What is benzoyl peroxide?

Benzoyl peroxide is a commonly used topical treatment for mild acne. It is safe for adults and children and can be used in pregnancy.

Benzoyl peroxide has the following properties:

• Antiseptic: it reduces the number of skin surface bacteria (but it does not cause bacterial resistance and in fact can reduce bacterial resistance if this has arisen from antibiotic therapy). It also reduces the number of yeasts on the skin surface.
• Oxidizing agent: this makes it keratolytic and comedolytic (it reduces the number of comedones).
• Anti-inflammatory action.

Benzoyl peroxide is available as cream, gel, lotion and washes at concentrations of 2.5 %, 5 % and 10 %. It may be combined with other topical or oral therapy. It is especially valuable in combination with topical or oral antibiotics as it may reduce the growth of antibiotic-resistant bacteria.

In New Zealand, products containing benzoyl peroxide are available without a prescription. They include:

• Benoxyl™ 5%, 10% Lotion
• Benzac™ AC2.5%, 5%, 10% Gel; Wash 5%
• Brevoxyl™ 4% Cream
• Oxy™ 5 5% lotion, Oxy™ 10 10% Lotion
• PanOxyl™ 2.5%, 5%, 10% Gel, PanOxyl™ AQ 2.5%, 5%, 10% Gel

Benzoyl peroxide is also available on prescription in combination with other active agents.

• Epiduo® gel: benzoyl peroxide with adapalene, a topical retinoid
• Duac® Once Daily gel: benzoyl peroxide with clindamycin, a topical antibiotic

How to use benzoyl peroxide products

• Make sure the skin is clean and dry before applying
• Apply a thin smear to areas of skin affected by acne, initially every second night, then build up to once or twice daily as tolerated
• It can be used on the face as well as the trunk
• Be patient: acne responds very slowly to treatment. It may take several months to notice an improvement

Problems with benzoyl peroxide products

• Dryness of the treated area can be expected and is usually mild. If the skin is visibly scaly, apply a light non-oily moisturizer.
• Skin irritation is rarely severe. Occasionally, irritation means that product must be discontinued. Consider applying it less frequently.
• Contact dermatitis (red, dry, itchy skin) can be due to irritation or allergy. It can be treated with a topical steroid such as hydrocortisone cream (available at a pharmacy in New Zealand without a prescription).
• Rarely, serious allergic reactions to benzoyl peroxide, including anaphylaxis, have been reported.
• Bleaching of clothing. Make sure the benzoyl peroxide has completely dried before the treated skin touches clothes, towels or bedding. It is more likely to stain cotton and linen fabrics than polyester and fleece fabrics [1].