Last Updated on May 19, 2025 by Giorgia Guazzarotti

skincare ingredients to never use together

What are the skincare ingredientsyou should never mix 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! And the worst part? You don’t even get a warning label. You just wake up one morning with a red, irritated face wondering what the hell went wrong. 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). Sounds amazing, right? Except when your face feels like it’s been sandpapered.

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. But pile them all on at once, and it’s like inviting three DJs to play at the same party. Chaos.

When used together at the same time, 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.

THE FIX

  • 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.
  • Pro tip: if you’re new to either, don’t start both in the same week. Your skin will file a complaint.

Best Retinol Picks:

  • The Ordinary Granactive Retinoid 2% Emulsion ($12.10): This simple formula contains both retinol and granactive retinoid (a new and gentler form of retinoid). Available at Beauty BayBootsCult BeautySephoraThe Ordinary, and Ulta
  • Paula’s Choice Resist 1% Retinol Booster ($52.00): A high dose retinol serum infused with antioxidants to help you fight premature aging. You can use it on its own or mix a couple of drops with your moisturiser. Available at Cult BeautyDermstore, and Paula’s Choice, and SpaceNK
  • Paula’s Choice Super Antioxidant Concentrate Serum With Retinol ($39.00): This serum has a tiny dose of retinol that’s suitable for beginners. Plus, it’s infused with any antioxidants to fight premature aging. Available at Dermstore and Paula’s Choice

Best AHAs/BHA Picks:

  • Drunk Elephant T.L.C. Framboos Glycolic Night Serum ($90.00): This exfoliant has both salicylic acid to unclog pores and glycolic acid to fade away the dark spots pimples sometimes leave behind. Available at Cult Beauty and SpaceNK.
  • Paula’s Choice Skin Perfecting 2% BHA Liquid ($29.00): The cult exfoliant from the brand, it unlclogs pores and treats blackheads and acne. The texture’s a little sticky, though. Available at Cult BeautyPaula’s ChoiceSephora, and SpaceNK.
  • The Ordinary Glycolic Acid 7% Toning Solution (£6.80): If you’re on a budget, this gentle, no-frills Glycolic Acid exfoliant will get the job done. Available at Beauty Bay and Cult Beauty

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. Basically, they’re both trying to evict your pimples, but end up setting fire to the whole building. Do you really wanna take the risk?

THE FIX

  • 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. Sulfur smells a bit like rotten eggs, but it gets the job done without torching your face. Priorities.

Best Benzoyl Peroxide Picks:

  • Proactiv Repairing Treatment with Benzoyl Peroxide ($35.00): It has a low, 2.5% concentration of Benzoyl Peroxide in a silicone base. Enough to get the job done. Available at Proactiv and Ulta
  • Bubble Fade Away 5% Benzol Peroxide Acne Spot Treatment ($12.00): This spot treatment is loaded with soothing ingredients to fight acne without upsetting your skin too much. Available at Ulta
  • Differin 10% Benzoyl Peroxide Spot Treatment ($11.49): A high-strength Benzoyl Peroxide treatment to get rid of stubborn acne. Use it carefully! Available at Ulta

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


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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. They’re like the Beyoncé and Rihanna of skincare. Total icons, but not exactly known for sharing the stage.

You guessed it,, 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 like trying to throw a pool party and a formal dinner at the same time. No one’s happy.

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. Think of it like your Wi-Fi at a crowded airport. Functional, but not exactly fast.

THE FIX

  • Use these ingredients at different times of the day or week. Vitamin C in the morning = antioxidant armor. Retinol at night = skin regeneration party. Boom.
  • 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.

Best Vitamin C Picks:

  • MaeLove Glow Booster ($27.95): The cheapest Vitamin C serum in this list, it does everything the others do, but it contains a citrus extract that may be irritating for sensitive skin. Available at Maelove.
  • Paula’s Choice C15 Booster ($46.75): It’s enriched with Hyaluronic Acid and glycerin to deeply hydrate skin. Available at Cult BeautyDermstorePaula’s ChoiceSephora, and SpaceNK.
  • Skinceuticals CE Ferulic ($169.00): The original Vitamin C serum, it costs an arm and a leg, but it works wonders and delivers what it promises. Available at Dermstore and Skinceuticals.

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.

THE FIX

FYI, this is only for people who experience this flushing. If that’s not you, there’s nothing to fix, so skip this.

  • Wait 30 minutes. Apply vitamin C first and, half an hour later, niacinamide. Or vice versa. Yes, it’s a hassle. But so is flaky, red skin. Pick your battles.
  • Don’t have that much time to waste in the morning? Then, use them at different times of the day or week.

Best Niacinamide Picks:

  • Paula’s Choice Resist 10% Niacinamide Booster ($42.00): It shrinks your pores, hydrates your skin, and brightens the complexion. Plus, it’s full of antioxidants (including Vitamin C) to help you keep those pesky premature wrinkles at bay, too. Available at Cult BeautyDermstorePaula’s ChoiceSephora, and SpaceNK
  • The Inkey List Niacinamide ($6.99): On top of hydrating niacinamide, it also has hyaluronic acid to add moisture back into the skin and Squalane to strengthen its protective barrier. Plus, it brightens skin and helps prevent wrinkles. Available at BootsCult BeautyThe Inkey List
  • The Ordinary Niacinamide 10% + Zinc 1% (£5.00): Suitable only for oily skin, it reduces excess oil, helps treat acne, and reduces redness and inflammation. Available at Beauty BayBootsCult BeautySephoraSpaceNKThe Ordinary, and Ulta

Related: Can You Use Niacinamide And Vitamin C Together?

The Bottom Line

Skincare isn’t a free-for-all, it’s more like speed dating for ingredients. Some just aren’t meant to be in the same room. But that doesn’t mean you have to give up your faves. You just need to know how to introduce them properly. Space them out. Layer with care. Use the chill versions. And for the love of glowing skin, stop assuming more = better. Your skin isn’t a science experiment. It’s just trying to keep up. Treat it like a VIP guest, not a chemistry lab, and it’ll pay you back in glow.