For over half a century, benzoyl peroxide (BPO) has been considered a titan in the arena of anti-acne treatments. From cleansers to body washes, spot treatments to lotions, the number of products incorporating this stellar ingredient continue to grow.
Let’s take a closer look at why BPO remains a force to reckon with in the fight against acne.
What is benzoyl peroxide?
Benzoyl peroxide is a chemical compound that has antiseptic, keratolytic, comedolytic, anti-inflammatory, and irritant properties. This white, crystalline solid is usually suspended in a base to make it easier to spread on the skin.
BPO can be used alone in varying concentrations, or in combination with other active ingredients such as antimicrobials or retinoids for a synergistic action.
How does BPO work?
Benzoyl peroxide works primarily by inhibiting the growth of acne-causing bacteria. Remember that Propionibacterium acnes, the bacteria most associated with zits, is anaerobic. That’s why a clogged pore is the best place for it to multiply. In a nutshell, benzoyl peroxide creates oxygen inside the pore, which is toxic to the bacteria.
When BPO is administered on the skin, it breaks through the epidermis and works its magic deeper within the pores. In the process of metabolizing the BPO, oxygen is produced and kills the bacteria. It’s pretty good at it too, even when compared to antibacterials such as erythromycin and clindamycin. And unlike these compounds, use of BPO does not lead to resistant strains of P. acnes. Studies report over 95% reduction in the amount of bacteria after one week of twice-a-day BPO use. This translated into a noticeable reduction in the number of spots within a few weeks to a few months of use.
In addition to killing the inflammation-triggering bacteria, BPO also has keratolytic effects. It helps break down the keratin that plugs up our pores, which is the reason why anaerobic bacteria thrive there in the first place.
What are the side effects of BPO?
Benzoyl peroxide’s keratolytic effect has a tendency to cause drying for the first few weeks of use. There are several ways to work around this. One good option is to try using a lower strength product. Studies show that 2.5% BPO has the same efficacy but less reported side effects than 5% or 10%. You can also build up usage over time--say use it thrice a week for the first week, then slowly increase frequency until your skin is able to tolerate daily use. And the best way to help improve dryness is to use a mild, non-comedogenic moisturizer once BPO has dried and been fully absorbed into the skin.
Because BPO causes drying and peeling, it can make your skin more sensitive to the sun. Make sure to use a broad-spectrum sunscreen or moisturizer with at least SPF 30 to help protect from harmful rays.
The reactive oxygen species produced by BPO is proven to kill off bacteria, but at the same time, it depletes skin’s store of Vitamin E. You can restore the supply of this important antioxidant by taking oral supplements or using topical products with Vitamin E.
BPO is also known to bleach clothes. You have to make sure that your skin is completely dry before putting on clothes or lying on sofas and beds.
Note that there is a small percentage of the population who are allergic or reactive to BPO. While a reaction is normal when you first start using the product, you should discontinue use if there is swelling, persistent crustiness, and redness. This might not be the best product for you, so consult your dermatologist on other options.
How can I incorporate BPO into my routine?
Benzoyl peroxide can be used as a leave-on or a wash-off product and is available over-the-counter in most countries. Leave-on products such as creams, gels, spot treatments, and lotions are usually found at lower concentrations (2.5% to 5%), as the length of time it stays on the skin strengthens the effect.
Wash-off products like cleansers or body washes often have higher concentrations and follow the 20-10 rule--that is, give the formulation at least 20 seconds to rest on your skin, then wash it off after 10 seconds.
There are 2-in-1 products that include benzoyl peroxide and another anti-acne treatment with a different mechanism of action. You can find products that combine BPO and an antibiotic, or BPO and a retinoid. Because its active ingredients target different factors in the pathogenesis of acne, these products are typically more effective.
If you have an existing anti-acne routine and want to incorporate BPO into it, make sure to do your research first. BPO causes irritation, so using it in conjunction with other irritating products can do more harm than good. Many people space out their actives, using one strong chemical in the morning, and a different one at night. It’s best to use BPO with mild, non-comedogenic products to avoid further irritation. And don’t forget to protect your skin with sunscreen!
Because BPO does not cause antimicrobial resistance, it can be used for long-term acne therapy and post-breakout maintenance.
Conclusion
With its antiseptic and keratolytic properties, inability to cause resistance, and good safety profile, there’s no wonder that dermatologists always reach for BPO for their acne-prone patients. As in any acne medication, you should be in it for the long haul. Even the best acne treatments will take time to work. With consistent and proper use, benzoyl peroxide stands a high chance of being The Product that will banish your acne.
This content is for general information only and is not a substitute for medical advice.
Resources:
Del Rosso J. Q. (2008). Benzoyl peroxide cleansers for the treatment of acne vulgaris: status report on available data. Cutis, 82(5), 336–342.
Matin T, Goodman MB. Benzoyl Peroxide. [Updated 2020 Mar 16]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537220/
Mills, O. H., Jr, Kligman, A. M., Pochi, P., & Comite, H. (1986). Comparing 2.5%, 5%, and 10% benzoyl peroxide on inflammatory acne vulgaris. International journal of dermatology, 25(10), 664–667. https://doi.org/10.1111/j.1365-4362.1986.tb04534.x
Oon, H. H., Wong, S. N., Aw, D., Cheong, W. K., Goh, C. L., & Tan, H. H. (2019). Acne Management Guidelines by the Dermatological Society of Singapore. The Journal of clinical and aesthetic dermatology, 12(7), 34–50.
Valacchi, G., Rimbach, G., Saliou, C., Weber, S. U., & Packer, L. (2001). Effect of benzoyl peroxide on antioxidant status, NF-kappaB activity and interleukin-1alpha gene expression in human keratinocytes. Toxicology, 165(2-3), 225–234. https://doi.org/10.1016/s0300-483x(01)00430-9
https://www.acne.org/how-does-benzoyl-peroxide-work-in-the-skin.html
