Before we dive into which ingredient is better for treating acne, it's important to note that they both can be irritating to the skin if used improperly. "Because they share many of the same properties and can both be irritating when applied too frequently or at too high of a concentration," said Dr. Lain. Dr. Gross added: "When you strip the skin's moisture barrier, you can actually make breakouts worse." To avoid this, make sure you're not overapplying or using multiple products with these ingredients, and be sure to introduce more calming and hydrating ingredients into your skin-care routine, as well.
To answer the question of which ingredient is better for treating acne, Dr. Lain explained it depends on the type of acne you're experiencing and how easy it is for you to get hold of the products (there are far more salicylic acid products readily available in the UK). "I find that salicylic acid is a bit better exfoliating product, therefore I recommend its use for patients with predominantly blackheads and whiteheads," he said. "[Benzoyl peroxide] is the preferred ingredient for those with predominantly pus bumps and pimples."
Conversely, Dr. Gross recommends salicylic acid over benzoyl peroxide to all of his patients, or alternatively, that they seek a different, maybe lesser-known acne-fighting ingredient altogether. "There are so many other great ingredients that work to tackle acne-causing bacteria that don't damage skin."
For salicylic acid and benzoyl peroxide product recommendations, keep reading.