Side-by-side comparison of mechanisms, dosing, interactions, and stacking potential.
| GHK (without copper) | Melanotan II | |
|---|---|---|
| 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 subcutaneous injection during loading, reducing to 250 mcg 2-3 times weekly for maintenance. |
| Timing | Topical application morning and evening. Injectable in evening. | Administer 4-6 hours before UV exposure for optimal tanning synergy. Can be taken at any time of day. |
| Cycle Duration | Topical use can be ongoing indefinitely. Injectable cycles 8-12 weeks. | Loading phase 1-2 weeks, then maintenance as long as desired. Pigmentation fades gradually upon discontinuation. |
| 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.
Melanotan II is a synthetic cyclic analog of alpha-melanocyte-stimulating hormone (alpha-MSH) that non-selectively agonizes melanocortin receptors MC1, MC3, MC4, and MC5. MC1R activation stimulates eumelanin synthesis through tyrosinase upregulation, producing tanning. MC3R activation in the CNS increases libido and produces erectile responses. MC4R activation suppresses appetite. The cyclic structure provides enhanced in vivo stability (half-life 1-2 hours) and increased blood-brain barrier permeability compared to linear alpha-MSH.
Research indicates 250-500 mcg daily via subcutaneous injection during loading, reducing to 250 mcg 2-3 times weekly for maintenance.
Administer 4-6 hours before UV exposure for optimal tanning synergy. Can be taken at any time of day.
Loading phase 1-2 weeks, then maintenance as long as desired. Pigmentation fades gradually upon discontinuation.
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