Don’t mix vitamin C with:
1. Alphahydroxy Acids (AHAs): Overloading your skin with too many acid based-ingredients (both vitamin C and AHAs are acid-based) increases your chances of redness, peeling and irritation. “Some AHAs even come with instructions to wash it off after a certain amount of time so that the skin can accommodate and tolerate it,” says Miami dermatologist Loretta Ciraldo, MD.
2. Copper Peptides: Copper peptides help to encourage elastin and collagen formation, making it necessary for wound healing. If used with vitamin C, the effects of each are neutralized.
3. Retinol: Many experts will say that super-strength concentrations of vitamin C and retinol ingredients shouldn’t be applied to the skin together, or only with extreme caution, since both are very powerful and can cause the skin to become dry. However, there are some topical products that contain both ingredients, but chances are they contain low concentrations of each, making them safe to use.
Don’t mix retinol with:
1. Benzoyl Peroxide: Retinol and benzoyl peroxide can ward off acne and prevent the formation of new blemishes, but when used simultaneously, they can counteract each other’s benefits. “Both are drying, exfoliating, peeling agents, and when they’re mixed together, they can cause excessive peeling, unwanted pigment, lasting redness and even blistering and scarring,” explains Seattle dermatologist Jennifer Reichel, MD.
2. AHAs: Both retinol and AHAs can help to generate new collagen, but be careful when using them together. “It’s okay to use both as long as you are not too sensitive to the combination,” says Dr. Ciraldo. “Most women with sensitive skin need to alternate, applying the AHA in the morning and retinol at night for the first few weeks so a tolerance can be built.”