Compare Peptides
Select any two compounds for a side-by-side comparison of mechanism, uses, risks, and FDA regulatory status.
Popular comparisons
GHK-Cu
Copper Peptide, Glycyl-L-histidyl-L-lysine:copper(II)
Bioactive peptide fragments derived from hydrolyzed collagen protein. The most commercially successful peptide supplement category, with a global market exceeding $5 billion. Available in Types I, II, III, and marine-sourced variants.
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.
Provides bioavailable proline, glycine, and hydroxyproline — amino acids critical for collagen synthesis. Dipeptides (Pro-Hyp, Hyp-Gly) are absorbed intact and stimulate fibroblast activity, promoting endogenous collagen production in skin, joints, and connective tissue.
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 elasticity and hydration
- Joint health and mobility
- Hair and nail strength
- Gut lining support
- Bone density support
- Skin rejuvenation and anti-aging
- Wound healing
- Hair growth stimulation
- Collagen production
- Reducing inflammation
- Generally well-tolerated
- Mild GI discomfort in some users
- Allergic reactions (rare, especially marine-sourced)
- Heavy metal contamination risk in low-quality products
- Efficacy debated — some studies industry-funded
- Generally well-tolerated topically
- Injectable form has less safety data
- Potential copper toxicity at high doses
- Skin irritation possible with topical use
Classified as a dietary supplement under DSHEA. Not FDA-approved for any medical indication. Widely available OTC without prescription. No regulatory restrictions.
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.