Side-by-side comparison of mechanisms, dosing, interactions, and stacking potential.
| GHK-Cu | PEG-MGF (Pegylated Mechano Growth Factor) | |
|---|---|---|
| Category | Growth Factors | Growth Factors |
| Standard Dose | Research indicates 1-2 mg daily via subcutaneous injection, or topical application at 1-3% concentration in cream/serum. | Research indicates 200-500 mcg administered 2-3 times per week via subcutaneous or intramuscular injection. |
| Timing | Evening administration preferred for skin rejuvenation (aligns with nocturnal repair cycles). Topical can be applied morning and evening. | On non-training days or several hours post-workout (to avoid competing with natural MGF pulse). Unlike native MGF, timing is more flexible due to extended half-life. |
| Cycle Duration | 8-12 weeks for injectable cycles. Topical use can be ongoing. | 4-8 week cycles. |
| Evidence Level | moderate_human | animal_plus_anecdotal |
GHK-Cu is a naturally occurring copper-binding tripeptide (glycyl-L-histidyl-L-lysine) that modulates gene expression affecting 31.2% of human genes. It activates Wnt/beta-catenin signaling for hair follicle growth, stimulates TGF-beta pathway for tissue remodeling, and promotes collagen and glycosaminoglycan synthesis while modulating metalloproteinase activity. The copper ion serves as a cofactor for enzymes essential to wound healing including superoxide dismutase and lysyl oxidase.
Research indicates 1-2 mg daily via subcutaneous injection, or topical application at 1-3% concentration in cream/serum.
Evening administration preferred for skin rejuvenation (aligns with nocturnal repair cycles). Topical can be applied morning and evening.
8-12 weeks for injectable cycles. Topical use can be ongoing.
PEG-MGF is the pegylated form of Mechano Growth Factor, where polyethylene glycol (PEG) molecules are covalently attached to protect against rapid enzymatic breakdown. This extends the half-life from 5-7 minutes (native MGF) to approximately 48-72 hours. Like native MGF, it activates satellite cell proliferation, promotes muscle fiber regeneration and hypertrophy, and supports tissue repair. The extended half-life allows for systemic distribution rather than purely local action, enabling subcutaneous rather than intramuscular administration.
Research indicates 200-500 mcg administered 2-3 times per week via subcutaneous or intramuscular injection.
On non-training days or several hours post-workout (to avoid competing with natural MGF pulse). Unlike native MGF, timing is more flexible due to extended half-life.
4-8 week cycles.
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 →