Benzoyl peroxide is a staple in treating mild acne. It is effective in getting rid of bacteria and reducing bacterial resistance. It is also anti-inflammatory. Benzoyl peroxide can be found as an over-the-counter wash and in topicals at low concentrations. It can also be found in prescription medications such as Twyneo, which contains benzoyl peroxide and a retinoid. Concentrations of benzoyl peroxide between 2.5% and 10% were approved for safe usage.
Benzoyl peroxide was approved as a safe medication for treating small pimples. However, an independent lab called Valisure filed a claim that when exposed to high heat, benzoyl peroxide breaks down into benzene–a carcinogenic compound. Valisure tested benzene levels in benzoyl peroxide at 98.6, 122, and 158 degrees Celsius for 18 days. The lab saw unacceptable benzene levels in a few products containing 2.5% benzoyl peroxide at 50 degrees Celsius.
The report from Valisure is incomplete, as it is missing critical information such as product purchase date and the ideal storage temperature for the products. For people who choose to avoid benzoyl peroxide, there are alternative treatments.
For acne treatment, the standard recommendation is to use topical retinoids like over-the-counter adapalene 0.1% or prescription tretinoin 0.025%, starting 2-3 times a week to minimize irritation. Sunscreen use is crucial due to increased photosensitivity from retinoids.
For those who cannot tolerate retinoids, alternatives include salicylic acid or azelaic acid, which can also be used alongside retinoids if tolerated.
Topical and oral antibiotics should be combined with benzoyl peroxide to prevent resistance. For women with moderate to severe acne, oral contraceptives or spironolactone may be effective. Isotretinoin is recommended for severe cystic acne or acne causing scarring that doesn’t respond to other treatments.
Regarding benzoyl peroxide products, refrigerating the products, renewing them every 3 to 6 months, and avoiding heated storage will slow the decomposition of benzene.