Can you use vitamin C with glycolic acid (AHA)?
Yes, but it's gentler to use them at different times. Vitamin C in the morning and an AHA at night avoids stacking two acidic, potentially irritating steps.
Why
They don't cancel each other out; the issue is irritation. L-ascorbic acid serums need a pH below about 3.5 to absorb well, and AHAs also work at a low pH, so layering them adds up to more stinging, redness and dryness. AHAs can also increase sun sensitivity, which is another reason to keep them in the evening.
How to use them
Apply vitamin C in the morning before broad-spectrum sunscreen, and use your AHA at night. If your skin still feels irritated, use the AHA only a few nights a week.
Sources
- 1Topical L-ascorbic acid: percutaneous absorption studies · Dermatologic Surgery, 2001
- 2Alpha Hydroxy Acids · U.S. Food and Drug Administration, 2022
- 3Ultimate Vitamin C Skincare Guide Part 1: Ascorbic Acid · Lab Muffin Beauty Science (Michelle Wong, PhD), 2021
General cosmetic information, not medical advice. Written with AI assistance from the sources above; updated October 2026.