Selank vs Sermorelin

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

SelankSermorelin
CategoryPeptidesPeptides
Standard DoseResearch indicates 250-500 mcg daily via intranasal administration (0.15% solution, 2-3 drops per nostril).Research indicates 200-300 mcg administered once daily at bedtime via subcutaneous injection.
TimingCan be dosed morning through evening. Unlike Semax, Selank is calming and can be used at night.Bedtime administration (aligns with natural nocturnal GH release). On empty stomach.
Cycle Duration14-21 day cycles with equal rest periods.12-24 week cycles. Some protocols use continuous treatment.
Evidence Levelmoderate_humanstrong_human
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
B

Sermorelin

Peptides

Mechanism

Sermorelin is a synthetic 29-amino acid peptide representing the biologically active fragment of GHRH (amino acids 1-29) with full functional activity. It activates GHRH receptors on pituitary somatotrophs, stimulating cAMP production via Gs protein/adenylate cyclase and MAP kinase pathways. Due to the interactive effects of sermorelin and endogenous somatostatin, GH release is episodic rather than continuous. Sermorelin also stimulates pituitary gene transcription of GH mRNA, increasing and preserving pituitary GH reserve.

Standard Dosing

Research indicates 200-300 mcg administered once daily at bedtime via subcutaneous injection.

Timing

Bedtime administration (aligns with natural nocturnal GH release). On empty stomach.

Cycle Duration

12-24 week cycles. Some protocols use continuous treatment.

Side Effects

  • Injection site reactions
  • Facial flushing
  • Headache
  • Dizziness
  • Transient taste changes

Contraindications

  • Active cancer
  • Pregnancy and breastfeeding
  • Intracranial hypertension

Best Stacking Partners

IpamorelinGHRP-2GHRP-6

Not sure which is right for you?

Take our free assessment to get personalized recommendations based on your health goals, current stack, and biomarkers.

Get Your Free Protocol →or take the assessment →