Pinc PeptideThe girly peptide research blog

Compare · updated 8 October 2026

Selank vs Semax

The short answer

Selank and semax come from the same Russian research team and are sold in Russia as nose drops: selank without a prescription for anxiety, semax on prescription for stroke and memory problems3456. We found no placebo-controlled trial showing that either works: selank’s anxiety studies compared it with benzodiazepines (Valium-type drugs) or added it to one, semax’s stroke studies had no placebo group, and FDA found ‘insufficient evidence’ for the semax uses it reviewed789101112. We found no study in people that compared the two on anxiety, focus or memory, so neither can be called better113.

At a glance

ComparedSelankSemax
Evidence tierB At least one controlled human trialB At least one controlled human trial
Does it work?For anxiety relief: Mixed resultsIn one Russian trial without placebo, anxiety eased about as much as with medazepam, a Valium-like drug7. Added to a similar drug, it did not clearly help at 2 weeks (40% vs 23% responders)8.For focus and memory in healthy people: UntestedNo placebo-controlled test of focus or memory in healthy people could be found. A 1996 study of 19 healthy men reported better work performance, but its summary mentions no placebo group1014.
FDAApproved in Russia as nose drops; not in US41516Approved in Russia as nose drops; not in US5610
US pharmaciesPharmacies may not make it1718Pharmacies may not make it101718
SportNot named; approved in Russia, so likely allowed41920Not named; unclear if a hormone ban covers it192021
AustraliaNot named in the Poisons Standard22Not named in the Poisons Standard22
Half-lifeMinutes34No human value found; lab and animal figures range from minutes to over an hour310
Taken asNasal drops (Russia’s 0.15% product; the form in the Russian studies that state a route)
Nasal spray (sold online and by US clinics, alone or blended with semax; no human data found on these products)
Subcutaneous injection, under the skin (sold online; no human data found)
Intraperitoneal injection, into the abdomen (animal studies only)		Nasal drops (Russia’s 0.1% and 1% products; every human study FDA found used the nose)
Nasal spray (sold by US clinics and online sellers; no human data found on these products)
Subcutaneous injection, under the skin (proposed for US compounding and sold online; no human data found)
Endonasal electrophoresis, a weak current that carries the drug into the nose lining (Russian eye studies and the 0.1% label)
Intraperitoneal (into the abdomen) or intravenous injection (animal studies only)
What it isA lab-made chain of 7 amino acids: tuftsin, a small peptide from the immune system, plus a proline-glycine-proline tail that helps it resist breakdown3.A lab-made chain of 7 amino acids: 4 from ACTH, the pituitary hormone that triggers cortisol release, plus the same proline-glycine-proline tail; its Russian label says it has no hormone activity35.
Sold in Russia forAnxiety, panic attacks, nervous exhaustion (neurasthenia), fatigue, unstable mood and sleep problems, as 0.15% drops sold without a prescription415.The acute phase of ischemic stroke (caused by a blocked blood vessel), as 1% drops; memory and thinking problems, recovery after stroke or brain injury and, from age 7, ADHD, as 0.1% drops; both need a prescription56.
Russian label rules it out inPregnancy, breastfeeding and anyone under 184.Anxiety disorders, acute psychiatric disorders, past seizures, pregnancy and breastfeeding, and anyone under 18 (1% drops) or under 7 (0.1% drops)56.
Strongest human evidenceThree small Russian studies in people with anxiety and related disorders (62, 60 and 70 patients) compared it with benzodiazepines or added it to one; none reported a placebo group, and the 70-patient study was partly funded by the company that holds selank’s Russian registration4789.A 2018 Russian study of 110 patients in rehabilitation after stroke: self-care scores (0 to 100) rose more with semax at 1 month (21.6 vs 11.3 points when rehabilitation started early); at 5 months the gains no longer differed in that early group but still did in a later-starting group; no placebo or blinding was reported11.
Placebo-controlled studiesOnly one found, in 52 healthy volunteers given selank, semax or placebo; it measured brain-scan patterns, not anxiety13.Two found, in 24 and 52 healthy volunteers; both measured brain-scan patterns at rest, not thinking or memory1323.
Biggest documented riskLittle safety data: FDA says it lacks important information on selank’s safety in people and that it may trigger immune reactions; its Russian label lists allergic reactions, including delayed ones1517.In rodents it strongly boosted amphetamine’s dopamine release, a response FDA links to drugs of abuse, and raised anti-clotting activity, a possible bleeding risk; FDA found no human data at all on injections under the skin1024.
Lab tests of gray-market vialsAlmost none: Finnrick, an independent testing service, lists a single selank test, from 3 August 2026, and it was incomplete25.5 Finnrick tests from 3 sellers between 12 March and 9 September 2026: 2 passed, 1 failed and 2 were incomplete26.
FDA advisers’ voteNo vote: selank was not on the agenda of the July 2026 meeting of FDA’s compounding advisers27.8 for, 5 against and 1 abstention on 24 July 2026 for letting pharmacies compound it, against FDA staff advice; FDA had not changed its compounding list as of 5 October 202610182728.

Has anyone studied selank and semax together?

Not as a pair: as of 7 October 2026, no study listed on PubMed has given the two together to people1. A 2020 brain-scan study, whose authors include N. F. Myasoedov, one of the two scientists who led the team behind both drugs, gave selank, semax or a placebo to separate groups of healthy volunteers313. Each peptide changed connections between the right amygdala, a fear-processing area, and part of the right temporal lobe13. In lab tests on human blood serum, both blocked enzymes that break down enkephalins, the body’s own opioid-like peptides29.

In a 2017 study of rats with a Parkinson’s-like brain injury, neither peptide changed movement, and the summary reports lower anxiety-like behavior only for selank2. Other rodent studies reviewed by FDA found anxiety-lowering effects for semax too10.

As of 7 October 2026, no trial of either one is registered on ClinicalTrials.gov3031. Blends are sold even so: in pages it viewed in December 2025, FDA found a US website offering a ‘50:50’ semax and selank blend as an injection and as a nasal spray10.

Questions people ask

Is selank or semax better for anxiety?

We found no published trial that compared them for anxiety1. Selank is the one Russia sells for anxiety, though its anxiety studies reported no placebo group, while semax’s Russian labels rule it out for people with anxiety disorders456789. In a 2017 rat study that tested both, only selank was reported to lower anxiety-like behavior2.

Which is better for focus, semax or selank?

Neither has been shown to sharpen focus or memory: the placebo-controlled studies in healthy volunteers measured brain-scan patterns, not thinking1323. Semax is the one Russia labels for memory and thinking problems, while selank’s label centers on anxiety46.

Can you take selank and semax together?

We found no study that gave the two together to people, so we cannot say whether the combination helps or what risks it adds1. FDA has found a ‘50:50’ blend sold in the US, and it says it lacks important safety information on each peptide alone1017.

Which is safer, selank or semax?

FDA says it lacks the information to judge the safety of either one in people17. It has flagged more specific concerns for semax, including possible abuse potential and bleeding risk from rodent studies, and one user’s report of eye pain with a hospital stay after semax nose drops10. Their Russian labels list few side effects: allergic reactions and an unpleasant taste for selank, mild nose irritation for semax515.

Go deeper

Sources

  1. 1PubMed search: selank AND semax (14 results; none gave the two together to people) National Library of Medicine (PubMed), accessed 7 Oct 2026. pubmed.ncbi.nlm.nih.gov
  2. 2Peptides semax and selank affect the behavior of rats with 6-OHDA induced PD-like parkinsonism Doklady Biological Sciences, May 2017. pubmed.ncbi.nlm.nih.gov
  3. 3A New Generation of Drugs: Synthetic Peptides Based on Natural Regulatory Peptides Neuroscience & Medicine (Scientific Research Publishing), Dec 2013. scirp.org
  4. 4Селанк (Selank) 0.15% nasal drops: instructions for use Vidal Russia drug reference, 22 Oct 2018. vidal.ru
  5. 5Семакс (Semax) 1% nasal drops: instructions for use Vidal Russia drug reference, 18 Mar 2021. vidal.ru
  6. 6Семакс (Semax) 0.1% nasal drops: instructions for use Vidal Russia drug reference, 17 Mar 2021. vidal.ru
  7. 7Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the therapy of generalized anxiety disorders and neurasthenia (in Russian) Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova, 2008. pubmed.ncbi.nlm.nih.gov
  8. 8Optimization of the treatment of anxiety disorders with selank (in Russian) Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova, 2015. pubmed.ncbi.nlm.nih.gov
  9. 9A comparison of the anxiolytic effect and tolerability of selank and phenazepam in the treatment of anxiety disorders (in Russian) Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova, 2014. pubmed.ncbi.nlm.nih.gov
  10. 10FDA Evaluation of Semax-Related Bulk Drug Substances (Semax (Free Base) and Semax Acetate), PCAC briefing document U.S. Food and Drug Administration, 11 May 2026. fda.gov
  11. 11The efficacy of semax in the tretament of patients at different stages of ischemic stroke (in Russian) Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova, 2018. pubmed.ncbi.nlm.nih.gov
  12. 12Effectiveness of semax in acute period of hemispheric ischemic stroke (a clinical and electrophysiological study) (in Russian) Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova, 1997. pubmed.ncbi.nlm.nih.gov
  13. 13Functional Connectomic Approach to Studying Selank and Semax Effects Doklady Biological Sciences, Jan 2020. pubmed.ncbi.nlm.nih.gov
  14. 14Synthetic ACTH analogue Semax displays nootropic-like activity in humans Neuroscience Research Communications, Sep 1996. doi.org
  15. 15Селанк (Selank) 0.15% nasal drops: instructions, doses, side effects RLS (Register of Medicinal Products of Russia), 15 Jul 2025. rlsnet.ru
  16. 16Nicholasville Compounding Pharmacy and Its Owner Sentenced for Unlawful Distribution of Prescription Drugs U.S. Attorney’s Office, Eastern District of Kentucky, 24 Feb 2021. justice.gov
  17. 17Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks U.S. Food and Drug Administration, 22 Apr 2026. fda.gov
  18. 18Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act (categories list) U.S. Food and Drug Administration, 14 May 2026. fda.gov
  19. 19World Anti-Doping Code International Standard: Prohibited List 2026 World Anti-Doping Agency, 24 Sep 2025. wada-ama.org
  20. 20World Anti-Doping Code International Standard: Prohibited List 2027 World Anti-Doping Agency, 21 Sep 2026. wada-ama.org
  21. 21Summary of Major Modifications and Explanatory Notes: 2027 Prohibited List World Anti-Doping Agency, 21 Sep 2026. wada-ama.org
  22. 22Therapeutic Goods (Poisons Standard—October 2026) Instrument 2026 (F2026L01327) Federal Register of Legislation, Australian Government, 28 Sep 2026. legislation.gov.au
  23. 23Effects of Semax on the Default Mode Network of the Brain Bulletin of Experimental Biology and Medicine, Sep 2018. pubmed.ncbi.nlm.nih.gov
  24. 24Semax, an ACTH(4-10) analogue with nootropic properties, activates dopaminergic and serotoninergic brain systems in rodents Neurochemical Research, Dec 2005. pubmed.ncbi.nlm.nih.gov
  25. 25Selank Safety Testing Results & Vendor Ratings Finnrick, 3 Aug 2026. finnrick.com
  26. 26Semax Safety Testing Results & Vendor Ratings Finnrick, 9 Sep 2026. finnrick.com
  27. 27July 23-24, 2026: Meeting of the Pharmacy Compounding Advisory Committee U.S. Food and Drug Administration, 6 Aug 2026. fda.gov
  28. 28The PEPTIDE-L Wave Rolls On! PCAC Adds Two More Bulk Drug Substances for the 503A List FDA Law Blog (Hyman, Phelps & McNamara), 28 Jul 2026. thefdalawblog.com
  29. 29Semax and selank inhibit the enkephalin-degrading enzymes from human serum (in Russian) Bioorganicheskaia Khimiia, May 2001. pubmed.ncbi.nlm.nih.gov
  30. 30ClinicalTrials.gov search for ‘selank’ (10 records, none mentioning selank) ClinicalTrials.gov, accessed 7 Oct 2026. clinicaltrials.gov
  31. 31ClinicalTrials.gov search for ‘semax’ (0 studies) ClinicalTrials.gov, accessed 7 Oct 2026. clinicaltrials.gov
  32. 32Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act (categories list updated 29 September 2023) U.S. Food and Drug Administration (copy hosted by the Alliance for Pharmacy Compounding), 29 Sep 2023. join.a4pc.org
  33. 33Unauthorized injectable peptide drugs seized and sold by Canada Peptide may pose serious health risks (RA-77807) Health Canada, 1 Aug 2025. recalls-rappels.canada.ca
  34. 34The occurrence of putative cognitive enhancing research peptides in seized pharmaceutical preparations: An incentive for controlling agencies to prepare for future encounters of the kind Drug Testing and Analysis, Mar 2020. pubmed.ncbi.nlm.nih.gov

Not medical advice. Neither compound is recommended here. How we grade evidence · Report an error.