Compare Peptides
Select any two compounds for a side-by-side comparison of mechanism, uses, risks, and FDA regulatory status.
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GHK-Cu
Copper Peptide, Glycyl-L-histidyl-L-lysine:copper(II)
A synthetic analog of alpha-MSH that acts on melanocortin receptors. Originally developed at the University of Arizona as a potential tanning agent, it gained notoriety for potent sexual arousal and appetite suppression effects.
A naturally occurring copper-binding tripeptide found in human plasma, saliva, and urine. Levels decline significantly with age. Widely used in both injectable and topical forms for anti-aging.
Activates MC1R (melanocortin 1 receptor) to stimulate melanin production. Also activates MC3R and MC4R, which mediate sexual arousal, appetite suppression, and cardiovascular effects. The MC4R activation is primarily responsible for its erectile and libido-enhancing properties.
Activates wound healing genes, promotes collagen and elastin synthesis, stimulates blood vessel growth, and has anti-inflammatory and antioxidant properties. The copper ion is essential for many enzymatic processes in tissue remodeling.
- Skin tanning
- Sexual dysfunction treatment
- Libido enhancement
- Erectile dysfunction (investigational)
- Skin rejuvenation and anti-aging
- Wound healing
- Hair growth stimulation
- Collagen production
- Reducing inflammation
- Nausea and vomiting (common)
- Facial flushing
- Spontaneous and prolonged erections
- Melanocyte stimulation may activate existing moles or nevi
- Potential cardiovascular effects
- High abuse potential from gray market
- Very limited controlled clinical trial data
- Generally well-tolerated topically
- Injectable form has less safety data
- Potential copper toxicity at high doses
- Skin irritation possible with topical use
Removed from FDA 503A Category 2 effective April 22, 2026. Scheduled for PCAC review before February 2027. One of the more controversial compounds on the list due to its widespread gray-market use and safety concerns. Compounding not yet authorized — status is in regulatory gray zone pending PCAC recommendation.
PCAC: By February 2027
GHK-Cu has a notably complex status after the April 15, 2026 FDA announcement. Injectable GHK-Cu is being removed from Category 2 (significant safety risks), while non-injectable GHK-Cu is simultaneously being removed from Category 1 (active evaluation). Both forms are scheduled for a unified PCAC review before February 2027. Topical cosmetic use is unaffected. Injectable use is now in regulatory gray zone — compounding pharmacies should not assume authorization until PCAC acts.
PCAC: By February 2027
This comparison is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any peptide therapy.