Benzoyl Peroxide.

"Benzoyl peroxide is one of the most popular anti-acne ingredients I recommend it all the time to my patients but it doesn't play nice with everything. These products work via oxidation, it's almost like they create a little mini chemical explosion on the skin, so you generally don't want to combine them with other ingredients or other products that are considered unstable or less stable and you don't want to combine them with antioxidants since they are prooxidant and are going to deactivate your antioxidant effects. You would want to avoid using benzoyl peroxide with things like retinol and prescription tretinoin since they're both very unstable, but adapalene, also known as Differin, is a third generation retinoid and it's very stable in the presence of benzoyl peroxide. So often when I'm counseling my acne patients and they want to be using two anti-acne things in one part of their routine I'm having them use benzoyl peroxide and adapalene together. That does have the potential to be irritating but they're not going to inactivate one another."

"benzoyl peroxide is a well-established acne treatment. Telling people to just get rid of their acne treatments without any kind of plan for them it's bad not only from the perspective of you now have people scared of a perfectly safe ingredient based on one study that wasn't peer-reviewed and has flaws in it, but you're also basically encouraging your audience to abandon a treatment without reminding them to talk to the person, AKA their physician or healthcare provider, who told them to use that treatment."

"A lot of people use this because they have acne whether that's blackheads or whiteheads and this can be fantastic for acne over the counter but a lot of people try to mix this with Benzoyl Peroxide or you're supposed to apply this to clean skin right so some people will wash their face with a Benzoyl Peroxide wash and then put this on while that's not a cardinal sin it's probably not a good idea if your skin isn't used to it. It's not a big no no it's not a red light it's kind of that yellow light it's like hey let's slow down if your skin is sensitive and if it's prone to dryness don't use Benzoyl Peroxide wash before washing this but if your doctor or derm recommends it or if you know that Benzoyl Peroxide and acids like salicylic acid work for your skin then proceed with caution."