The Complete Guide to Sunscreen: SPF Explained

Sunscreen is the most important product in any skincare routine, yet it remains one of the most misunderstood. SPF, or Sun Protection Factor, measures how well a sunscreen protects against UVB rays — the primary cause of sunburn and a contributor to skin cancer. SPF 30 blocks approximately 97% of UVB rays, while SPF 50 blocks about 98%.

The choice between chemical and mineral sunscreens depends on your skin type and preferences. Chemical sunscreens absorb UV rays and convert them to heat, while mineral (physical) sunscreens sit on top of the skin and reflect UV rays. Mineral options are generally better for sensitive skin, while chemical formulas tend to be more lightweight and cosmetically elegant.

Regardless of which type you choose, proper application is crucial. Use about a quarter-teaspoon for your face and reapply every two hours, or immediately after swimming or sweating. No sunscreen provides 100% protection, so combine it with other sun-safe practices like seeking shade and wearing protective clothing.