The Ultimate Guide: Skincare Ingredients You Should NEVER Mix

When it comes to skincare, less is often more. So, today we’ll be doing a little skincare chemistry lesson. While it may seem like it’s helpful to add all the best ingredients to your skin at once, it can actually do more harm than good. Certain ingredients mixed together can be irritating, throw off your skin’s pH, and cause breakouts. It can also be wasteful; some ingredients such as Vitamin C can be deactivated when mixed with other products, so you’re basically throwing your money down the drain if you don’t know what you’re doing. Here are a few skincare ingredients that you should never mix together.

Benzoyl Peroxide & Retinol

Both benzoyl peroxide and retinol are effective acne-fighting ingredients, but when layered together they deactivate each other, causing both to be ineffective. At worse, used together they can irritate the skin and make it more red and irritated. You can use both ingredients, but just not at the same time. It’s best to use benzoyl peroxide in the morning and retinol at night.


Vitamin C & AHAS/BHAS

Vitamin C is a powerful ingredient that is known to brighten the skin. What many don’t know is that it’s also an acid!  So combining it with AHA’s (glycolic & lactic acid) and BHA’s salicylic acid) is not only irritating for the skin, but it becomes destabilized and ineffective. If you would like to use both, use Vitamin C in the morning (before sunscreen) and AHA’s and BHA’s at bedtime.

Vitamin C & Benzoyl Peroxide

To continue on the subject of Vitamin C, as a general rule it should be used alone, not mixed with other aggressive, acidic ingredients. Benzoyl Peroxide is a strong ingredient which dries and exfoliates the skin, so using it along with Vitamin C makes it highly irritating and unstable. It’s best to alternate these two ingredients in the evening.

AHA’S (Glycolic & Lactic Acid) & BHA’s (Salicylic Acid)

When it comes to acids, less is DEFINITELY more. Both AHA’s and BHA’s are exfoliating ingredients and only one type is needed to do the job. While having these two acids mixed in a controlled professional environment with an aesthetician or with a dermatologist may be ok, do not mix both on your own. It can be highly irritating and unnecessary! However, we do recommend trying each type of acid separately to see which one works best for you. Each person’s skin reacts differently to each of these acids, so one may work better for your skin type and it’s worth exploring. For example, glycolic is the strongest and lactic acid is the more gentle of the two AHA’s, so if you have sensitive skin, you may prefer lactic acid. Additionally, salicylic acid (BHA) is more commonly used and works more broadly than AHA’s, so you may find your skin reacts better to BHA’s. Either way, you’ll have to try each to find out, just don’t mix them together.

Sunscreen + Anything

In order to be most effective, sunscreen is meant to be put on first which creates a barrier on your skin. In other words, nothing else can penetrate your skin once you apply sunscreen. So anything else you add (besides makeup and eye cream) is pointless and will not absorb into your skin. Instead just apply sunscreen, then a mineral based makeup such as BareMinerals to maximize sun protection.


Retinol & AHAS/BHAS & Vitamin C

Simply put, do not mix any sort of exfoliant with another exfoliant. Retinol, BHA’s, AHA’s, and Vitamin C are all acidic and remove the outer layer of the skin. Too many of these types of exfoliants can strip the skin, throw off its pH, and cause irritation. Just stick to one, and alternate them in the morning or night, but never layer them.

Retin-A & Peels or Waxing

Retin-A is a deeply exfoliating ingredient and causes the skin to peel quite a bit, so mixing it with another peel or waxing can actually rip your skin off and cause scarring. If you are using Retin-A, avoid chemical peels or waxing altogether. If you want to do a wax or peel be sure to discontinue use of Retin-A at least 3 to 4 days ahead of time.

Vitamin B (Niacinamide) & AHA’s

Vitamin B is an excellent repairing ingredient for the skin. It works to refine texture, fade hyperpigmentation, and moisturize. However, it requires an environment with a neutral pH to be effective. Added with AHA’s it’s rendered useless due to AHA’s low pH level. Don’t add it to acidic environments or it’s essentially wasted.

Oil-Based & Water-Based

We all know water doesn’t mix with oil! So, if you apply an oil-based product to your skin, then try to add a water-based product it will be unable to penetrate the epidermal layer, rending it useless. To maximize effectiveness, use water-based and oil-based products separately.

Benzoyl Peroxide + Hydroquinone

Both of these ingredients have lightening effects on the skin and they’re both potentially irritating, so adding them together can create a mess for your complexion. Not only will they cause irritation together but they will make your skin extremely sensitive to the sun,  potentially causing more sun damage, spots, and acne, so mixing these together is a huge NOPE. Thank u, next.

What To Do Instead

Now that you know what NOT to mix together, the fix for utilizing your ingredients properly is simple; alternate your conflicting products.  Use one in the morning and one in the evening or alternate every other day or every few days. As a general rule, exfoliators should be applied in the evening, so we recommend avoiding exfoliaters such as AHA’s, BHA’s, and retinol during the day, as they create sun sensitivity. Instead, use an anti-aging moisturizer with sunscreen during the day, such as Peter Thomas Roth Max Sheer All Day Moisture Defense Lotion SPF 30, and alternate your Vitamin C and other exfoliaters in the evenings.

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The Ultimate Guide: Skincare Ingredients You Should Never Mix





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