Benzoyl peroxide, an effective solution for eliminating spots.

Numerous studies have demonstrated that benzoyl peroxide is capable of effectively combating acne, and this is based on a combination of several distinct mechanisms of action. Indeed, it possesses antibacterial, sebostatic, keratolytic and anti-inflammatory properties.

• Benzoyl peroxide possesses antibacterial properties.

  When benzoyl peroxide is applied to the skin, the cysteine present in the epidermis dissociates the peroxide bond of the compound. This produces, on one hand, a benzoyl radical, which is rapidly eliminated by the body, and on the other hand, radicals, including reactive oxygen species, such as superoxide ions (O2•−) and hydroxyl radicals (HO•). These radicals interact with bacterial proteins by oxidising them, thereby disrupting their survival and functions.

  According to a study published in the Journal of the National Center for Biotechnology Information, daily application of 10% benzoyl peroxide for two weeks resulted in a 98% reduction in the amount of Cutibacterium acnes in hair follicles. These results are comparable to those achieved with antibiotic therapy. However, these findings should be interpreted with caution, as the number of participants in this test was not disclosed.

• Benzoyl peroxide protects sebum from oxidation.

  This same study highlighted the role of benzoyl peroxide in sebum protection. It indeed allowed a 50% reduction in free fatty acids resulting from the degradation of sebum by the bacteria Cutibacterium acnes, which is responsible for inflammatory reactions. Indeed, saturated fatty acids, such as palmitic acid (C16:0), can induce the production of pro-inflammatory cytokines in sebocytes and keratinocytes, thereby exacerbating acne.

• Benzoyl peroxide possesses keratolytic properties.

  Simultaneously, the specific molecules obtained by dissociation of benzoyl peroxide can decompose into carbon dioxide. Indeed, benzoyl peroxide, upon contact with the skin, decomposes to produce two radicals, the benzoyl radical and reactive oxygen species. The unstable benzoyl radical splits into a phenyl radical (C6H5) and carbon dioxide (CO2). This promotes cell renewal by stimulating the detachment of dead cells from the skin surface. Indeed, CO2 mildly acidifies the environment and enhances the metabolic activity of cells, which contributes to the natural desquamation of dead cells and the overall improvement of skin health.

• Benzoyl peroxide possesses an indirect anti-inflammatory action.

  Finally, by reducing the bacterial load, benzoyl peroxide lessens local inflammation. Indeed, with fewer bacteria present to trigger an immune response, skin inflammations subside, and redness and spots decrease.

However, although the free radicals produced by the benzoyl peroxide are essential in the treatment of acne, their excessive presence can lead to phototoxicity. Therefore, it is important to use this product in the evening and apply sun protection the following day.