skincare ingredients to never use together

Skincare ingredients can be such divas.

All the best anti-aging superstars do wonders on their own but ask them to collaborate and they throw a tantrum. They just won’t do their best work. So frustrating!

Wonder who these prima donnas are? Here are the skincare ingredients you should never mix (and how you can force them to get along if you must):

never mix retinol with aha bhs

Retinol + AHAs/BHA

AHAs (glycolic and lactic acid) and BHA (salicylic acid) are all powerful exfoliants. Retinol (a form of vitamin A), can accelerate cellular turnover (that’s scientific lingo for speeding up your skin’s natural exfoliating process).

All these ingredients help you get rid of the old, dull, and damaged cells on the surface of your skin and replace them with new, bright, and healthy ones.

When used on their own, that is. When used together, they’re more likely to cause redness and irritations. Oh, they can make your skin much more sensitive to sunlight, too.

This combo is proof that too much of a good thing is a bad thing.


  • Use them at different times of the day or week. I use glycolic acid and retinol on alternate nights. But you can exfoliate in the AM and use retinol at night, too.

Related: AHAs VHS BHA: Which One Should You Use?

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never mix retinol with benzoyl peroxide

Retinol + Benzoyl Peroxide

Did you know that retinol can treat acne, too? So does benzoyl peroxide. It has a peeling action that keeps the pores clean and kills the bacteria that cause acne.

But, benzoyl peroxide is very harsh on its own. That’s why it’s more of a last resort treatment to be used on pimples only.

Use it together with retinol and it gets even harsher. Expect flakiness, redness, peeling, and irritation. Do you really wanna take the risk?


  • Choose one!
  • If you only get the odd, stubborn pimple, you can apply benzoyl peroxide only on the annoying bugger, and retinol everywhere else. But give other pimple-busters, like salicylic acid or sulfur, a chance first.

Related: Salicylic Acid VS Benzoyl Peroxide: Which One Should You Choose?

never mix retinol with vitamin c

Retinol + Vitamin C

Retinol and vitamin C are my two all-time fave ingredients. They’re both so powerful: they fight free radicals, boost the production of collagen, and brighten skin.

But, they don’t play well together. Retinol works best at a pH of 5.5-6. Vitamin C (in the pure form of l-ascorbic acid) needs a pH of 3.5 or lower. You see the problem?

It’s tricky to formulate a product at a pH that’ll satisfy both vitamin C and retinol. But, that doesn’t mean they’re useless together (there are so many great products out there that contain both). They still work, just not to their full potential.


  • Use these ingredients at different times of the day or week.
  • Choose time-released products. This simply means that retinol is put into a capsule and released slowly into the skin over a period of several hours. Vitamin C is delivered all at once. So, long after that’s being absorbed, retinol is still being pumped into your skin, finding nothing in its path that can deactivate it.
  • Go for another form of vitamin C. Magnesium ascorbyl palmitate,for example, has an optimal pH of 7-8.5, so it can easily be formulated with retinol, without compromising on efficacy.

Related: Types Of Vitamin C In Skincare Products

never mix vitamin c with niacinamide

Niacinamide + Vitamin C

A quick Google search will highlight two problems with this combo:

  1. Niacinamide turns Vitamin C yellow, making it ineffective.
  2. Mixing Niacinamide with Vitamin C turns it into Niacin, a substance that can have temporary flushing and tingling in people with inflammatory acne or erythema.

So, yes, if you have inflammatory acne or erythema, you don’t want to use these two together. Scroll down to the fix to figure out how to make the most of them.

Everyone else, don’t worry. These reactions don’t happen straight away. They occur so slowly, you won’t even notice a difference. I’ve explained why in detail in this post.


  • Wait 30 minutes. Apply vitamin C first and, half an hour later, niacinamide. Or vice versa.
  • Don’t have that much time to waste in the morning? Then, use them at different times of the day or week.

Related: Can You Use Niacinamide And Vitamin C Together?