11 Skincare Ingredient Combinations You Should Never Mix + Some You Should

Skincare used to be simple. Cleansing with Pears Transparent Soap was usually followed by a moisturizer, like Nivea. Once empty, ladies would just buy the same products, and that was all the fuss.

Today, things are a bit different. Beauty routine became slightly more complicated, and we have plenty of other products to choose from. This is great because each of them offers distinct benefits. On the other hand, there's more room for mistakes as mixing some of them could be counterproductive, causing the destabilizing of active ingredients or skin irritation.

So, before stocking up your bathroom or vanity with a myriad of different skincare products, read on to find out which ones you shouldn't mix and which ones work harmoniously.

#1: Retinol and Benzoyl Peroxide

Both retinol (or any other retinoid) and benzoyl peroxide are excellent acne treatments. And if you're dealing with acne, you're likely using them both. However, these shouldn't be used together as a part of the same skincare routine. When layered together, these actives might irritate your skin, leading to dryness, flakiness, and other side effects. Additionally, they'll make each other less effective as benzoyl peroxide is known to degrade many forms of topical vitamin A, except adapalene.

Therefore, dermatologists recommend using retinoids in the evening before going to bed and delegating benzoyl peroxide to your morning skincare routine.

#2: Retinol and AHAs

Topical vitamin A products and AHAs (alpha hydroxy acids) are both active anti-aging ingredients that do similar things. While retinol doesn't exfoliate the skin as AHAs do, it has similar effects, speeding up cell turnover and making way for new, regenerated skin cells. Using these two ingredients together will lead to dryness and irritation, which can then worsen your acne, hyperpigmentation, and other skin conditions you're trying to correct.

But this doesn't mean you should completely exclude one or the other from your skincare routine. Just don't use them at the same time. So, for example, you can use your retinol or retinoid on Mondays and Thursdays, and your AHAs (glycolic, lactic, and mandelic acid), on other days of the week.

#3: Retinol and Vitamin C

Retinol and retinoids are powerful ingredients that can do a lot for your skin, stimulate collagen production, reduce fine lines and wrinkles, mitigate acne, and fade hyperpigmentation. Vitamin C also promises to reduce signs of aging, fade dark spots, and brighten your skin tone.

Used separately, these ingredients can indeed do wonders for your skin. However, if paired together, your skin will get irritated and uncomfortable instead of glowing.

So, use your favorite retinol and vitamin C products in separate skincare routines. Introduce vitamin C in your morning routine, and leave retinol for your p.m. skincare regimen.

#4: Retinol and Salicylic Acid

Salicylic acid is a BHA, beta hydroxy acid, that exfoliates the skin and helps control sebum production and reduce acne. One common side effect of using salicylic acid is dryness. Since both retinol and salicylic acid can cause similar side effects, like irritation, dry skin, and flakiness, your best bet is to avoid using them together.

Therefore, the same rule applies – save your retinol for your p.m. routine, and use salicylic acid in the morning.

#5: Benzoyl Peroxide and Vitamin C

Benzoyl peroxide causes vitamin C to oxidize, degrading it and making it lose its potency. Therefore, if you want to banish acne but keep your complexion even and bright, use these two as parts of different skincare routines.

In this case, it would be best to keep benzoyl peroxide-based products for your evening skincare routine and vitamin C for the morning.

#6: Vitamin C and AHAs or BHAs

Vitamin C is an acid, ascorbic acid, and highly unstable one. Mixing it with other acids, such as glycolic or lactic acid, will render it ineffective. The only thing you can get from this combination is more irritation and worsening of your skin concerns.

So, stick to your morning vitamin C routine, and leave other acids to do their magic in the evening.

#7: Vitamin C and Soap-Based Cleansers

For Vitamin C to work, it needs to be formulated with a low PH. Soap-based cleansers, on the other hand, usually have a higher PH. If you first wash your face with a soap-based cleanser, you'll raise your skin's PH level, and it won't be able to absorb your vitamin C serum.

Keeping in mind that vitamin C products are not the cheapest, you'll only waste your money if you stick to this routine. Moreover, you'll miss out on all the benefits a well-formulated vitamin C antioxidant has to offer.

Therefore, avoid soap-based cleansers before your vitamin C serum. But rather, go for gentle cleansers with hydrating and soothing ingredients, such as glycerin or hyaluronic acid.

#8: Hydroquinone and Benzoyl Peroxide

Try to avoid using hydrogen peroxide, and other products containing hydroquinone, with benzoyl peroxide. These two ingredients are both very potent; benzoyl peroxide is effective in treating acne, while hydroquinone acts as a skin-lightening agent.

These two combined are a recipe for disaster, leading to skin irritation and temporary darkening and discoloration of the skin. The latter is nothing to worry about, though, as the effect will quickly dissipate with the first or second face wash.

#9: AHAs and Hydroquinone

Hydroquinone can be pretty irritating on its own. Therefore, adding other irritating ingredients, such as AHAs or retinoids, to your hydroquinone routine isn't recommended. Thus, separate them into your morning and evening skincare routine.

Hydroquinone is best used at night. Therefore, you can use your AHA in the morning, but then you need to maximize your sun protection.

#10: Water-Based and Oil-Based Skincare

Simply put, your water-based moisturizer won't work over your oil-based serum – or it will, but to a much lesser extent and potency. Oil-based formulas will prevent water-based ones from penetrating your skin.

So, while there won't be any adverse effects, like irritation, from mixing these, you might hinder some of your products from doing their job if you don't pay attention to how you layer them. Therefore you can combine oil-based with water-based skincare products as long as you layer them correctly and apply the latter first. It's always a good idea to finish your skincare routine with oil-based formulas to seal all the hydration and actives in.

#11: Two Products With the Same Ingredients

There's no reason you should use two products with the same actives as a part of a single skincare routine. So if you start your routine using an AHA-based cleanser and finish it off with a moisturizer with mandelic acid in it (also an AHA), your doubling up on the potential risk of irritation and dryness.

Another example would be combining several different forms of topical vitamin A. This won't yield better results. It can only cause the disruption of your skin's natural barrier, resulting in more irritation and worse outcomes.

So, skip stacking products with the same actives in them, as it can only lead to irritation and related skin issues.

Takeaway...

As skincare fanatics ourselves, we understand your need to try different products and make a proper little personal lab out of your skincare collection. But please be careful while experimenting, especially with strong actives, such as retinoids, chemical peels, potent acne treatments, and others.

In the end, you'll be risking some adverse side effects, like redness, irritation, burning, and others. Or, in the best-case scenario, your products might not work as they should.

So, pay attention if you like using some of the pairings that we listed above and, avoid using them as part of the same skincare routine. You can also always ask your dermatologist for advice on building and layering your skincare products for the best possible results.

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