Pentadeca Arginate (PDA) vs Selank

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

Pentadeca Arginate (PDA)Selank
CategoryPeptidesPeptides
Standard DoseResearch indicates 250-500 mcg administered 1-2 times daily via subcutaneous injection.Research indicates 250-500 mcg daily via intranasal administration (0.15% solution, 2-3 drops per nostril).
TimingAdminister on an empty stomach. Inject near site of injury for localized effect.Can be dosed morning through evening. Unlike Semax, Selank is calming and can be used at night.
Cycle Duration4-12 weeks depending on therapeutic target.14-21 day cycles with equal rest periods.
Evidence Levelanimal_plus_anecdotalmoderate_human

Mechanism

Pentadeca Arginate is a synthetic 15-amino acid peptide utilizing an arginate salt formulation of the BPC-157 sequence, designed to enhance nitric oxide production and promote angiogenesis. It stimulates collagen synthesis, enhances tissue repair through increased tensile strength, reduces inflammation via modulation of inflammatory cytokines, and accelerates cellular proliferation in tendon fibroblasts. The arginate salt form provides superior stability and bioavailability compared to traditional acetate formulations.

Standard Dosing

Research indicates 250-500 mcg administered 1-2 times daily via subcutaneous injection.

Timing

Administer on an empty stomach. Inject near site of injury for localized effect.

Cycle Duration

4-12 weeks depending on therapeutic target.

Side Effects

  • Mild nausea (rare)
  • Injection site irritation
  • Headache (uncommon)

Contraindications

  • Active cancer
  • Pregnancy and breastfeeding
  • Children under 18

Best Stacking Partners

TB-500GHK-CuCJC-1295/Ipamorelin
B

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

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