A Guide to the Skincare Ingredients You Should Never Mix

When choosing new skincare products, it’s imperative to know which ones will mix and layer well together. Based on your skin type, it might be tricky to figure out which products complement each other the best, and you might go through some trial-and-error.  Here, Bougeoir guides you on your new skincare routine with a list of skincare ingredients that you should never mix together.


Oil and Water
First up is the most obvious combination we all know don't mix: oil and water. Oil repels water, so if you try to layer a water-based product over an oil-based product, like a balm, a film will be left on your skin that will prevent the water from absorbing. If you must use these two products in your routine, layer the oily product over the water-based one. But overall, stick to using water-based products and serums together.


Vitamin C and AHAs and BHAs
 AHAs and BHAs such as glycolic, salicylic, and lactic acids should never be used with Vitamin C.  Vitamin C is an acid, too, and is unstable, so the pH balance will be thrown off by layering these ingredients together and might as well be useless.


Retinol and Vitamin C
Retinol shouldn’t be used with Vitamin C either, because they’re both active ingredients. Retinol helps build collagen but it also creates skin cell turnover, so using it with an acid like Vitamin C can cause more irritation. Instead, use retinol at night and Vitamin C during the day. Retinol tends to work better with moisturizing ingredients like hyaluronic acid, ceramides, and SPF.


Vitamin C and Niacinamide
Niacinamide is found with Vitamin C in some multi-ingredient serums as antioxidants, but it’s never a good idea to layer them together. Both ingredients are helpful for improving acne, but used together, they can actually trigger breakouts and their helpful properties can be diminished. If you have to use them together, apply them at least 10 minutes apart.

AHAs and BHAs and Retinol
Retinol combined with these acids is a literal recipe for disaster, leaving your skin dry and irritated, since the main job of AHAs and BHAs is to exfoliate, which retinol already effectively does. It’s better to mix AHAs and BHAs with moisturizing ingredients and SPF.


Niacinamide and AHAs and BHAs
Niacinamide used with AHAs and BHAs together have no effect and can actually cause redness. Because niacinamide has a pH of around 5-7, it can actually raise the lower pH of the acids, which is around 3-4, and cancel out its properties. Used separately, both ingredients can help skin texture, acne, and signs of aging, so we encourage you to still use them.


Retinol and Benzoyl Peroxide
Benzoyl peroxide and retinol deactivate each other, so they should never be used together.
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