Sunscreen contains active ingredients that help protect the skin from UVA and UVB rays. There are two classes of sunscreen filters: chemical and mineral (or physical). Chemical sunscreens absorb UV rays before they reach the skin, while mineral sunscreens provide a physical block that protects against these rays.
When picking out a new sunscreen, you’ll want to look for a product that is specifically formulated for your skin type so that it works well with your skin. In general, people with sensitive skin tolerate mineral sunscreens better than chemical sunscreens, but anyone can use either type. You should also consider whether you’re looking for a daily sunscreen or one for working out outside and swimming, because this will determine whether you’ll need a water-resistant formula or not.
When adding a new product to your routine, it’s smart to do a patch test to avoid any negative reactions. To patch test your sunscreen, apply a small amount to clean skin on the forearm, and avoid washing the area for 24 hours. After 24 hours, see if there are any signs of irritation.
You should use sunscreen daily, even when you aren’t spending a ton of time outside, and even if it’s cloudy. UV rays are able to penetrate through windows and clouds, so daily use is ideal for maximum protection.
You’ll want to use about an ounce of sunscreen for the entire body. For the face, ears, and front of neck, you’ll want to use about a quarter teaspoon.
Sunscreen won’t directly treat acne or acne scars, but it does play a role in the healing process of post-inflammatory hyperpigmentation (AKA discolored acne marks). Wearing sunscreen daily helps ensure these dark spots don’t get darker, and therefore will help speed up the process of fading these marks.