A Practical Update on Benzoyl Peroxide

Key Takeaways

• Benzoyl peroxide remains a foundational acne therapy, but its potential degradation into benzene—especially under heat exposure—introduces important safety considerations. 
• Benzene contamination varies significantly across formulations, suggesting that manufacturing processes, ingredient selection, and storage conditions influence risk. 
• Current evidence indicates low or undetectable benzene levels in most products, and clinical risk appears reassuring; however, long-term safety data remain limited and warrant further study. 
• Risk mitigation strategies (including proper storage, avoiding heat exposure, monitoring recalls, and individualized risk-benefit assessment) are essential while preserving therapeutic use.

Benzoyl peroxide remains a cornerstone of acne therapy due to its efficacy and its role in preventing antibiotic resistance. However, its potential to degrade into benzene—particularly under conditions such as heat exposure—raises important safety considerations, given benzene’s status as a known human carcinogen.¹ We addressed these in a recent JAMA Dermatology article and will highlight key points here.²

VARIABILITY

Current evidence suggests that benzene contamination is not uniform across products. Significant variability exists between brands and formulations, indicating that manufacturing processes, ingredient selection, and storage conditions all play critical roles. For example, formulations involving higher processing temperatures or certain excipients may promote benzene formation, whereas stabilizing agents such as antioxidants may reduce it. There appear to be legitimate opportunities for manufacturers to improve product design through steps such as minimizing heat exposure during production, ensuring purity of raw materials, and implementing strict temperature controls during storage and distribution.

MONITORING IS CRITICAL

While most products tested showed undetectable or minimal benzene levels, a subset contained concerning amounts. These findings demonstrate the need for ongoing surveillance, greater transparency from manufacturers, and rigorous, standardized testing. We advocate for routine benzene monitoring and public reporting of results to maintain consumer confidence and ensure accountability.

UNCERTAIN CLINICAL RISK

Despite these concerns, the clinical risk associated with benzoyl peroxide use remains uncertain but generally reassuring. Existing epidemiologic studies have not demonstrated increased blood benzene levels or higher cancer risk among users, although these studies may not capture risks limited to specific formulations or long-term exposures. Signals from adverse event reporting systems further support the need for more definitive research. Accordingly, we emphasize the importance of prospective, long-term studies that evaluate both systemic benzene exposure and cancer outcomes, with attention to differences across product types and usage patterns.

A USEFUL TREATMENT

The potential risks of benzoyl peroxide must be considered in the broader therapeutic context. For many patients, particularly those with moderate acne, benzoyl peroxide is integral to effective treatment regimens. Avoiding it may necessitate alternative therapies such as oral antibiotics, hormonal treatments, or isotretinoin, each of which carries its own risks. Thus, risk-benefit decisions must remain individualized and clinically nuanced.

PRACTICAL STRATEGIES

Until more is known, we propose practical strategies to mitigate potential risk. Patients should avoid using expired or heat-exposed products, consider replacing products regularly, and be cautious with storage and shipping conditions. Refrigeration and sun protection may offer additional safeguards, though further evidence is needed. Clinicians should remain informed about recalls and counsel patients accordingly.

CONCLUSION

While benzoyl peroxide continues to be a highly effective and essential acne treatment, the issue of benzene formation warrants careful attention. The observed variability across products suggests that minimizing benzene exposure is an achievable goal. Through coordinated efforts among manufacturers, regulators, clinicians, and researchers, we can enhance product safety while preserving the therapeutic benefits of this foundational treatment. n

1. Kucera K, Zenzola N, et al. Evaluation of benzene presence and formation in benzoyl peroxide drug products. J Invest Dermatol. 2025;145(5):1147-1154.e11. Doi:10.1016/j.jid.2024.09.009.  

2. Barbieri JS, Bunick CG. Benzoyl peroxide-containing products and benzene: where are we now after recalls, and how should we move forward? JAMA Dermatol. 2025;161(8):791-792. Doi:10.1001/jamadermatol.2025.1694. 

Christopher G. Bunick, MD, PhD

• Associate Professor, Department of Dermatology and Program in Translational Biomedicine, Yale School of Medicine
  New Haven, CT

John S. Barbieri, MD, MBA

• Associate Professor, Department of Dermatology, Brigham and Women’s Hospital
  Boston, MA