What people take it for
- Focus and clearer thinking at work.
- Taking the edge off anxiety without feeling drugged.
- Handling stress better over a few weeks.
- Some people believe one balances out the other. Nobody has tested that.
What studies in people showed
There is no study of the two together. Each one on its own has Russian studies, and they are not the kind of study this site calls strong. The sharp one was given to 110 people after a stroke. They got better faster. But everyone knew who got what, and there was no dummy group. The calm one went to 62 people with anxiety. It worked about as well as a benzo it was compared against. There was no dummy group there either. The rest is rats. Now the mix. In Russia the two are sold at different strengths. The sharp one is 1 mg per mL, so a spray gives about 100 micrograms. The calm one is 1.5 mg per mL, so a spray gives about 150. Mixed bottles sold here usually put 2.5 mg per mL of each in. That is a spray of about 250 micrograms of each, which is more of both and a ratio that matches neither Russian product. Here is the real problem. The whole point of this pair is balance. Balance means moving one and not the other. One bottle takes that away. If the sharp one has you wired, cutting back also cuts the calm one, which was the reason you bought the pair. One more thing worth knowing. A Belgian lab tested two mystery products seized in 2017 and 2018. They turned out to be these two peptides. The lab wrote a detection method because this stuff circulates with no label on it.
What people report
Reports, not study results
The good
- Sharper focus and words coming easier, 20 to 40 minutes after a spray.
- A flatter, calmer mood people credit to the second peptide. Not sleepy, just less edgy.
- Handling a stressful stretch better after a few weeks of use.
The bad
- Wired, irritable and unable to sleep if the sharp one goes in too late in the day. This is the most common complaint, and it is the reason people add the second one.
- Headache.
- A stinging, runny nose. People blame the volume and the preservative more than the peptides.
- A bitter metal taste at the back of the throat.
- Nothing at all, which people blame on the seller. Given that unlabelled samples have been seized in Europe, that is a fair worry.
- Losing track of which one is doing what. That only happens with the mixed bottle.
Where these come from: None of this is from a trial, because there is no trial of the pair. It comes from nootropic and peptide forums such as r/Nootropics and r/Peptides, and from seller and clinic write ups. The Russian studies on this page did not collect side effects the way a Western trial does.
My bottom line
If you are going to run this pair, buy two bottles, never one. The whole idea is dialling one up and the other down, and a mixed bottle is the one format that will not let you do it.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Measured in people
Goals Semax / Selank has been tested for in people, biggest studies first. We count only what the studies on this page say, so the real numbers may be higher.
- Heart attacks and strokes110 people · 1 study
- Mood and anxiety62 people · 1 study
What people using it report
Real people telling you what happened to them. Nobody checked it, and the people who post are not a fair sample, so it cannot prove anything works. It is still the best guide on this page to what people actually do with Semax / Selank, what they expect, and what goes wrong. The full account, including the negative reports, is below.
Animal and lab work, not yet tested in people
Real results, but from animals or cells, not people. What works in a mouse often does not work the same way in a person. Nobody can patent this, so nobody would ever earn back the cost of a study in people. That is usually why there is none. The record on this one is set out below.
- Memory and thinking1 animal or lab study · users report on this
32 of the 36 indexed goals have no study of any kind behind Semax / Selank
No study in people, animals or cells on this page reports a result for these. That does not prove Semax / Selank does nothing for them. It does mean anything you have heard about Semax / Selank and one of these did not come from a study cited here.
Show full evidence
What is Semax / Selank?
Semax / Selank is two Russian peptides sold as a pair, either as two nose sprays or one combined bottle. The pitch is that one sharpens and the other calms. No study has tested them together. Each has Russian data in people: 110 stroke patients for Semax, and 62 anxiety patients for Selank. Neither study compared the drug against a dummy. A combined spray at 2.5 mg per mL of each flips the split the two are registered at in Russia.
Semax and Selank came out of the same Russian research program and ended up in the same medicine cabinet. Semax is a lab-made copy of a piece of ACTH, a stress hormone. The piece is called ACTH 4-10. Semax is registered in Russia and Ukraine for stroke recovery and thinking problems. Selank is a lab-made copy of tuftsin, a small natural peptide, and is registered in Russia for anxiety. The pitch for the pair is simple. Semax is the one that wakes you up, Selank is the one that calms you down, and together you get focus without the edge. That is a believable story. Nobody has tested it.
What has been tested is each peptide alone, in Russia, mostly without a dummy group and without hiding who got what. On the rest of this site, those are what a Strong rating rests on. The main Semax study followed 110 people after a stroke. BDNF, a brain growth factor, rose in their blood. They also regained everyday abilities faster, on a score called the Barthel index. There was no dummy group, and nobody was kept in the dark. The main Selank study split 62 people with long-running anxiety or nervous exhaustion (neurasthenia) between Selank and medazepam, a Valium-type drug. Both calmed anxiety about equally. There was no dummy group, only the other drug.
In rats, Semax raised BDNF and its receptor in the memory center of the brain. In rats and mice, Selank and its tuftsin relatives eased stress behavior. None of that animal work used the other peptide.
The split on this blend is the one case in this group where the math comes out almost even. Semax weighs 813.9 Da and Selank weighs 751.9 Da. So an equal-weight mix is also close to an equal-molecule mix, with about 8 percent more Selank molecules per milligram. That sounds tidy until you compare it with how the two are registered. In Russia, Semax is a 0.1 percent nose solution, 1 mg per mL, giving about 100 micrograms in a 0.1 mL spray. Selank is a 0.15 percent solution, 1.5 mg per mL, giving about 150 micrograms per spray. So the registered products run at 1 to 1.5, with more Selank. Combined sprays sold to consumers are often mixed at 2.5 mg per mL of each. That is 50:50, and gives about 250 micrograms of each per spray. It is a different split from either registered product, and a higher dose of both per spray.
The specific problem with a combined spray is that it removes the one adjustment that matters for this pair. The whole reason to take Semax with Selank is to balance wake-up against anxiety, and balancing means moving one without the other. In one bottle, every dose of the wake-up peptide is also a dose of the calming one, at a split someone else picked. If the Semax is too much, the only fix also lowers the Selank that was meant to take the edge off. Two bottles cost more and take two sprays. They are the only version of this stack you can actually tune.
There is a supply problem worth stating plainly too. In 2020, a Belgian lab looked at two suspicious products seized in 2017 and 2018. They held Selank and Semax. The authors said that, as far as they knew, neither peptide had finished any clinical trial. The pair turns up as unlabeled powder and spray often enough that a national testing lab built a method just to detect it.
How does Semax / Selank work?
Semax is a copy of ACTH 4-10 with extra pieces added to make it last. It raises BDNF and NGF, two growth factors for brain cells, and shifts dopamine and related brain signals. In rats, a single dose raised BDNF protein in the memory center of the brain and switched on its receptor, trkB. Selank, a tuftsin copy, shifts GABA, the brain's main calming signal, and mood chemicals like serotonin and dopamine. It also affects the breakdown of enkephalins, the body's own calming peptides, and the making of BDNF. It eases anxiety without the drowsiness of Valium-type drugs. The idea behind the pair is that both touch brain growth pathways, while pushing alertness in opposite directions. No study has measured what either does to the other.
What have studies in people found about Semax / Selank?
Each peptide has Russian data in people, at a level this site rates Moderate at best. Neither study compared the drug against a dummy. There is no human data on the two taken together.
- Semax, 110 people after a stroke: BDNF in the blood went up, and everyday abilities came back faster on the Barthel index. No dummy group, and nobody was kept in the dark.
- Selank, 62 people with long-running anxiety or nervous exhaustion: it calmed anxiety about as well as medazepam, a Valium-type drug, and was also reported to ease tiredness and boost alertness. Compared against another drug, with no dummy group.
- Both are registered medicines in Russia, Semax for stroke and thinking problems and Selank for anxiety. That is a legal fact, not a trial result.
- A Belgian testing lab looking at seized products in 2020 noted that, as far as it knew, neither peptide had finished any clinical trial.
What this does not tell you: No published study has given Semax and Selank to the same person. Nobody has measured whether Selank dulls the lift people take Semax for, or whether Semax undoes the calm people take Selank for. Nobody has checked whether the pair does anything neither does alone. How well either peptide gets in through the nose has not been measured outside Russia. So the dose per spray is what goes into the bottle, not what reaches the brain. Nothing has been published on whether the two stay stable together in one liquid.
What do people who took Semax / Selank report?
This is what real people say happened to them, good and bad. Nobody measured it. A report cannot tell a real effect from the lift people get just from expecting it to work, from a diet or training change made at the same time, or from what was really in the vial. We still put it near the top. It is the next best thing to a study in people: what happens when real people use it, including what goes wrong.
- Sharper focus and easier word recall within 20 to 40 minutes of a Semax spray. This is the most common report on the pair.
- A flatter, calmer mood, credited to the Selank and described as taking the edge off without making people drowsy.
- Handling stress better over several weeks, rather than right away.
- Feeling overstimulated, irritable or unable to sleep when Semax is taken late in the day. This is the most common complaint, and the reason people add Selank in the first place.
- Headache and a stinging or runny nose, which users blame on the spray volume and the preservative rather than the peptides.
- A metallic or bitter taste at the back of the throat after a spray.
- No effect at all. This is common, and usually blamed on seller quality, given that seized samples have turned up unlabeled.
- Losing track of which peptide is doing what. That happens with the combined bottle, not with two separate sprays.
Sources: None of this is from a trial. There are no exit interviews for the combination because there is no trial of the combination. These reports come from nootropic and peptide user forums including r/Nootropics and r/Peptides, and from vendor and clinic write-ups. The Russian studies cited on this page did not collect side effect data in a form comparable to a Western side-effect table.
The state of the research
The evidence gap here is partly about geography, not only money. Both peptides went through a Soviet and then Russian approval path, with study standards Western regulators do not accept. The research that came out of it is real. But it sits a level below a trial with a dummy group where nobody knows who got what. That does not mean nothing happened in those studies. It means a Russian registration and a 110-patient study with no dummy group are not what 'approved' means on the rest of this site. A combined product built on two records like that inherits both weaknesses, and adds a third.
The practical problem with this blend is unusually clear, because the two parts are meant to pull in opposite directions on the same dial. Wake-up versus calm is the one pairing where the split is the whole product. Fixing it in one bottle, at a split that matches neither Russian product, leaves the user no way to find their own balance. It also leaves no way to tell which peptide did what. If a combined spray makes someone anxious and wired, they cannot tell if the Semax is too high or the Selank is not working. The only lever they have moves both.
The supply side deserves its own sentence. The Belgian lab work exists because these peptides show up as unlabeled material, and the same paper notes they are sold openly online as powder and sprays. Someone buying a combined spray is trusting a compounder's split and a compounder's word on what is inside, with no registration behind either.
The evidence, in charts
Fig. 1a · how many people
172people, across 2 studies in people cited here
| Study | People | Share |
|---|---|---|
| Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova 2018 | 110 | 64% |
| Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova 2008 | 62 | 36% |
One study holds 64% of these people, so the total rests more on one study than its size suggests. Counts are the number of people each study on this page says it signed up. That includes studies that only watched people and gave nobody the compound. Studies still signing people up are left out, and only studies cited on this page are counted.
Fig. 1b · evidence mix
2 of 5 sources here are studies in people. The rest are not.
- Study in people · done in people240%
- Animal study · done in animals240%
- Review of studies · sums up other studies120%
Counted from the list of sources on this page. It counts only what we cite, so there may be more studies out there. A review counts once, however many studies it sums up.
Fig. 2 · evidence over time
The studies cover 5 different years, 2003 to 2020, counted from the list of sources on this page. The newest source on file is from 2020, more than five years ago. Research on it may have gone quiet.
Fig. 3 · legal status at a glance
US
Not approved
UK
Not approved
AU
Not approved
CA
Not approved
Not approved in any of the four countries shown. This is what the law says, not a verdict on the science. See Legal status below for the full text and any notes.
Fig. 4 · how much does what
Nobody has tested different amounts in people
This chart would show how the effect changes as the amount goes up. For this compound, nobody has measured that in people. So we leave it empty. We will not borrow an animal chart and pretend it works the same in people.
Fig. 5 · what the molecule is
- Kind of compound
- Blend
- Molecule weight
- Mixture; Semax 813.9 Da, Selank 751.9 Da
- Half-life
- Stated in words, not a numbersee the exact wording below
- Chain length
- None on file
Half-life as stated on file: Not one number, and neither component has published nasal pharmacokinetics in the West. Both are described as clearing within minutes.
No amino acid sequence is on file for Semax / Selank, which is expected: a blend is not built from amino acids.
Fig. 6 · what is in the vial
We cannot show how much of each is in this blend
Sellers do not agree on a vial size for Semax with selank, so nobody outside can know how much of each ingredient is in it. Splitting the bar evenly would make up the very number this page is here to question.
- SemaxModerate. At least one finished study in people, and at least 100 people who took it. 4 completed trials, 354 people given it.amount not stated
- SelankModerate. At least one finished study in people, and at least 100 people who took it. 3 completed trials, 192 people given it.amount not stated
Ingredient list from the product labels we have. Amounts are what the label says is in the vial, never a dose.
The studies we cite
- Study in people2018The efficacy of semax in the treatment of patients at different stages of ischemic stroke
A Russian study of Semax after stroke, with a design too loose to trust. A hundred and ten people recovering from a stroke were given courses of the drug. A growth factor in their blood rose, and they regained everyday abilities faster, things like washing, dressing and moving about. Nobody was kept in the dark about what they were getting and there was no dummy group. That matters most for a recovery score, which improves on its own anyway. No Selank was given.
Russian clinical study of 110 post-stroke patients. Semax courses raised plasma BDNF and were associated with faster Barthel index improvement. This was not a blinded placebo-controlled trial, and no Selank was given.
- Study in people2008Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the therapy of generalized anxiety disorders and neurasthenia
Selank calmed anxiety about as well as a standard sedative did. Sixty two people with long running anxiety or exhaustion were split by chance between Selank and medazepam, a drug in the same family as valium. Both groups improved by a similar amount, and the Selank group was also described as less tired and more alert. Nobody got a dummy, so there is no way to know how much of either result was the drug and how much was time and attention. No Semax was given.
62 patients with generalised anxiety disorder or neurasthenia randomised to Selank, 30 patients, or the benzodiazepine medazepam, 32 patients. Anxiolytic effects were similar between the two, and Selank additionally showed anti-asthenic and psychostimulant effects. An active comparator design with no placebo arm, and no Semax given.
- Review of studies2020The occurrence of putative cognitive enhancing research peptides in seized pharmaceutical preparations: An incentive for controlling agencies to prepare for future encounters of the kind
In a lab, on seized products. Belgian authorities seized two mystery products in 2017 and 2018. Lab tests found Selank and Semax inside. The authors say that, as far as they know, neither peptide has finished a clinical trial, and both are sold freely online as powder and nose sprays.
Two unknown suspicious preparations seized in Belgium in 2017 and 2018 were analysed and found to contain Selank and Semax. The authors state that to their knowledge neither peptide has completed any clinical trials, and note the pair is freely sold online as lyophilised powder and as nasal sprays. A national control laboratory built an LC-MS/MS method specifically because these were circulating unidentified.
- Animal study2006Semax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampus
In rats. One dose of Semax raised BDNF, a brain growth factor, and switched on its receptor in the memory center of the brain. The rats also got better at a learning task. This is the basis for how the Semax half is meant to work, not evidence about the pair.
A single dose of 50 micrograms per kilogram raised hippocampal BDNF protein 1.4-fold, trkB phosphorylation 1.6-fold and BDNF mRNA 3-fold in rats, alongside improved conditioned avoidance learning. Rats, Semax alone, one dose. The mechanistic basis of the Semax half, not evidence about the pair.
- Animal study2003Selank and short peptides of the tuftsin family in the regulation of adaptive behavior in stress
In rats and mice. Under stress, Selank and related peptides improved mood-like behavior and eased stress. Selank alone.
In rats and mice under conflict-induced emotional stress, Selank and related tuftsin-family peptides produced positive emotional and anti-stress effects. Rodents, Selank alone.
Where to buy Semax / Selank
19 sellers list Semax / Selank in our latest read. They are ranked by trust score, then by archive rating, then by certificate tier, then by the lowest price per milligram. Archive evidence is counted before source-backed. Each path is out of 4, and the two are not added. A higher price does not raise the score. The letter is the certificate chip. 2 of them have a published certificate that names Semax / Selank.
Some seller links may pay this site when you buy through them. A payment never changes a seller's tier or rank, and no seller has a say in any page.
| Seller | Trust score | Vial sizes | From, per mg | Certificate for Semax / Selank | Seller link |
|---|---|---|---|---|---|
| EZ Peptides | 75 StrongSource-backed 4 of 4. Archive evidence 3 of 4.A | 10 mg | $8.80 | None found for Semax / Selank | View |
| Area 15 Labs | 73 StrongSource-backed 4 of 4. Archive evidence 2 of 4.A | 20 mg | $4.00 | None found for Semax / Selank | View |
| ezPeps | 73 StrongSource-backed 4 of 4. Archive evidence 2 of 4.A | 10 mg | $6.30 | None found for Semax / Selank | View |
| HYTE Research Division | 72 StrongSource-backed 4 of 4. Archive evidence 2 of 4.A | 20 mg | $4.50 | None found for Semax / Selank | View |
| NuLife Peptides | 67 FairSource-backed 3 of 4. Archive evidence 2 of 4.B | 5 mg, 10 mg | $8.00 | None found for Semax / Selank | View |
| Zenergy USA | 49 WeakSource-backed 3 of 4. Archive evidence 2 of 4.A | 10 mg | $3.30 | None found for Semax / Selank | View |
| Silverstone Labs Co | 49 WeakSource-backed 3 of 4. Archive evidence 2 of 4.A | 20 mg | $3.50 | None found for Semax / Selank | View |
| Peptify Labs | 49 WeakSource-backed 3 of 4. Archive evidence 2 of 4.A | 20 mg | $3.75 | Certificate, Freedom Diagnostics | View |
| Peptide Labs | 49 WeakSource-backed 3 of 4. Archive evidence 2 of 4.A | 10 mg, 20 mg | $6.40 | None found for Semax / Selank | View |
| Apex Amino | 49 WeakSource-backed 3 of 4. Archive evidence 2 of 4.A | 10 mg | $8.00 | None found for Semax / Selank | View |
| Molecular Edge Peptides | 49 WeakSource-backed 3 of 4. Archive evidence 2 of 4.A | 10 mg | $15.0 | None found for Semax / Selank | View |
| Sigma Compounds | 49 WeakSource-backed 3 of 4. Archive evidence 1 of 4.B | 5 mg, 10 mg | $9.70 | None found for Semax / Selank | View |
| Peplogix | 49 WeakSource-backed 3 of 4. Archive evidence 1 of 4.B | 10 mg | $17.5 | None found for Semax / Selank | View |
| Soma Peptides | 29 InsufficientSource-backed 4 of 4. Archive evidence 1 of 4.Letter withheld | 5 mg | $16.6 | None found for Semax / Selank | View |
| LabRat Peptides | 28 InsufficientSource-backed 1 of 4. Archive evidence 1 of 4.C | 50 mg | $1.20 | None found for Semax / Selank | View |
| Welli Labs | 27 InsufficientSource-backed 1 of 4. Archive evidence 0 of 4.Letter withheld | 10 mg | $4.00 | None found for Semax / Selank | View |
| True Research Labs | 25 InsufficientSource-backed 1 of 4. Archive evidence 1 of 4.C | 20 mg | $2.95 | None found for Semax / Selank | View |
| Neuro Labs | 25 InsufficientSource-backed 1 of 4. Archive evidence 1 of 4.C | 10 mg | $8.58 | None found for Semax / Selank | View |
| Glacier Aminos | 12 InsufficientSource-backed 4 of 4. Archive evidence 2 of 4.Letter withheld | 20 mg | $4.10 | Certificate, Kovera Labs, Freedom Diagnostics | View |
- LC Lab-confirmed: the issuing laboratory echoed this certificate back
- A Current certificate, independent laboratory named, laboratory not yet checked
- B Certificate published, but no laboratory link, older than a year, or the laboratory did not recognise the published lookup
- C No certificate could be read
Every listing and vial size for Semax / Selank · How the trust score is counted
Sellers named on the price pages are ranked by certificate tier, then price, and any affiliate income is disclosed there. Naming a seller is not a recommendation to buy or use anything.
Common questions
Has Semax / Selank been tested in people?
Yes. 172 people given it across 2 completed trials cited here, 0 of which found nothing. Semax / Selank is two Russian peptides sold as a pair, either as two nose sprays or one combined bottle.
What is the Semax / Selank dosage?
No human dose established. Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose. 2 completed trials, 172 people given it
Is Semax / Selank FDA-approved?
Not approved as a blend or on their own. Both are registered medicines in Russia. Neither has FDA or European Medicines Agency approval, and no combination product is registered anywhere.
Has Semax with Selank ever been studied?
No. Not together, in anyone, anywhere. The Russian studies used one peptide at a time. The idea that one balances the other is a fair guess that nobody has tested.
How much of each is in a combined spray?
Combined bottles are often mixed at 2.5 mg per mL of each, so a 0.1 mL spray gives about 250 micrograms of each. That is 50:50 by weight. Because the two molecules weigh almost the same, it is close to 50:50 by molecule count too. But it is not the split either drug is registered at in Russia, where Semax runs at 1 mg per mL and Selank at 1.5 mg per mL.
Should I buy the combined spray or two separate ones?
Two separate sprays, if you are going to do this at all. The whole point of the pair is balancing wake-up against calm. A fixed split in one bottle is the one thing that makes balancing impossible. It also means you can never tell which peptide caused an effect.
Is either of these approved anywhere?
Both are registered medicines in Russia, Semax for stroke recovery and thinking problems and Selank for anxiety. Neither is approved by the FDA in the US or the EMA in Europe. In the US, Semax was taken off the FDA's Category 2 list in April 2026. In July 2026, an advisory committee voted to recommend it for compounding. That vote changes nothing until the FDA finishes writing the rules.
Is Selank addictive like a benzodiazepine?
The published research does not describe the tolerance and dependence seen with Valium-type drugs. But the one study with a comparison group put it head to head with medazepam, not a dummy. That is a thin basis for a safety claim. Human evidence outside Russia is close to nonexistent.
How do I know what is actually in the bottle?
Mostly, you don't. A Belgian national testing lab analyzed two seized products and found Semax and Selank in them. It built a detection method because these circulate unlabeled. A combined spray bought online has no registration, no required batch testing and no independent lab check behind it.