Selank vs TB-500 (Thymosin Beta-4)

Side-by-side comparison of mechanisms, dosing, interactions, and stacking potential.

✅ Stacking Partners — These compounds are commonly used together and may have synergistic effects.
SelankTB-500 (Thymosin Beta-4)
CategoryPeptidesPeptides
Standard DoseResearch indicates 250-500 mcg daily via intranasal administration (0.15% solution, 2-3 drops per nostril).Research indicates 2-2.5 mg administered twice weekly via subcutaneous injection.
TimingCan be dosed morning through evening. Unlike Semax, Selank is calming and can be used at night.No strict timing requirements. Can be administered at any time of day. Systemic action means injection location is not critical.
Cycle Duration14-21 day cycles with equal rest periods.Loading phase: 4-6 weeks. Total cycle: 8-16 weeks.
Evidence Levelmoderate_humananimal_plus_anecdotal
A

Selank

Peptides

Mechanism

Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) is a synthetic heptapeptide analog of the immunomodulatory peptide tuftsin (from IgG heavy chain) with a Pro-Gly-Pro extension for metabolic stability. It allosterically modulates GABA-A receptors, enhancing GABA binding and GABAergic neurotransmission. Selank modifies mRNA levels of 84 genes involved in GABAergic neurotransmission in the frontal cortex, enhances enkephalinase inhibition (increasing endogenous enkephalin levels), and modulates serotonergic and noradrenergic systems to produce anxiolytic and nootropic effects.

Standard Dosing

Research indicates 250-500 mcg daily via intranasal administration (0.15% solution, 2-3 drops per nostril).

Timing

Can be dosed morning through evening. Unlike Semax, Selank is calming and can be used at night.

Cycle Duration

14-21 day cycles with equal rest periods.

Side Effects

  • Mild nasal irritation
  • Fatigue/sedation (uncommon)
  • Mild headache

Contraindications

  • Pregnancy and breastfeeding
  • Severe hepatic impairment

Best Stacking Partners

SemaxBPC-157Thymosin Alpha-1

Mechanism

TB-500 is a synthetic fragment of Thymosin Beta-4, a 43-amino acid protein that sequesters G-actin monomers, preventing premature polymerization and facilitating cellular migration and morphological changes essential for wound healing. It upregulates actin to promote cell migration, proliferation, and differentiation of stem/progenitor cells at injury sites. TB-500 also enhances angiogenesis, reduces inflammation, and promotes tissue remodeling through increased re-epithelialization and vascular density.

Standard Dosing

Research indicates 2-2.5 mg administered twice weekly via subcutaneous injection.

Timing

No strict timing requirements. Can be administered at any time of day. Systemic action means injection location is not critical.

Cycle Duration

Loading phase: 4-6 weeks. Total cycle: 8-16 weeks.

Side Effects

  • Temporary lethargy
  • Head rush upon injection
  • Injection site irritation
  • Mild headache

Contraindications

  • Active cancer (angiogenesis concern)
  • Pregnancy and breastfeeding
  • Recent myocardial infarction

Best Stacking Partners

BPC-157GHK-CuGH Secretagogues

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