Selank
Selank (TKPRPGP) is a synthetic tuftsin analog anxiolytic developed in Russia that reduced generalized anxiety disorder symptoms in two Russian RCTs (Zozulya et al., 2008, PMID 19002092; Medvedev et al., 2007) without sedation or benzodiazepine-class side effects; Western replication is essentially zero, placing the entire evidence base under a -1.5 integrity adjustment.
Selank scored 6.5 / 10 (👍 Worth trying) on the BioHarmony scale as a Substance → Peptide.
What It Is
Selank (sequence TKPRPGP) is a synthetic heptapeptide developed at the Institute of Molecular Genetics, Russian Academy of Sciences, as a stabilized analog of tuftsin, the endogenous tetrapeptide immune regulator. The Gly-Pro C-terminal extension was added specifically to resist enzymatic degradation, extending its biological half-life for intranasal clinical use.
Type: Peptide (synthetic heptapeptide; tuftsin analog; gray-market).
Current status: Haven't tried.
Selank modulates GABA-A receptors, upregulates serotonin turnover, induces BDNF expression, and potentiates enkephalins. It is registered as a pharmaceutical in Russia for generalized anxiety disorder and neurasthenia, but is not approved by any Western regulatory body. Outside Russia it circulates as a gray-market research peptide administered by intranasal spray.
Terminology
- TKPRPGP: The amino acid sequence of Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro); the full molecular identity of the heptapeptide.
- Tuftsin: Endogenous tetrapeptide (TKPR) produced by the spleen; an immune modulator that activates macrophages, neutrophils, and monocytes.
- GABA-A: Gamma-aminobutyric acid type A receptor; the primary inhibitory ion channel in the CNS; target of benzodiazepines and Selank's anxiolytic mechanism.
- BDNF: Brain-Derived Neurotrophic Factor; a key neuroplasticity and neuroprotection signal involved in learning, memory, and antidepressant response.
- GAD: Generalized Anxiety Disorder; the primary indication studied in Selank's Russian RCTs.
- HPA axis: Hypothalamic-pituitary-adrenal axis; the central stress-response cascade; anxiolytics often modulate this indirectly.
- NNT: Number Needed to Treat; the inverse of absolute risk reduction; used to quantify clinical effect size.
- FAERS: FDA Adverse Event Reporting System; the US pharmacovigilance database consulted to check real-world safety signals.
📊 How BioHarmony Scoring Works
BioHarmony uses a weighted expected-value formula across 13 dimensions: 6 upside, 7 downside.> Selank calculation: > Upside: 1.925 / 5.00 > Downside: 1.190 / 5.00 (harm x1.4 + opportunity x1.0) > EV = 1.925 - 1.190 = 0.735 > Score = ((0.735 + 7) / 12) x 10 = 6.45 / 105.0/10 = neutral (benefits and risks are balanced). Above 5 = net positive. Below 5 = net negative.Harm-type downsides (Safety, Side Effects, Dependency, Reversibility) carry a 1.4x precautionary multiplier because harm weighs more than benefit. Opportunity-type downsides (Cost, Effort, Opportunity Cost) are subtracted at 1.0x.| Tier | Score | Meaning | |---|---|---| | ✅ Top-tier | 8.0+ | Do this yesterday | | 💪 Strong recommend | 7.0-7.9 | Worth prioritizing | | 👍 Worth trying | 5.8-6.9 | Good for the right person | | ⚖️ Neutral | 4.8-5.7 | Context-dependent | | ⚠️ Caution | 3.7-4.7 | Significant downsides to weigh | | 🚫 Skip | 0-3.7 | Not worth the risk |Not medical advice. For informational purposes only. Consult a qualified healthcare provider before using any intervention, particularly gray-market compounds without Western regulatory approval.
BioHarmony Engine v0.5
How this score is calculated →
Upside (1.93 / 5.00)
| Dimension | Weight | Score | Visual | Weighted |
|---|---|---|---|---|
| Efficacy | 25% | 3.2 | 0.800 | |
| Breadth of Benefits | 15% | 3.5 | 0.525 | |
| Evidence Quality | 25% | 1.5 | 0.375 | |
| Speed of Onset | 10% | 4.5 | 0.450 | |
| Durability | 10% | 2.5 | 0.250 | |
| Bioindividuality Upside | 15% | 3.5 | 0.525 | |
| Total | 2.925 |
Upside Rationale
Efficacy (3.2/5.0). Zozulya et al. (2008, PMID 19002092) demonstrated statistically significant reduction in Hamilton Anxiety Scale scores vs placebo over 14 days in approximately 80 GAD patients, with effect sizes in the small-to-moderate range (estimated d 0.4-0.6 based on reported mean score differences). Medvedev et al. (2007) placed Selank's anxiolytic potency as comparable to the benzodiazepine medazepam. The non-sedating, non-impairing profile is a genuine clinical differentiator from the benzodiazepine class. Modest secondary cognitive enhancement (attention, processing speed) was reported but not the primary measured outcome in either trial.
Breadth of Benefits (3.5/5.0). Selank touches at least four distinct biological systems with reasonable mechanistic evidence: (1) anxiolytic via GABA-A modulation, (2) mood via serotonin and BDNF pathways, (3) cognitive enhancement via BDNF-driven neuroplasticity (Vyunova 2018, PMID 29905936), and (4) immune modulation via tuftsin activity (Uchakina 2008, PMID 18924535). A fifth area, withdrawal management for opioid and alcohol dependency, has Russian clinical usage but sparse published data (Kolik 2014, PMID 25269426). The breadth is genuine but most endpoints beyond anxiety are secondary observations rather than primary trial endpoints.
Evidence Quality (1.5/5.0). The base tier is Tier 3 (small RCTs, controlled studies), which anchors near 3.0. However, a -1.5 integrity adjustment applies: evidence is entirely from Russian sources with no independent Western replication; there is no Cochrane review; Western ClinicalTrials.gov registrations are essentially absent; and the academic pipeline runs through a single national research institution. This is the single most significant limiting factor in the entire Selank scorecard. The mechanistic evidence from Semenova 2009 (PMID 19893853), Kasian 2010 (PMID 20677382), and Vyunova 2018 adds convergent biological plausibility but does not compensate for the absence of independent clinical replication.
Speed of Onset (4.5/5.0). Intranasal administration produces measurable anxiolytic effects within 15-60 minutes across Russian clinical reports and community accounts. The nasal mucosa provides rapid CNS access bypassing hepatic first-pass. This is among the fastest onset profiles of any non-prescription anxiolytic and is a practical advantage for situational and acute anxiety management.
Durability (2.5/5.0). Acute effect duration is 4-8 hours per dose. With repeated use, cumulative anxiolytic benefit builds over days to weeks, as shown by progressive Hamilton score improvement across the 14-day Zozulya course. However, benefits do not persist long after discontinuation; return-to-baseline is expected within days to weeks of stopping. This is not a structural neurological change intervention.
Bioindividuality Upside (3.5/5.0). Russian RCTs specifically enrolled GAD patients, a population with high baseline anxiety where anxiolytic responder rates were approximately 70-80%. In the broader biohacker/self-experimenter population with variable baseline anxiety, responder rates are likely lower. The anxious-responder phenotype is the primary beneficiary; calm-baseline users are unlikely to experience much effect. Immunomodulatory benefit is more broadly distributed but less clinically meaningful.
Downside (1.19 / 5.00)
| Dimension | Weight | Score | Visual | Weighted |
|---|---|---|---|---|
| Safety Risk | 30% | 2.0 | 0.600 | |
| Side Effect Profile | 15% | 2.0 | 0.300 | |
| Financial Cost | 5% | 2.0 | 0.100 | |
| Time/Effort Burden | 5% | 2.0 | 0.100 | |
| Opportunity Cost | 5% | 2.5 | 0.125 | |
| Dependency / Withdrawal | 15% | 2.0 | 0.300 | |
| Reversibility | 25% | 1.5 | 0.375 | |
| Total | 1.900 | |||
| Harm subtotal × 1.4 | 2.205 | |||
| Opportunity subtotal × 1.0 | 0.325 | |||
| Combined downside | 2.530 | |||
| Baseline offset (constant) | −1.340 | |||
| Effective downside penalty | 1.190 |
Downside Rationale
Safety Risk (2.0/5.0). No catastrophic risk floor trigger exists for Selank: no fatal adverse events, no organ failure signal, no serious AEs in published Russian trials. The intrinsic safety profile is benign within studied doses and durations. The gray-market supply chain introduces concentration accuracy and contamination risks that are extrinsic to the peptide itself (scored in Verdict, not here). The remaining intrinsic concern is the absence of Western pharmacovigilance data: FAERS has no Selank entries, WHO VigiBase has no meaningful signal, and long-term Russian post-market surveillance is not publicly accessible. Score 2.0 reflects a genuinely favorable profile with meaningful unknown-unknown risk from the data gap.
Side Effect Profile (2.0/5.0). Russian RCTs reported nasal irritation and transient fatigue as the primary adverse events, both mild and self-resolving. No psychomotor impairment, no sedation, no memory blunting, no rebound anxiety on cessation in clinical populations. Community experience largely confirms this tolerability profile. The profile compares very favorably to benzodiazepines (sedation, motor impairment, paradoxical disinhibition, dependency) and SSRIs (sexual dysfunction, GI effects, emotional blunting). Score 2.0 indicates low but not zero side effect burden.
Financial Cost (2.0/5.0). Gray-market nasal spray from established peptide vendors (e.g., Peptide Sciences, CosmicNootropic) runs approximately $30-60/month for typical 250-500 mcg/day use. This is accessible cost territory, comparable to mid-range supplements. Price varies with concentration, volume, and vendor. No prescription or clinical overhead cost required.
Time/Effort Burden (2.0/5.0). Administration requires 1-2 daily intranasal sprays taking under 30 seconds. No preparation, no injection, no titration protocol. The only effort element is sourcing from a reputable gray-market vendor, which is a one-time task.
Opportunity Cost (2.5/5.0). For the anxious user, Selank occupies the same niche as evidence-based alternatives: cognitive-behavioral therapy (gold-standard), SSRIs/SNRIs (strong evidence, FDA-approved), buspirone, and lifestyle interventions. Choosing gray-market Selank over CBT or a prescription with Western evidence backing carries a mild opportunity cost, particularly since CBT produces durable structural change and Selank does not. Score 2.5 reflects this trade-off without overstating it.
Dependency / Withdrawal (2.0/5.0). No addiction-type dependency has been documented. No classic benzodiazepine-style withdrawal syndrome has been reported in Russian trials or community experience. Some users report a brief period of heightened anxiety return on stopping after extended use, suggesting mild downregulation, but this is unformalized in the literature. Score 2.0 reflects a favorable dependency profile with a small caveat for potential mild adaptation with chronic daily use.
Reversibility (1.5/5.0). Selank is fully reversible on discontinuation. No permanent receptor changes, no structural neurological alteration, no long-term suppression of endogenous anxiolytic systems has been documented. Effects return to pre-intervention baseline within days of stopping. Score 1.5 (near-ideal reversibility) is warranted.
Verdict
Selank occupies a genuinely interesting niche: an acute non-sedating anxiolytic with plausible multi-pathway mechanism, real (if geographically narrow) clinical evidence, and a favorable tolerability profile versus benzodiazepines. The evidence quality score of 1.5/5.0 is not a judgment that Selank doesn't work. It is an honest accounting of the fact that the entire human evidence base comes from one national research ecosystem and has never been replicated by an independent Western group. That is a large epistemic gap.
For users comfortable with that gap, this is a low-risk, fast-acting, non-addictive anxiolytic worth exploring with appropriate sourcing discipline. For users who need Western-standard evidence, Selank is not there yet.
Supply chain note: gray-market peptide vendors vary substantially in concentration accuracy and sterility. Third-party-tested vendors with published certificates of analysis are strongly preferred.
✅ Best for: Acutely anxious individuals who have plateaued on lifestyle interventions and want a non-sedating, non-addictive anxiolytic; biohackers with high evidence-uncertainty tolerance exploring Russian neuropeptide pharmacology; users seeking a cognitive-preserving alternative to benzodiazepines for situational or performance anxiety; immune-health-conscious users who appreciate the tuftsin-class activity as a secondary benefit.
❌ Avoid if: You require FDA-approved or Western-RCT-backed evidence before using a compound; you are pregnant or breastfeeding (no safety data); you are using other GABAergic agents (additive effects unstudied); you have a history of nasal polyps or chronic sinusitis that may reduce intranasal absorption; you have mood disorders requiring primary antidepressant treatment (Selank is not a first-line or proven antidepressant).
Use Case Breakdown
The overall BioHarmony score reflects the intervention's primary evidence profile. These subratings are independent assessments per use case.
| Use Case | Score | Summary |
|---|---|---|
| 👍 Anxiety Primary | 6.5 | Primary indication with strongest evidence: two Russian RCTs (Zozulya 2008, Medvedev 2007) confirm GAD symptom reduction; non-sedating profile is a clinical differentiator. Evidence quality is weak by Western standards. |
| ⚖️ Mood / Emotional Regulation Primary | 5.5 | Mild antidepressant properties reported in Russian clinical observation; serotonin upregulation and BDNF are consistent with mood-elevating mechanism; not a primary indication. |
| 👍 Stress / Resilience Primary | 6.0 | Anxiolytic effect plus HPA-axis normalization makes Selank directly relevant to stress resilience; Russian RCTs used stress-related anxiety endpoints. |
| ○ Immune Function | 4.5 | Tuftsin is an endogenous immune peptide; Selank preserves this activity. Uchakina 2008 confirmed cytokine modulation and macrophage activation in human subjects. |
| ○ Cognition / Focus | 4.5 | Russian studies report modest attention and processing speed improvements as secondary endpoints; Medvedev 2007 noted preserved psychomotor function vs benzodiazepine comparator. |
| ○ Memory | 3.5 | BDNF upregulation (Vyunova 2018) is mechanistically linked to memory consolidation; limited direct memory endpoint data in humans. |
| ○ Depression | 3.5 | Mild antidepressant signal in Russian literature; insufficient evidence for a primary depression claim; likely adjunctive benefit only. |
| ○ Neuroplasticity | 3.5 | BDNF upregulation (Vyunova 2018, Kasian 2010) is a primary neuroplasticity driver; mechanistically plausible but no human neuroplasticity endpoint studies. |
| ○ Flow State / Peak Mental Performance | 3.5 | Non-sedating anxiolysis removing threat-response noise is a plausible flow-state enabler; user anecdotes support this; no formal flow-state measurement. |
| ○ HRV / Vagal Tone / Autonomic Balance | 3.5 | Anxiolytic effect is associated with improved HRV and vagal tone in general; no direct HRV measurement in Selank trials. |
| ○ Neuroprotection | 3.0 | BDNF induction and enkephalin potentiation suggest neuroprotective signaling; no direct neuroprotection RCT data. |
| ○ Sleep Quality | 3.0 | Anxiolytic effect may improve sleep onset latency in anxious individuals; no direct sleep-architecture endpoint data. |
| ○ Anti-Inflammatory | 3.0 | Tuftsin-class immunomodulation includes anti-inflammatory cytokine shifts (Uchakina 2008); not a primary anti-inflammatory agent. |
| ○ Energy / Fatigue | 3.0 | Anxiety reduction often improves perceived energy; no direct fatigue endpoint. Users report improved daytime energy without stimulation. |
| ○ Social Bonding / Empathy | 3.0 | Anxiety reduction removes social threat-response barriers; no direct social bonding endpoint. |
Frequently Asked Questions
How does Selank work in the brain?
Selank modulates GABA-A receptors to produce anxiolysis without full sedation, similar in principle to benzodiazepines but without the same receptor binding profile, as shown in Semenova et al. (2009, PMID 19893853). It also upregulates serotonin turnover, induces BDNF expression in hippocampal tissue, and potentiates endogenous enkephalins. Its tuftsin core (Thr-Lys-Pro-Arg) carries the immunomodulatory activity of the parent peptide. These multi-pathway effects are proposed to explain its combined anxiolytic, procognitive, and immune properties in Russian animal and human studies.
Is Selank effective for anxiety?
Russian RCTs support Selank's anxiolytic effect in generalized anxiety disorder. Zozulya et al. (2008, PMID 19002092) reported significant reduction in Hamilton Anxiety Scale scores compared to placebo over a 14-day course, while Medvedev et al. (2007) found comparable efficacy to the benzodiazepine medazepam without sedation. Both trials used small sample sizes (approximately 60-80 subjects) and were conducted exclusively in Russia with no independent Western replication, making the evidence base narrow despite being positive.
Does Selank cause sedation or cognitive impairment?
A key differentiator of Selank from benzodiazepines is the absence of sedation or psychomotor impairment at therapeutic doses, documented in Medvedev et al. (2007). Rather than blunting cognition, some Russian studies report modest improvements in attention and working memory as secondary endpoints. This non-sedating profile is attributed to its GABA modulation pattern differing from full GABA-A positive allosteric modulators. Community reports broadly confirm the awake, calm quality of effect, though formal cognitive battery comparisons to placebo in Western populations are lacking.
What is the recommended dose of Selank?
Russian clinical trials used 400-900 mcg/day delivered as a 0.15% nasal spray (approximately 100-150 mcg per actuation). In practice, 1-3 sprays per nostril once or twice daily delivers roughly 250-900 mcg total. A lower-strength 0.075% formulation is also available from gray-market peptide vendors for those preferring a gentler starting dose. Unlike Semax, Selank is less commonly cycled; some users report daily use for months without tolerance accumulation, though formal long-term studies do not exist.
How quickly does Selank work?
Selank produces noticeable anxiolytic effects within 15-60 minutes of intranasal administration, consistent across Russian clinical reports and community experience. Intranasal delivery bypasses first-pass hepatic metabolism and achieves rapid CNS penetration given the peptide's small molecular weight. On top of the acute effect, cumulative benefit builds over days to weeks of repeated use, with some subjects in Zozulya 2008 showing progressive Hamilton Anxiety Scale improvement across the 14-day trial. Acute effect duration is reported at 4-8 hours.
Is Selank safe for long-term use?
No serious adverse events were reported in Russian trials, and Selank has no known catastrophic risk profile (no fatal pancreatitis equivalent, no organ failure signal). The most common adverse events are nasal irritation and transient fatigue, both mild and reversible. No formal dependence or withdrawal syndrome has been documented, though the absence of Western long-term safety data means unknown risks cannot be ruled out. The gray-market supply chain introduces contamination and concentration accuracy risks that are independent of the peptide's intrinsic safety profile.
Can Selank be used for opioid or alcohol withdrawal?
Russian clinical experience includes use of Selank in opioid and alcohol withdrawal contexts, where its anxiolytic and immunomodulatory properties are hypothesized to ease the withdrawal syndrome. Formal published RCT data on this specific application is sparse and has not been replicated outside Russia. The mechanistic rationale (GABA modulation, enkephalin potentiation, stress-axis normalization) is plausible but the evidence does not meet the threshold for a definitive recommendation; it remains an area of Russian clinical practice rather than established evidence-based medicine.
What is the legal status of Selank?
Selank is a registered pharmaceutical in Russia (marketed as Selanc) but is not approved by the FDA, EMA, or MHRA. In the United States, it exists in a legal gray zone: not a controlled substance, not FDA-approved, and not explicitly banned, placing it alongside other research peptides. Possession for personal use carries minimal legal risk in most US states, but quality control from gray-market vendors varies substantially. EU and UK regulations vary; importation for personal use is generally tolerated but not explicitly legal. Always verify local regulations before purchasing.
How This Score Could Change
BioHarmony scores are living assessments. New research, regulatory changes, or personal context can shift the score up or down. These are the most likely scenarios that would change this intervention's rating.
| Scenario | Dimensions Changed | New Score |
|---|---|---|
| Western RCT confirms efficacy | Evidence 1.5 to 2.5 | 6.7 / 10 (👍 Worth trying) |
| Independent replication fails or safety signal emerges | Safety 2.0 to 3.0 | 6.0 / 10 (👍 Worth trying) |
| Multiple Western RCTs confirm efficacy and durability | Evidence 1.5 to 2.5, Efficacy 3.2 to 4.0, Durability 2.5 to 3.0, Bioind 3.5 to 4.0 | 6.9 / 10 (👍 Worth trying) |
| Long-term dependency or withdrawal signal documented | Dependency 2.0 to 3.5, Reversibility 1.5 to 2.5 | 5.7 / 10 (⚖️ Neutral) |
Key Evidence Sources
- Zozulya AA et al. (2008) — Selank in generalized anxiety disorder RCT vs placebo. Primary Russian RCT; 14-day trial; Hamilton Anxiety Scale primary endpoint
- Semenova TP et al. (2009) — Selank behavioral and neurochemical effects in rats. Animal model; GABA, serotonin, BDNF mechanism characterization
- Medvedev VE et al. (2007) — Selank vs medazepam in anxiety. Russian RCT; comparative trial vs benzodiazepine; non-sedating profile confirmed
- Uchakina ON et al. (2008) — Immunomodulatory effects of Selank. Tuftsin-class immune activity; cytokine modulation
- Kolik LG et al. (2014) — Selank and ethanol withdrawal in animal model. Animal study; withdrawal management rationale
- Kasian VS et al. (2010) — Selank effects on neuropeptide expression. Enkephalin system and BDNF induction mechanistic data
- Vyunova TV et al. (2018) — Selank and BDNF system. Recent mechanistic confirmation; BDNF pathway involvement
- Ashmarin IP et al. (1997) — Semax and Selank design rationale. Original peptide design paper from the Institute of Molecular Genetics
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See all ratings →📊 How BioHarmony scoring works
BioHarmony translates a weighted expected-value calculation into a reader-facing 0–10 score. 5.0 is neutral (benefits and risks balance). Above 5 = benefits outweigh risks; below 5 = risks outweigh benefits.
Harm-type downsides (safety risk, side effects, reversibility, dependency) carry a 1.4× precautionary multiplier. Harm weighs more than benefit. Opportunity-type downsides (financial cost, time/effort, opportunity cost) are subtracted at face value.
Use case subratings are independent assessments of how well the intervention addresses specific health goals. They are not components of the overall score. Each subrating reflects the scorer's judgment based on use-case-specific evidence, safety, and effect sizes.
Every dimension is evaluated on a 1–5 scale, and the baseline (1) is subtracted before weighting. A perfect intervention with zero downsides contributes zero penalty rather than a residual floor, so top-tier scores are actually reachable.
EV = Upside − Downside
EV = 1.925 − 1.190 = 0.735
EV ranges from −5 to +5. Adding 7 shifts to 2–12, dividing by 12 normalizes to 0–1, then ×10 gives the 0–10 score.
Score = ((0.735 + 7) / 12) × 10 = 6.5 / 10
