Side-by-side comparison of mechanisms, dosing, interactions, and stacking potential.
| GHK (without copper) | GHRP-6 | |
|---|---|---|
| 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 100-300 mcg administered 1-3 times daily via subcutaneous injection. |
| Timing | Topical application morning and evening. Injectable in evening. | On empty stomach, 30+ minutes before meals. Bedtime dose most important. The strong hunger effect makes pre-meal timing practical. |
| Cycle Duration | Topical use can be ongoing indefinitely. Injectable cycles 8-12 weeks. | 8-16 week cycles. |
| 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.
GHRP-6 (Growth Hormone Releasing Peptide-6) is a synthetic hexapeptide that stimulates GH release through activation of the growth hormone secretagogue receptor (GHS-R1a/ghrelin receptor) on pituitary somatotrophs. It acts via dual sites — pituitary and hypothalamic — possibly involving regulatory factors beyond GHRH and somatostatin. GHRP-6 also stimulates ghrelin-mediated appetite signaling, increases cortisol and prolactin release, and has demonstrated cytoprotective properties including cardioprotection.
Research indicates 100-300 mcg administered 1-3 times daily via subcutaneous injection.
On empty stomach, 30+ minutes before meals. Bedtime dose most important. The strong hunger effect makes pre-meal timing practical.
8-16 week cycles.
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