GHK-Cu (Copper Peptide) vs Retatrutide

A detailed comparison to help you understand the differences and choose the right peptide for your research goals.

GHK-Cu (Copper Peptide)

GHK-Cu is a naturally occurring copper peptide found in human plasma, saliva, and urine. It plays important roles in wound healing, tissue repair, and has shown anti-aging properties in research.

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Retatrutide

Retatrutide is an investigational triple agonist targeting GIP, GLP-1, and glucagon receptors. Phase 2 trials showed unprecedented weight loss of up to 24% at 48 weeks, making it potentially the most effective obesity treatment studied.

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Side-by-Side Comparison

AspectGHK-Cu (Copper Peptide)Retatrutide
MechanismAttracts immune cells and fibroblasts to wound sites, stimulates collagen and glycosaminoglycan synthesis, promotes angiogenesis, and has antioxidant effects. Modulates gene expression related to tissue repair.Triple receptor activation provides complementary metabolic effects: GLP-1 and GIP reduce appetite and improve insulin sensitivity, while glucagon receptor activation increases energy expenditure and promotes hepatic fat oxidation.
Typical DosageTopical: Applied as serum or cream 1-2 times daily. Injectable: 1-2mg daily for research purposes. Microneedling protocols often use 0.5-1%.Clinical trials used doses from 1mg to 12mg weekly. Optimal dosing still being determined in ongoing Phase 3 trials.
AdministrationMost commonly used topically for skin applications. Can be injected subcutaneously for systemic effects. Often combined with microneedling for enhanced skin penetration.Subcutaneous injection once weekly. Currently only available through clinical trials - not yet FDA approved.
Side EffectsTopical use is generally well-tolerated. May cause temporary skin irritation or redness in sensitive individuals. Injectable use may cause injection site reactions.Similar GI effects to other incretin-based therapies: nausea, diarrhea, vomiting, constipation. Dose-dependent severity.
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Key Differences

Unique to GHK-Cu (Copper Peptide):

Unique to Retatrutide:

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