Did you know that certain combinations of active skincare ingredients can do more damage than good to your skin?

For example, someone with blemish-prone skin might consider using a BHA liquid exfoliant to unclog pores and reduce inflammation and a Niacinamide serum to help regulate the production sebum, reducing the likelihood of clogged pores and to improve skin texture. Unfortunately, using these two ingredients together can lead to skin irritation and redness.

Anothor example is someone wanting a more youthful appearance using Retinol to increase cell turnover and reduce the appearance of fine lines and wrinkles and Vitamin C to help brighten dark spots from sun damage. Using Retinol and Vitamin C together can lead to irritation and even reduce the effectiveness of one another.

Although it’s not suggested to mix Retinol with Vitamin C at home, Lancôme have recently launched their NEW Rénergie C.R.x. Triple Serum. This serum safely and effectively combines three active ingredients into one triple dose, which includes Pure Retinol and Pure Vitamin C.

I have created a simple yet very useful diagram that helps to quickly identify which active ingredients should and should not be used together.

Although some of the active ingredients shouldn’t be used together, they can be used on separate days or at different times of the day, e.g., using a Retinol serum as part of your evening skincare routine and a Vitamin C serum as part of your morning skincare routine.

Sources

Lois. Navigating Skincare Ingredients: What to Mix and What to Avoid. Published 17 May 2024. https://www.revolutionbeauty.com/uk/en/revsays/what-skincare-ingredients-to-not-mix.html

Boots Beauty Team. Skincare ingredients you should & shouldn’t mix. Published 01 May 2020. https://www.boots.com/skincare-beauty-advice/skincare-advice/skincare-basics/skincare-ingredients-you-should-and-shouldnt-mix

SkinCeuticals. The Dos & Don’ts of Mixing Skincare Ingredients. Lasted Accessed 01 May 2025. https://www.skinceuticals.co.uk/en_GB/the-dos-and-donts-of-combining-skincare-ingredients.html

askINKEY Skincare Advisor. What products should I not layer together? Published 20 September 2021. https://uk.theinkeylist.com/blogs/news/what-products-should-i-not-layer-together

Ronelle Richards. The dos and don’ts of mixing skincare ingredients. Last Updated 29 November 2024. https://www.skin.software/journal/skincare-ingredients-that-dont-mix

Mercedes Santaella-Lam. Niacinamide and Vitamin C. Last Updated 27 March 2024. https://www.paulaschoice.com/expert-advice/skincare-advice/skin-care-myths/can-niacinamide-and-vitamin-c-be-used-together.html