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)
A lipopeptide used in topical skincare that stimulates collagen and fibronectin production in the skin. One of the most studied cosmetic peptides, marketed as Matrixyl. Works by mimicking a collagen fragment that signals fibroblasts to produce new collagen matrix. Widely used in anti-aging serums and creams.
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.
The KTTKS sequence mimics a collagen breakdown fragment (matrikine) that signals fibroblasts to initiate new collagen synthesis. The palmitoyl group enhances skin penetration by increasing lipophilicity. Stimulates production of collagen types I, III, and IV, as well as fibronectin and glycosaminoglycans.
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.
- Anti-wrinkle topical treatment
- Collagen stimulation in aging skin
- Skin firmness and elasticity improvement
- Post-procedure skin recovery
- Cosmeceutical formulations
- Skin rejuvenation and anti-aging
- Wound healing
- Hair growth stimulation
- Collagen production
- Reducing inflammation
- Generally well-tolerated topically
- Mild skin irritation in sensitive individuals
- Efficacy depends on formulation and concentration
- Not effective via injection — topical only
- Results require consistent use over weeks
- Generally well-tolerated topically
- Injectable form has less safety data
- Potential copper toxicity at high doses
- Skin irritation possible with topical use
Not regulated as a drug by the FDA. Classified as a cosmetic ingredient. No prescription required. Available in over-the-counter skincare products. No FDA review process for cosmetic peptides.
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.