Skincare Ingredients You Shouldn’t Mix

The skincare products you use matter, as does the way you layer them on your skin. When it comes to your skin, more is not always better. Some active ingredients that are effective on their own can cause irritation or sensitivity when mixed.

Your skin is a delicate organ – it relies on you to take care of it. In this article, we’ll talk about the skincare ingredients you shouldn’t mix.


What it is: Niacinamide, or vitamin B3, is the form of vitamin B found in many skincare products. It helps calm acne, rosacea, hyper-pigmentation, and signs of aging.

Don’t mix with: vitamin C, glycolic acid, salicylic acid

Why: Niacinamide, on its own, is not irritating, meaning that it can mix with almost any ingredient in your skincare routine. However, when layered with vitamin C, the two become less effective.

When it comes to AHAs (glycolic acid) and BHAs (salicylic acid), mixing them with niacinamide can cause a severe red rash called a “niacin flush.”

What to use instead: You can still use niacinamide and vitamin C together if you wait at least 10 minutes between applying them. Niacinamide works well with retinol products like adapalene and tretinoin, so it’s typically best for nighttime routines. Vitamin C fights free radicals from sun damage, so it’s most effective during the day (be sure to finish with sunscreen).

AHAs/BHAs can be beneficial when used in the same routine as niacinamide. Apply them at different times of day to avoid redness and irritation. Make one product part of your morning routine and one product part of your night routine—but never apply them together.

Our Pick: The Ordinary Niacinamide, $5.90 (shop here)


What it is: Retinol is an alcohol derived from vitamin A. Two of the most well-known types are adapalene (Differin) and tretinoin. These products target acne, blackheads, skin texture, and signs of aging.

Don’t mix with: vitamin C, benzoyl peroxide, glycolic acid, salicylic acid

Why: Retinol is a favorite skincare ingredient of dermatologists the world over, but it’s also incredibly drying. Because glycolic acid and salicylic acid are exfoliants, they can exacerbate skin irritation when layered with retinol.

You can still use retinol and benzoyl peroxide together, but they may become less effective. According to some experts, retinol and benzoyl peroxide have opposing effects that cancel each other out when used together.

Vitamin C works during the daytime to protect from skin irritants, while retinol works overnight to restore collagen and elasticity.

What to use instead: For the best results, use your retinol in the evening and your vitamin C in the morning. While you should avoid mixing retinol and AHAs/BHAs, retinol works well with hydrating ingredients like hyaluronic acid and ceramides that counteract its drying effects.

Our Pick: Cerave Resurfacing Retinol Serum, $20 (shop here)

Vitamin C

What it is: Found as tetrahexyldecyl ascorbate and magnesium ascorbyl phosphate (or anything with that ‘ascorb-‘ root), vitamin C is a potent antioxidant that repairs and rehydrates skin. It brightens hyper-pigmentation and heals skin from the harmful effects of UV damage and pollution.

Don’t mix with: glycolic acid, salicylic acid

Why: Vitamin C and AHAs/BHAs are acidic, so they lower the skin’s pH. When used together, this is a recipe for dryness, redness, and irritation. However, if your skin is not sensitive, you may be able to tolerate them together. Before layering these ingredients on your face, test them on the inside of your wrist.

What to use instead: Vitamin C works beautifully with vitamin E and other antioxidants, which boost the protective and hydrating results you get from vitamin C. It’s also a great product to layer under your sunscreen in the morning since both protect against UV rays.

Our Pick: e.l.f. Beauty Shield Vitamin C Serum, $16 (shop here)


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