Sunscreens contain a combination of organic and/or inorganic chemicals that absorb or reflect UV rays, preventing them from penetrating the skin. The two main types of UV radiation that are of concern are UVA and UVB rays. UVA radiation can penetrate deeper into the skin and contribute to aging and wrinkling, while UVB radiation causes sunburn and can lead to skin cancer.

Sunscreens are available in various forms, including lotions, creams, sprays, gels, and sticks. Sunscreens work by absorbing, reflecting, or scattering UV radiation, and are classified into two main types: chemical and physical sunscreens. Chemical sunscreens contain organic compounds that absorb UV radiation and convert it into less harmful energy, while physical sunscreens contain inorganic particles that reflect or scatter UV radiation away from the skin. Some sunscreens may also contain antioxidants, which can help neutralize the free radicals generated by UV radiation and prevent oxidative damage to skin cells.

While sunscreen can be effective in protecting against sun damage, it is not a substitute for other sun protection measures, such as wearing protective clothing, seeking shade, and avoiding the sun during peak hours.

This learning module will cover the different types of sunscreens available, including physical and chemical sunscreens, their mechanisms of action, indications, and potential adverse effects. Additionally, this module will also provide guidance on the appropriate use of sunscreens, including their application, reapplication, and storage.

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1. Bolognia, J., Cerroni, L., & Schaffer, J. V. (2018). Dermatology. Philadelphia: Elsevier.

2. Raffa RB, Pergolizzi JV, Jr., Taylor R, Jr., Kitzen JM. Sunscreen bans: Coral reefs and skin cancer. J Clin Pharm Ther. 2019;44(1):134-9.
3. Wolverton, S. E. (2021). Comprehensive dermatologic drug therapy. Edinburgh: Saunders.