Active Ingredients not to Mix in Your Cosmetics

Whether your beauty routine contains 20 products or a simple moisturizer, you benefit from knowing the compatibility of the active ingredients in your cosmetics. On the one hand to maximize the effectiveness of your treatments, and on the other hand to avoid irritating your skin.

Welcome to your 101 course in active ingredient mixology. On the menu, combinations of active ingredients to avoid, and our tips for circumventing the bothersome effects of these combinations.

Vitamin C

An ingredient with multiple virtues, vitamin C improves the uniformity of skin tone and minimizes the appearance of wrinkles. Thanks to its antioxidant properties, vitamin C also protects the skin from oxidative stress caused by the external environment which damages the structures of the skin.

Vitamin C and Retinol

Vitamin C and retinol are the ideal combination to reduce the appearance of wrinkles and hyperpigmentation. These two ingredients work hand in hand: retinol stimulates cell renewal and collagen production while vitamin C protects the integrity of the skin thanks to its antioxidant power.

But although it is a winning combination, it must be performed with caution. Indeed, these two ingredients can be irritating to the skin. To minimize the risk of irritation and maximize results, it is strongly recommended to alternate the time of application of these two products. For example, you could apply your vitamin C in the morning and your retinol in the evening.

Vitamin C and Niacinamide

Treatments containing pure vitamin C are often formulated at an acidic pH to maximize the effectiveness of this ingredient. It is this acidity that makes vitamin C-based treatments often irritating.

However, niacinamide is incompatible with an acidic pH. Indeed, when niacinamide comes into contact with an acidic environment, it can transform into niacin. This compound can create redness on your skin temporarily. And because niacinamide is transformed into another form, you lose its effectiveness.
To get around this incompatibility, you can alternate the application of your niacinamide and your vitamin C. For example, you could apply one product in the morning and the other The evening. You could also alternate the application of each product every other day.

In addition to this tip, products based on vitamin C derivatives are an excellent alternative to avoid irritating your skin. Cosmetics based on these derivatives can be formulated to the pH of the skin, making them gentler.

So, by choosing a product based on a vitamin C derivative, you can apply it at the same time as your niacinamide without having to worry about a compatibility problem.

Pure Face Oil is formulated with 5% stabilized vitamin C. Its minimalist formula allows you to combine your vitamin C with your other active ingredients like niacinamide.


Retinol is one of the most effective anti-aging ingredients. However, retinol can often lead to irritation and dryness of the skin. Retinol is also photosensitizing, meaning the skin becomes more sensitive to the sun's UV rays. It is therefore essential to apply sunscreen every morning and reapply it during the day.

Retinol and Chemical Exfoliants (AHA/BHA)

Chemical exfoliants such as glycolic acid, an AHA, can be irritating on their own. Their combination with retinol therefore has a high irritant potential. In addition, retinol performs indirect exfoliation of the skin by stimulating cell renewal.

Thus, the use of just one of these two ingredients is often sufficient to work on the texture of the skin. If you want to combine these two ingredients, alternate the application of your products with your AHA/BHA in the morning and your retinol in the evening.

Retinol and Benzoyl Peroxide

These two ingredients have interesting properties for those suffering from acne. However, given their chemical properties, retinol and benzoyl peroxide may cancel each other's activities. This is why it is best to apply your benzoyl peroxide in the morning and your retinol in the evening.


Niacinamide, also called vitamin B3, is an ingredient that mixes well with the majority of other active ingredients. This vitamin has anti-inflammatory and healing properties, in addition to regulating sebum production and reducing the appearance of hyperpigmentation (2,3,4).

Niacinamide and Chemical Exfoliants

As mentioned previously, combining niacinamide with a product with an acidic pH is not recommended. Therefore, applying niacinamide immediately after applying your AHA treatment could irritate your skin.

To get around this contraindication, you can alternate the time of application of your AHA treatment and your niacinamide.

Omy Laboratoires' personalized serum is formulated with 5% niacinamide to bring all the benefits of this ingredient to your skin. A 5% concentration of niacinamide has been shown clinically effective for various skin conditions.

Chemical Exfoliants

The family of chemical exfoliants includes AHAs and BHAs. These chemical exfoliants work in two ways. AHAs remove the buildup of dead cells on the skin's surface, while BHAs penetrate pores to help decongest them.

To make it easier to incorporate chemical exfoliants into your routine, you can use them just once or twice a week rather than daily. For example, you could use a triple exfoliation (chemical, enzymatic and physical) to effectively exfoliate your skin. A tri-exfoliating face mask can be applied once or twice a week to achieve visible results.

Natural Extracts

Generally speaking, there are no contraindications for mixing these extracts with other active ingredients.

Some extracts have similar properties to popular active ingredients like vitamin C and retinol, although they differ in effectiveness. For example, antioxidant-rich kakadu plum extract helps prevent the appearance of wrinkles while dragon fruit extract helps reduce the appearance of age spots.

You will find these extracts in Omy's personalized products as ingredients 5 and 7 respectively.

If you have any hesitation about mixing your active ingredients, do not hesitate to make an appointment with a skin expert to do a skin assessment over the phone.