Selank vs Semax
Two Russian heptapeptides out of the same research tradition, split by target: Selank was studied for anxiety, Semax for stroke and cognition. Neither has Western trial data.
Short answer
Both have human clinical data behind them, which makes the goal the real difference between Selank and Semax. For a reader focused on anxiety and focus, Selank is the relevant choice; Semax is marketed for cognition, focus and neuroprotection. Selank matched benzodiazepines on anxiety in small Russian trials (n=62 vs medazepam), none described as randomized.
Selank
A GABA-modulating anxiolytic that matched benzodiazepines in small Russian trials; the mechanism is credible but the evidence base is thin and single-country.
Full Selank evidence reviewSemax
A BDNF-raising ACTH(4-10) analog registered as a drug in Russia — but the human evidence is small, single-country and mostly uncontrolled.
Full Semax evidence reviewSelank vs Semax: head to head
- FDA status / approved use
Selank
Reportedly past Phase III in Russia; not FDA-approved; sold in the US as a research peptideSemax
Registered drug in Russia; not FDA-approved- Marketed for
Selank
Anxiety, focusSemax
Cognition, focus, neuroprotection- Outcome areas
Selank
Mood / anxiety / stress; Cognitive function / memorySemax
Cognitive function / memory- Evidence grade
Selank
Clinical dataSemax
Clinical data- How it works
Selank
Modulates the GABA system without acting as a benzodiazepineSemax
ACTH(4-10) analog without hormonal activity that raises brain BDNF in animal studies- Route and dosing
Selank
Nasal spray (intranasal)Semax
Intranasal- Headline human result
Selank
Matched benzodiazepines on anxiety in small Russian trials (n=62 vs medazepam), none described as randomizedSemax
Not established- Strongest evidence
Selank
Medvedev, Korsakov J 2015Selank evidence reviewPubMed 26356395Semax
Semax MND trial, Korsakov J 2007Semax evidence reviewPubMed 18379501- Key safety signal
Selank
No large human safety database; lab work showed anti-clotting activity, a theoretical bleeding concernSemax
Robust and long-term human safety data are essentially absent- How it is obtained
Selank
Sold gray-market as a research chemical; no approved or legitimately compounded human productSemax
Sold gray-market as a research chemical; no approved or legitimately compounded human product
| Selank | Semax | |
|---|---|---|
| FDA status / approved use | Reportedly past Phase III in Russia; not FDA-approved; sold in the US as a research peptide | Registered drug in Russia; not FDA-approved |
| Marketed for | Anxiety, focus | Cognition, focus, neuroprotection |
| Outcome areas | Mood / anxiety / stress; Cognitive function / memory | Cognitive function / memory |
| Evidence grade | Clinical data | Clinical data |
| How it works | Modulates the GABA system without acting as a benzodiazepine | ACTH(4-10) analog without hormonal activity that raises brain BDNF in animal studies |
| Route and dosing | Nasal spray (intranasal) | Intranasal |
| Headline human result | Matched benzodiazepines on anxiety in small Russian trials (n=62 vs medazepam), none described as randomized | Not established |
| Strongest evidence | Medvedev, Korsakov J 2015Selank evidence reviewPubMed 26356395 | Semax MND trial, Korsakov J 2007Semax evidence reviewPubMed 18379501 |
| Key safety signal | No large human safety database; lab work showed anti-clotting activity, a theoretical bleeding concern | Robust and long-term human safety data are essentially absent |
| How it is obtained | Sold gray-market as a research chemical; no approved or legitimately compounded human product | Sold gray-market as a research chemical; no approved or legitimately compounded human product |
marks a row where the two differ. “Not established” marks a cell the available evidence does not answer. Evidence grades come from our evidence matrix, which grades each molecule on the human data for the use it is marketed for.
- Clinical data:
- Tested in humans — but investigational, discontinued, or proven only on a surrogate marker (not the marketed outcome).
Our verdict
Both sit in the same evidentiary spot: real human studies that are small, single-country, and mostly uncontrolled or non-randomized, with no large Western double-blind trial for either. Selank's edge is that its trials put it directly against benzodiazepines; Semax's is a better-worked-out BDNF and dopamine mechanism plus decades of Russian clinical use. Neither is FDA-approved, and what is sold in the US is unregulated research-only material rather than the trialed drug. They have never been compared with each other.
Selank fits if
Selank is the closer fit if your question is anxiety, since its small Russian trials at least measured it against benzodiazepines.
Semax fits if
Semax is the closer fit if the interest is cognition, stroke recovery, or neuroprotection, where its BDNF mechanism and Russian clinical use sit.
Selank vs Semax: common questions
- Is either Selank or Semax FDA-approved?
- No. Selank is reportedly past Phase III in Russia; not FDA-approved; sold in the US as a research peptide. Semax is a registered drug in Russia; not FDA-approved.
- Which has stronger human evidence, Selank or Semax?
- Neither clearly. Both have human clinical data. The key source for Selank is Medvedev, Korsakov J 2015; for Semax, it is Semax MND trial, Korsakov J 2007.
- What are the main safety concerns with Selank and Semax?
- Selank has no large human safety database; lab work showed anti-clotting activity, a theoretical bleeding concern. With Semax, robust and long-term human safety data are essentially absent.
Key studies behind each
Selank
- Vyunova TV, Andreeva L, Shevchenko K, et al. (2018). Peptide-based Anxiolytics: The Molecular Aspects of Heptapeptide Selank Biological Activity. Protein Pept Lett. PubMed 30255741
- Volkova A, Shadrina M, Kolomin T, et al. (2016). Selank administration affects the expression of some genes involved in GABAergic neurotransmission. Front Pharmacol. PubMed 26924987
- Zozulya AA, Kost NV, Sokolov OYu, et al. (2001). The inhibitory effect of Selank on enkephalin-degrading enzymes as a possible mechanism of its anxiolytic activity. Bull Exp Biol Med. PubMed 11550013
- Doyno CR, White CM. (2021). Sedative-Hypnotic Agents That Impact Gamma-Aminobutyric Acid Receptors: Focus on Flunitrazepam, Gamma-Hydroxybutyric Acid, Phenibut, and Selank. J Clin Pharmacol. PubMed 34396551
Semax
- Dolotov OV, Karpenko EA, Inozemtseva LS, Seredenina TS, et al. (2006). Semax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampus. Brain Res. PubMed 16996037
- Tsai SJ. (2007). Semax, an analogue of adrenocorticotropin (4-10), is a potential agent for the treatment of attention-deficit hyperactivity disorder and Rett syndrome. Med Hypotheses. PubMed 16996699
- Levitskaya NG, Sebentsova EA, Andreeva LA, Alfeeva LY, et al. (2004). The neuroprotective effects of Semax in conditions of MPTP-induced lesions of the brain dopaminergic system. Neurosci Behav Physiol. PubMed 15341218
- Serdiuk AV, et al. (2007). Open-label clinical trial of Semax in the treatment of motor neuron disease. Zh Nevrol Psikhiatr Im S S Korsakova. PubMed 18379501
The full evidence reviews
- Selank: a non-benzodiazepine anxiolytic peptide, lightly tested
A tuftsin-analog heptapeptide that modulates GABA without being a benzodiazepine — and matched benzodiazepines in small Russian trials. The mechanism is credible; the evidence base is thin.
Updated August 2026
- Semax: a real Russian nootropic with an under-tested evidence base
An ACTH(4-10)-derived heptapeptide that raises BDNF and is a registered drug in Russia. The mechanism is credible — but the human evidence is small, single-country, and mostly uncontrolled.
Updated August 2026
Where to get it
Where to get peptide therapy
Clinician-led telehealth services that prescribe compounded peptides. The specific peptides offered vary by provider — confirm Selank availability before ordering.
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