Can you use copper peptides with glycolic acid (AHA)?
It's better to use them at different times. AHAs need a low pH, while copper peptides have been shown to be stable closer to neutral, though direct evidence is limited.
Why
How tightly the GHK peptide holds its copper depends on pH, and lab testing confirmed copper tripeptide-1 (GHK-Cu) as stable between pH 4.5 and 7.4. AHA exfoliants work best at a lower pH than that, so layering them may loosen or break down some of the complex. No study has measured this on skin, so splitting them up is a cautious default rather than a proven need.
How to use them
Use copper peptides in the morning and your AHA at night, and wear broad-spectrum sunscreen during the day.
Sources
- 1GHK-Cu as a Bioactive Metallopeptide and Drug-Delivery Cargo: Coordination Chemistry, Formulation Science, Therapeutic Evidence, and a Translational Roadmap · Pharmaceutics, 2026
- 2Physicochemical characterization of native glycyl-l-histidyl-l-lysine tripeptide for wound healing and anti-aging: a preformulation study for dermal delivery · Pharmaceutical Development and Technology, 2016
- 3Fact-check: Why does pH matter for AHAs and BHAs? · Lab Muffin Beauty Science (Michelle Wong, PhD), 2014
General cosmetic information, not medical advice. Written with AI assistance from the sources above; updated October 2026.