Acne and Benzoyl Peroxide Damage
Benzoyl Peroxide Cautions:
Benzoyl peroxide does kill bacteria, including P. acnes, but the mode of action to kill the bacteria can cause other problems. Peroxides, including benzoyl peroxide and hydrogen peroxide, have an unstable bond between two oxygen atoms. As the oxygen bond breaks the hydrogen peroxide creates free radicals that kill the P. acnes bacteria by destroying the cell wall.
Benzoyl peroxide generates free radicals in the skin. Its effect is similar to unprotected sun exposure. The redness of the skin (erythema), caused by sun exposure and benzoyl peroxide, are both the result of free radicals (oxidative stress) upon the skin. Repeated sun exposure or benzoyl peroxide use generates free radicals that damage the skin’s structure and cellular DNA, resulting in premature aging of the skin. The extent of the damage and aging from benzoyl peroxide is determined by the concentration of benzoyl peroxide, the frequency of application and the duration of its use.
Because benzoyl peroxide generates free radicals it interferes with, and slows, the healing process. The red and brown marks that are a part of the acne healing process may last weeks longer when benzoyl peroxide is a regular part of the daily regimen.
Benzoyl peroxide has been linked to cancer for a number of years and many research journal entries state “benzoyl peroxide is a free radical-generating skin tumor promoting agent.” Performing a word search of the words “benzoyl peroxide cancer” in PubMed in the National Library of Medicine produces 102 articles from medical publications dealing with research aspects of benzoyl peroxide and cancer. About two-thirds of the research supports linkage between benzoyl peroxide and skin cancer.
In 1995 the FDA changed benzoyl peroxide from a Category I (safe) to a Category III (safety is uncertain) ingredient and stated this action was based on new information that raised a safety concern regarding benzoyl peroxide as a tumor promoter. Additionally, the FDA charged manufacturers with the responsibility of providing this information to consumers so they could make educated decisions.
In 2011 the Food and Drug Administration (FDA) issued a final rule to include benzoyl peroxide as a generally safe active ingredient in over-the-counter (OTC) topical acne drug products. In addition, this final rule includes new warnings and directions required for OTC acne drug products containing benzoyl peroxide. The FDA is requiring new labeling on the cartons of products that contain benzoyl peroxide. The boxes will include warnings to avoid unnecessary sun exposure, to not use the product on very sensitive skin, and to keep the product away from the eyes, lips, and mouth. Consumers also will be cautioned that benzoyl peroxide can bleach hair or dye fabric. The label also will recommend that users wear a sunscreen.
The FDA did not find BPO to be a genotoxic substance, which basically means they do not believe that it damages DNA. They go on to add that BPO has been shown in research to create oxidative damage.
They did not find BPO to be carcinogenic. They state: “We have reviewed a number of animal studies examining the carcinogenic potential of benzoyl peroxide and conclude that benzoyl peroxide is not a carcinogen.”
Benzoyl peroxide has been associated with premature aging and dehydrated skin since it causes irritation to occur. Post-inflammatory hyperpigmentation (PIH) is a characteristic of acne, and benzoyl peroxide does little to help. It can create significantly more hyperpigmentation, especially in medium to darker skin because of the irritation that it can cause. Benzoyl peroxide can cancel out the effects of sun screens and make the skin more sensitive to the sun.
In summary, benzoyl peroixde does kill bacteria in the very short term, but it’s effects on premature aging, post-inflammatory hyperpigmentation, oxidative damage, free radical stress, bleaching properties, sun sensitivity and erythema make an educated skin care professional question its use when there are superior ingredients available.
As noted biochemist Glen Lockhart stated “If a client has been using benzoyl peroxide for several months, or years, and they have had little or no improvement, why would an esthetician believe that using another brand name of benzoyl peroxide suddenly have different results?”