The answer, as with most things in life, is: it depends. In this guide, I'll discuss which ingredients should and shouldn't be combined, and why. I'll also provide a list of ingredients that work well together and can be safely mixed. So if you're looking to get the most out of your skincare products, keep reading!

Retinol

One of the most popular skincare ingredients, retinol is derived from vitamin A and is used to treat a variety of skin concerns, including wrinkles, fine lines, and hyperpigmentation. Retinol is available in over-the-counter products as well as prescription-strength formulations.

While retinol is generally considered safe, it can be irritating to the skin. Therefore, it's important to use a low-strength retinol product if you're new to this ingredient.

Smiling young woman applying moisturiser to her face

Do mix: If you're using a low-strength retinol product, you can safely mix it with other skincare ingredients. Just be sure to start slowly and increase the frequency of use as your skin adjusts.

Retinol can be mixed with ingredients such as hyaluronic acid, SPF, and niacinamide.

Don't mix: Retinol should not be mixed with exfoliating ingredients such as AHAs and BHAs. Additionally, retinol should not be used with vitamin C or Benzoyl peroxide products as this can cause irritation. If you do want to use a product containing vitamin C, be sure to apply it at a different time of day than your retinol product.

AHAs and BHAs

AHAs (alpha hydroxy acids) and BHAs (beta hydroxy acids) are exfoliating ingredients that are used to improve the appearance of the skin. AHAs work by dissolving the bonds that hold dead skin cells together, while BHAs penetrate deeper into the pores to remove sebum and other impurities.

Read more: AHA Vs. BHA

Both AHAs and BHAs can be irritating to the skin, so it's important to start slowly when using these ingredients. Additionally, since these ingredients can make the skin more sensitive to sunlight, it's important to use sunscreen with an SPF of 30 or higher when using products containing AHAs or BHAs.

Liquid oil serum drop in pipette. AHA, BHA acid.

Do mix: You can safely mix AHAs and BHAs with other skincare ingredients, although it's important to start slowly and increase the frequency of use as your skin adjusts.

AHAs and BHAs can be mixed with moisturizing ingredients such as hyaluronic acid, ceramides, and glycerin. It can also be mixed with SPF for added sun protection.

Don't mix: AHAs and BHAs should not be used with retinol products as this can cause irritation. Additionally, these ingredients should not be mixed with vitamin C products as this can also irritate your skin.

Benzoyl peroxide

Benzoyl peroxide is a popular skincare ingredient that is used to treat acne. Benzoyl peroxide works by killing the bacteria that cause acne, as well as by drying out the pimple.

While benzoyl peroxide is generally considered safe, it can be irritating to the skin. Therefore, it's important to start slowly when using this ingredient. Additionally, benzoyl peroxide can make the skin more sensitive to sunlight, so it's important to use sunscreen with an SPF of 30 or higher when using products containing this ingredient.

Do mix: Benzoyl peroxide can be mixed with ingredients such as hyaluronic acid, niacinamide, and glycerin. It can also be mixed with SPF for added sun protection.

Don't mix: As previously mentioned, benzoyl peroxide should not be used with retinol products as this can cause irritation. Additionally, benzoyl peroxide should not be mixed with other acne treatments such as tretinoin, as they can deactivate each other.

Vitamin C

Vitamin C is a skincare ingredient that is known for its brightening and antioxidant properties. Vitamin C can be derived from citrus fruits or synthetically produced. It helps to brighten the skin and protect it from environmental stressors.

Do mix: Vitamin C can be mixed with ingredients such as vitamin E, ferulic acid, and other antioxidants.

Don't mix: Vitamin C should not be used with retinol products as this can cause irritation. Additionally, vitamin C should not be mixed with niacinamide since the effectiveness of vitamin C will be decreased.

As mentioned above vitamin C should not be mixed with AHAs or BHAs, or benzoyl peroxide products. If you want to use a product containing vitamin C, be sure to apply it early in the morning and use the other products at night.

Niacinamide

Niacinamide is a skincare ingredient otherwise known as vitamin B3. It is known for its ability to brighten the skin and improve the appearance of enlarged pores. Niacinamide can also help to reduce inflammation and redness.

Do mix: Niacinamide can be mixed with almost any other skincare ingredient, except vitamin C products.

Don't mix: As mentioned above, niacinamide should not be used with vitamin C products as this can decrease the effectiveness of vitamin C.

Sunscreen (SPF)

Sunscreen is an important skincare ingredient that should be used daily, regardless of whether you're using other skincare products. Sunscreen helps to protect the skin from the harmful effects of the sun's ultraviolet rays.

Close-up of woman's hands with sunscreen

Conclusion

When it comes to skincare ingredients, more isn't always better. In fact, combining certain ingredients can cause irritation, redness, and breakouts. So if you're unsure about whether or not two ingredients can be mixed, it's always best to err on the side of caution and use them at different times or on alternate days. And remember: less is often more when it comes to skincare!

If you're looking for customized skincare advice, book an appointment with me today. I'll help you create a skincare routine that is tailored to your specific skin type and needs.

Take care of your skin – it's the only one you've got!