Ingredients you shouldn’t combine

To make matters more confusing, you have to be careful about which ingredients you use together. Some ingredients cancel each other out, while other combinations can lead to irritation.

All skin types should avoid using the following ingredients at the same time:

• Vitamin C and benzoyl peroxide: Benzoyl peroxide oxidizes topical vitamin C, meaning it destroys all its fabulous skin benefits.

• Dapsone and benzoyl peroxide: Pairing these acne treatments can turn lighter and medium skin tones orange.

• Benzoyl peroxide and hydroquinone:Pairing these can also cause skin discoloration.

• Tretinoin and BHAs/AHAs: Tretinoin is a prescription strength retinoid and because of its high concentration, it can be irritating when mixed with face acids like BHA and AHAs.

The following combinations have been known to cause irritation for some people. To play it safe, we recommend that sensitive skin types and those prone to rosacea don’t use the following ingredients together. (And in general, should use these ingredients sparingly.)