This is probably the most common OTC acne treatment. Benzoyl peroxide is an oxidizing agent that is applied to the skin and absorbed by the pores. Benzoyl peroxide creates free radicals inside the pores which kills the bacteria that cause acne. Benzoyl peroxide also promotes the drying of sebum and encourages the shedding of skin cells to avoid pore blockage. It is best to use the benzoyl peroxide 2.5% gel against the 5% benzoyl peroxide gel because it is less irritating and has the same effect as with the 5% gel. Benzoyl Peroxide does not induce bacterial resistance so it is also good for long term use. Since benzoyl peroxide is an oxidizing agent, this acne medication can bleach your hair and your clothes.
Precautions and Side Effects:
Do not use benzoyl peroxide without consulting your doctor if you are pregnant or could become pregnant during acne treatment. This acne medication is not intended to be used on children.
Benzoyl Peroxide causes a stinging sensation in the skin, light peeling of the skin, and redness of the skin. People with very sensitive skin may experience flaking and scabbing.
The 2.5% benzoyl peroxide formulation was more effective than its vehicle and equivalent to the 5% and 10% concentrations in reducing the number of inflammatory lesions (papules and pustules). Desquamation, erythema, and symptoms of burning with the 2.5% gel were less frequent than with the 10% preparation but equivalent to the 5% gel. The 2.5% formulation also significantly reduced Propionibacterium acnes and the percentage of free fatty acids in the surface lipids after 2 weeks of topical application.
(Source: Comparing 2.5%, 5%, and 10% benzoyl peroxide on inflammatory acne vulgaris.Mills OH Jr, Kligman AM, Pochi P, Comite H.)
A water-based 5% benzoyl peroxide gel was compared with topical 1% clindamycin phosphate solution in the treatment of acne vulgaris using a randomized, investigator blind study design. Lesion counts were significantly reduced in both treatment groups over the 12-week study period; however, the reduction of total lesions produced by benzoyl peroxide gel was significantly greater than that produced by clindamycin phosphate (P< 0.05). Clindamycin phosphate had a milder effect on the skin surface in terms of peeling and drying than the benzoyl peroxide gel.
(Source: L.J. SWINYER, M.D. BAKER, THALIA A. SWINYER, O.H. MILLS Jr (1988) A comparative study of benzoyl peroxide and clindamycin phosphate for treating acne vulgaris British Journal of Dermatology 119 (5), 615–622.)
Benzoyl Peroxide is available in gel or cream form at 2.5%, 5% and 10% concentration. The cream or gel is topically applied on the skin.