Comparison
Selank vs TB-500
Side-by-side of Selank and TB-500. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.
Selank
Selank peptide benefits: tuftsin analog heptapeptide, intranasal anxiolytic and nootropic. Russian clinical data, dosing, half-life, safety.
TB-500
TB-500 peptide, a 17-aa thymosin beta-4 fragment. Preclinical tendon and wound healing via actin sequestration. Typical dosage 2 to 5 mg weekly. No human RCTs.
Effects at a glance
Selank
- •Synthetic heptapeptide analog of tuftsin developed in Russia in the 1990s
- •Approved in Russia for generalized anxiety disorder and asthenic conditions
- •Russian RCTs report anxiolytic effects comparable to medazepam without sedation or dependence
- •Modulates GABAergic and serotonergic signaling and BDNF expression in preclinical models
- •Most commonly administered intranasally; subcutaneous use is anecdotal
- •No Western-validated trials; not FDA approved; research-use-only outside Russia
TB-500
- •17-amino-acid fragment of endogenous Thymosin Beta-4, an actin-sequestering peptide
- •Preclinical models show accelerated tendon, ligament, and dermal wound healing
- •Equine veterinary use for soft-tissue injury is the most documented real-world application
- •Anecdotal human protocols use 2 to 5 mg twice weekly subcutaneously for 4 to 6 weeks
- •WADA banned under S2 (peptide hormones, growth factors) since 2018
- •No completed phase II or III human RCTs as of 2026; long-term safety unestablished
Side-by-side
| Attribute | Selank | TB-500 |
|---|---|---|
| Category | peptide | peptide |
| Also known as | TP-7, Tuftsin analog | Thymosin Beta-4 fragment, TB4-Frag, Thymosin Beta 4 |
| Half-life (hr) ↗ | 0.5 | 2 |
| Typical dose (mg) ↗ | 0.4 | 2.5 |
| Dosing frequency | 2-3x daily (intranasal) | 2x weekly (anecdotal protocols) |
| Routes | intranasal, subcutaneous | subcutaneous, intramuscular |
| Onset (hr) | 0.25 | - |
| Peak (hr) | 1 | - |
| Molecular weight | 751.85 | 4963.4 |
| Molecular formula | C33H57N11O9 | C212H350N56O78S |
| Mechanism | Modulates GABAergic, serotonergic, and dopaminergic signaling. Increases BDNF expression in hippocampal neurons in preclinical models. Modulates enkephalin levels and immune cytokine signaling via tuftsin-like activity. | Sequesters G-actin monomers, modulates cell migration and angiogenesis, and upregulates VEGF and myosin transcription. Promotes endothelial differentiation and stem-cell migration to injury sites in preclinical models. |
| Legal status | Approved as a prescription anxiolytic in Russia; not FDA approved; research-use-only grey market in most other jurisdictions | Not FDA approved; research-use-only grey market; banned by WADA |
| WADA status | unknown | banned |
| DEA / Rx | Not FDA approved; not scheduled; research-chemical status outside Russia | Not FDA approved; not scheduled; research-chemical status |
| Pregnancy | Not recommended; insufficient data | Insufficient data |
| CAS | 129954-34-3 | 885340-08-9 |
| PubChem CID | 11765600 | 62707662 |
| Wikidata | Q4416793 | Q7799921 |
Safety profile
Selank
Common side effects
- mild nasal irritation (intranasal)
- transient drowsiness (uncommon)
- mild headache
Contraindications
- pregnancy
- lactation
- severe psychiatric disorder (insufficient data)
Interactions
- benzodiazepines: additive anxiolytic effect; potential for over-sedation when stacked(moderate)
- SSRIs: no documented adverse interaction; co-administration described in Russian protocols(minor)
TB-500
Common side effects
- injection-site irritation
- fatigue (anecdotal)
- lethargy in early dosing (anecdotal)
Contraindications
- pregnancy
- active malignancy (theoretical angiogenic concern)
- no established human safety profile
Interactions
- BPC-157: Frequently co-administered in anecdotal healing protocols; no controlled interaction data(minor)
Which Should You Take?
Selank and TB-500 score evenly on the criteria we weight (goal breadth, legal accessibility, evidence depth). The conditionals below should drive the decision more than any aggregate score.
- → If your priority is focus or working memory, pick Selank.
- → If your priority is anxiety reduction, pick Selank.
- → If your priority is post-training recovery, pick TB-500.
- → If your priority is tendon repair, pick TB-500.
Edge case: Half-lives differ materially (Selank ~0.5 hr vs TB-500 ~2 hr). TB-500 reaches steady state faster; Selank is easier to dial in if tolerability is uncertain.
Default choice: either is defensible. Selank edges out on goal breadth + legal accessibility; TB-500 is the right call if your priority sits in the goals listed above.
This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.
Common questions
What is the difference between Selank and TB-500?
Selank and TB-500 differ in category (peptide vs peptide), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Selank or TB-500?
Selank half-life is 0.5 hours; TB-500 half-life is 2 hours.
Can you stack Selank with TB-500?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper