Can I use glycolic acid with vitamin C?
You can use both in one routine. The useful question is whether they belong in the same sitting, and the answer depends on which vitamin C you have.
Yes, at different times. Glycolic acid and pure ascorbic acid both work at a low pH, and two low pH products in one sitting is a lot for one face. Neither cancels the other, so the reason to separate them is comfort: vitamin C in the morning, glycolic acid at night. A stabilised vitamin C derivative makes this matter less.
Why they suit one routine
Glycolic acid works at the surface, loosening the bonds between dead cells so they shed more evenly. It suits dullness, rough texture and surface pigmentation. Vitamin C is an antioxidant: it deals with the reactive molecules that form when skin meets daylight, and it works upstream of pigment on the signalling that provokes it. Different jobs, so a routine can reasonably want both.
Why not the same sitting
Pure ascorbic acid needs a low pH to get into the skin, which is why it tingles. Glycolic acid is the smallest exfoliating acid, so it penetrates furthest and irritates most. Two low pH products in one sitting is tolerable for some skin and unpleasant for plenty, and the barrier pays for the overlap. Nothing is cancelled. The cost is comfort.
Morning and night
- Vitamin C in the morning, on clean dry skin, with sunscreen on top. Daylight is what its antioxidant work defends against.
- Glycolic acid at night, two or three nights a week at most, which is enough for most people on a leave-on acid.
- If your skin is already talking back, alternate days instead.
- Sunscreen every morning matters more, not less, once you exfoliate.
Which vitamin C you have changes the answer
Pure L-ascorbic acid is the one that needs a low pH and stings, so it is the one to keep away from glycolic acid. Ethyl ascorbic acid is a derivative that does not need the low pH, and the salts sold as SAP and MAP are stable near neutral and gentle. With one of those, using vitamin C on an acid evening is more realistic, though the exfoliation still counts towards what your skin can take in a week.
Lactic acid, and acids in a wash
The same answer applies to lactic acid, which is gentler and holds water as well. A glycolic acid face wash is a smaller step than a leave-on, because it is rinsed off, so vitamin C after a glycolic wash is easier than after a glycolic serum or toner. Count it anyway if your skin is sensitive.
Cham makes no glycolic acid product. Vitamin C in the range is the two stabilised forms in the Brightening Face Mask, alongside alpha arbutin and niacinamide. Keep the mask for a night without glycolic acid.
This page describes how ingredients behave together. It does not diagnose. A prescriber, a pregnancy, or a diagnosed skin condition outranks anything written here.
Related questions
Which goes first, glycolic acid or vitamin C?
Ideally neither, because they belong in different sittings. If you do use both in one evening, for example with a gentle vitamin C derivative on skin already used to acids, apply the acid first on clean dry skin, let it dry, then the vitamin C, then a moisturiser.
Can glycolic acid and vitamin C make dark spots worse?
Irritation can. Glycolic acid is the most irritating of the exfoliating acids, and on deeper skin tones its irritation can leave marks of its own. That is the main reason not to stack it with a low pH vitamin C.
Does the same apply to lactic acid?
Yes. Lactic acid is gentler than glycolic acid and holds water as well as exfoliating, so it is easier on dry or sensitive skin, but it is still a low pH exfoliant and the same timing applies.