Side-by-side comparison of mechanisms, dosing, interactions, and stacking potential.
| GHK (without copper) | Selank | |
|---|---|---|
| Category | Peptides | Peptides |
| Standard Dose | Research indicates 1-3% concentration in topical formulations. Injectable dosing follows GHK-Cu protocols at 1-2 mg daily. | Research indicates 250-500 mcg daily via intranasal administration (0.15% solution, 2-3 drops per nostril). |
| Timing | Topical application morning and evening. Injectable in evening. | Can be dosed morning through evening. Unlike Semax, Selank is calming and can be used at night. |
| Cycle Duration | Topical use can be ongoing indefinitely. Injectable cycles 8-12 weeks. | 14-21 day cycles with equal rest periods. |
| Evidence Level | moderate_human | moderate_human |
GHK (glycyl-L-histidyl-L-lysine) is a naturally occurring tripeptide found in human plasma, saliva, and urine that has an extremely high affinity for copper(II) ions. Even without exogenously complexed copper, GHK rapidly chelates available copper in biological systems, making copper-free GHK functionally similar to GHK-Cu in vivo. The peptide stimulates collagen and glycosaminoglycan synthesis, modulates metalloproteinase activity, resets gene expression patterns toward a healthier state (affecting 31.2% of human genes), and activates wound healing cascades.
Research indicates 1-3% concentration in topical formulations. Injectable dosing follows GHK-Cu protocols at 1-2 mg daily.
Topical application morning and evening. Injectable in evening.
Topical use can be ongoing indefinitely. Injectable cycles 8-12 weeks.
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.
Research indicates 250-500 mcg daily via intranasal administration (0.15% solution, 2-3 drops per nostril).
Can be dosed morning through evening. Unlike Semax, Selank is calming and can be used at night.
14-21 day cycles with equal rest periods.
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 →