Selank
| Category | Other Peptides |
| Goals | Cognition & Focus |
| Evidence level | Clinical (Russian clinical use; limited Western trials) |
| Legal status | Research-only in the US — registered prescription medicine in Russia |
| FDA status | Not FDA-approved; not currently on 503A bulk lists |
| Half-life | Plasma very short (~minutes); central effects reported to outlast it |
| Routes | Intranasal (most common) · Subcutaneous |
| CAS / MW / Sequence | 129954-34-3 · ~751.9 g/mol · TKPRPGP (7 aa) |
| Last reviewed | 2026-06-05 |
In one line
A synthetic heptapeptide analog of the immune peptide tuftsin, used in Russia as a prescription anxiolytic/nootropic and positioned as the calming counterpart to Semax.
Evidence at a glance
Selank has Russian clinical use (registered anxiolytic) and small trials reporting anti-anxiety effects comparable to low-dose benzodiazepines without sedation or dependence — but large independent Western RCTs are lacking. Treat enhancement claims cautiously. See Evidence Grading Explained and the Disclaimer.
Key Takeaways
- A synthetic heptapeptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro) built from the immunomodulatory tetrapeptide tuftsin (Thr-Lys-Pro-Arg) plus a stabilizing Pro-Gly-Pro tail.
- Developed as a peptide anxiolytic: reported anti-anxiety effects without the sedation, dependence, or withdrawal of benzodiazepines.
- Proposed to act via GABAergic modulation, effects on monoamines, and BDNF / enkephalin systems (mostly animal/early-clinical data).
- Registered in Russia; not FDA-approved in the US, where it is sold as a research chemical.
- Most commonly used intranasally; frequently paired with Semax.
What Is It
Selank is a synthetic heptapeptide developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. It is a stabilized analog of tuftsin, a naturally occurring tetrapeptide (Thr-Lys-Pro-Arg) with immunomodulatory activity, extended at the C-terminus with a Pro-Gly-Pro sequence to resist enzymatic degradation. It is marketed in Russia as a prescription anxiolytic with nootropic and immunomodulatory properties, intended to reduce anxiety without the characteristic drawbacks of benzodiazepine tranquilizers.
Mechanism of Action
Mechanisms are drawn from animal and early-clinical work:
- GABAergic modulation (animal/clinical) — proposed to influence GABA-A signaling and enhance the effect of benzodiazepines such as diazepam in stress models.
- Monoamine and enkephalin effects (animal evidence) — modulates serotonin metabolism and is reported to inhibit enkephalin-degrading enzymes, prolonging endogenous opioid peptide activity.
- BDNF / neurotrophic signaling (animal/in-vitro) — reported changes in BDNF expression, proposed to support nootropic effects.
- Immunomodulation (tuftsin-derived) — influences cytokine balance, consistent with its tuftsin lineage.
Limitations
Most mechanistic and clinical data originate from Russian research groups with limited independent Western replication. The exact primary molecular target is not fully established.
Evidence by Outcome
| Outcome | Evidence | Notes |
|---|---|---|
| Generalized anxiety / neurasthenia | Clinical | Russian trials report efficacy comparable to low-dose benzodiazepines, without sedation/dependence |
| Stress resilience | Clinical / Preclinical | Human and rodent stress-model data |
| Cognition / attention | Clinical / Anecdotal | Small studies; no Phase 2/3 enhancement RCTs |
| Mood / depression | Anecdotal / Preclinical | Mechanistically plausible; human data limited |
| Immunomodulation | Preclinical | Tuftsin-derived; cytokine effects in models |
Reported Dosing
Not medical advice
Protocols as reported in research and community sources. There is no established Western therapeutic dose for off-label use. See Reconstitution & Dosing Math.
| Route | Dose (reported) | Frequency | Cycle |
|---|---|---|---|
| Intranasal | ~300–500 µg/day (anxiety studies) | Split, 1–3× daily | Often 1–3 weeks |
| Subcutaneous | Reported anecdotally | 1× daily | Variable |
Pharmacokinetics
Selank has a very short plasma half-life (minutes), but reported central effects outlast measurable plasma levels — attributed to the protease-resistant Pro-Gly-Pro tail and downstream signaling changes. Intranasal delivery is favored for nose-to-brain transport and to bypass first-pass metabolism. Detailed human PK is not well established. See Half-Life & Pharmacokinetics.
Side Effects & Risks
- Reported as well tolerated in Russian clinical use, notably without benzodiazepine-type sedation, dependence, or withdrawal — but long-term and Western safety data are limited.
- Anecdotal: nasal irritation (intranasal route), mild fatigue or transient blood-pressure changes — not systematically documented.
- Sourcing risk: sold as a research chemical in the US, so identity and purity vary — see Sourcing and Red Flags & Scams.
- See Side Effects & Risk Management.
Cycling
No evidence-based cycling standard exists. Community protocols commonly run short courses (days to a few weeks). See Cycling.
Stacks It Appears In
- Frequently combined with Semax (a “calm focus” anxiolytic + nootropic pairing).
Comparisons
- Semax — Selank is the anxiolytic counterpart; Semax is the nootropic/neuroprotective peptide.
- Dihexa — a far more potent, preclinical-only synaptogenic peptide.
Sourcing & Quality
Outside Russia it is sold as a lyophilized “research chemical,” so identity and purity are not guaranteed. Evaluate quality before trusting a product: How to Read a CoA, Red Flags & Scams. Reconstitution and storage: Reconstitution & Dosing Math, Storage & Handling. No vendors are endorsed here.
Legal & Regulatory Status
(As of 2026-06-05.) Not FDA-approved for human use in the United States, where it is sold only as a research chemical; it is not currently listed among FDA 503A bulk substances prohibited from compounding. In Russia, Selank is a registered prescription anxiolytic. Status varies by country and it may be prohibited in tested sport. See Regulatory & Legal Status.
FAQ
Is Selank FDA-approved? No. It is not approved for human use in the US. It is a registered prescription drug in Russia.
Is Selank like a benzodiazepine? It is reported to produce comparable anxiety reduction at low benzodiazepine-equivalent levels but without the sedation, dependence, or withdrawal — though this comes mainly from Russian trials.
Why intranasal? The nasal route exploits nose-to-brain transport and avoids first-pass metabolism, suiting a short-lived peptide.
What is it usually paired with? Most often Semax, as a combined calm-and-focus protocol.
References
- Wikipedia — “Selank” (tuftsin lineage, sequence, Russian development).
- ProSpec / ChemicalBook — Selank CAS 129954-34-3, formula C33H57N11O9, molar mass ~751.9.
- Zozulya A.A. et al. — efficacy of the peptide anxiolytic Selank in generalized anxiety disorder and neurasthenia.
- Kolomin T. et al. (2018, Curr. Drug Targets / related) — molecular aspects of Selank activity; diazepam-potentiation rodent study (PMC5322660).
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