Benzoyl peroxide and salicylic acid are topical preparations used to treat various skin conditions, including acne. While both are used for similar reasons, the way they work is different. When treating acne, choose one product containing either benzoyl peroxide, or salicylic acid. Mixing the use multiple products with both active ingredients increases the risk of irritation.
The drug known as Benzoyl peroxide works by killing the bacteria that cause acne. It does this by working both as an antiseptic, killing the bacteria outright, and as an oxygenator, carrying oxygen into the pores. The bacteria that causes acne is anaerobic, meaning that it requires an oxygen-free environment to live. Benzoyl peroxide has no residual effect, meaning continued use is necessary to keep skin clear.
By contrast, salicylic acid softens the skin's keratin. This loosens the skin's cells that block the pores. Salicylic acid also slows down the process of exfoliation within the pore, reducing future blockages, and breaking down existing blackheads and whiteheads.
Both benzoyl peroxide and salicylic acid are safe and generally well-tolerated. Both chemicals, however, can lead to skin irritation in certain individuals. To reduce the risk of irritation, begin applying the medicine every three days, gradually increasing the frequency if there is no sign of irritation. If redness, stinging, or irritation develop, discontinue use until symptoms disappear, and then try a product with a different active ingredient.
Possible side effects of benzoyl peroxide use include blistering, itching, burning, crusting and swelling of the treated area, as well as a rash, peeling, dry skin, and warmth in the affected area. Ingesting benzoyl peroxide may lead to nausea, vomiting, and abdominal pain.
Aside from possible skin irritation, the side effects of using salicylic acid include warm, red skin and flushing. If ingested, salicylic acid can cause confusion, nausea, diarrhea, vomiting, headache, dizziness, drowsiness, rapid breathing, and ringing or buzzing in the ears.
Both benzoyl peroxide and salicylic acid are affordable and widely available. Benzoyl peroxide is only used as an acne treatment. It has bleaching properties and may bleach clothing or bedsheets that it comes into contact with before it dries. On the other hand, salicylic acid is commonly used as a treatment for warts, dermatitis, psoriasis, and other skin conditions, in addition to treating acne. Both benzoyl peroxide and salicylic acid increase the skin's sensitivity, and users should protect their skin with sunscreen while using the products.