Why do you get spots after using a new cosmetic product?

The causes of spots appearing on the face are multifactorial: hyperseborrhoea, accumulation of dead cells on the skin's surface, bacterial colonisation, stress, hormonal factors... In some cases, blemishes can also be caused by the use of new cosmetics, the mechanisms of action of which vary depending on the product. The main factors that can explain the appearance of spots on the face following the use of a new skincare product are as follows:

1. The cosmetic induces a purge.

   Also known as the “rebound effect”, skin purge is a natural process similar to an acne breakout that is characterised by the sudden appearance of spots in the days following the introduction of a new cosmetic product into one's skincare routine. The use of certain exfoliating actives indeed leads to an acceleration of cellular renewal, meaning that the cells from the deeper layers of the skin start to rise to the surface more quickly, eliminating all dead cells in the process and thus bringing out all imperfections at once. Without the purge, these would have emerged later, in a more gradual manner.

   Several factors can help determine if your new skincare product is causing your breakouts and if it is indeed a purge. Firstly, only certain actives are likely to trigger a purge. These are ingredients that promote skin exfoliation, such as organic hydroxy acids (AHA, BHA, PHA), retinoids or benzoyl peroxide. Furthermore, purging is a temporary phenomenon, typically lasting between one and two months. Finally, breakouts due to a purge tend to be located in areas already prone to acne. Even though the purge can be quite challenging to endure, it often heralds clearer skin, hence the importance of continuing to use the responsible cosmetic for a few months, provided it is indeed a purge.

2. The skincare product is comedogenic.

   If you notice that you have more spots than usual after using a new product, it is possible that this product is comedogenic for your skin. This term refers to the ability of an ingredient or a cosmetic to clog the pores of the skin, thereby promoting the appearance of comedones. These are often products with a rich texture that, by forming an occlusive film on the skin's surface, hinder the natural evacuation of sebum.

   It is important to note that the concept of comedogenicity varies from one skin type to another. Indeed, if oily and acne-prone skin types are particularly affected by comedogenicity, dry skin types are almost never confronted with this issue. To determine if your spots are due to the comedogenic nature of your new cosmetic product, we advise you to check its INCI list. If a comedogenic ingredient is present in the top three positions, it is likely that the product is indeed the cause.

3. The skin does not tolerate the product.

   Occasionally, the skin may be sensitive to an active ingredient and not tolerate it. The use of cosmetics containing such ingredients can then lead to a negative skin reaction that may resemble a breakout of spots. Imperfections caused by an allergy often slightly differ from those caused by a purge or a comedogenic product, typically resembling small red spots grouped in patches.

   When the epidermis does not tolerate a substance, it initiates a inflammatory response characterised by the activation of T lymphocytes and the release of cytokines and other inflammation mediators. This response leads to vasodilation and an increase in the permeability of blood vessels, allowing fluids, plasma proteins, and immune cells to penetrate the skin tissues. Redness, swelling, and spots can then be observed. After the offending cosmetic is removed, the spots disappear spontaneously.

If you notice spots after using a new cosmetic product, do not immediately conclude that it is the culprit. As mentioned earlier, there are multiple causes for spots.

• FULTON J. E. Comedogenicity and Irritancy of Commonly Used Ingredients in Skincare Products.Journal of the Society of Cosmetic Chemists (1989).

• MISRA S. & al. Acne: a prevalent skin problem. World Journal of Pharmaceutical Research (2021).

• GAJBHIYE S. & al. Review article: skincare through the process of exfoliation. International Journal of Current Science (2022).