Finding a good sunscreen is important for healthy skin, but it can get confusing trying to figure out which one is best for you. According to WebMD, good sunscreen should help fend off both types of UV rays, UVB and UVA. While both types are linked to cancer, UVA does not cause sunburn but does age skin.
SPF is an indicator of how effective the sunblock is at blocking out UBV rays. SPF 15 is perfectly fine for the majority of people. For very fair skinned people, people will a family history of skin cancer, or other conditions, SPF 30 or greater would be more beneficial, but “contrary to what you might think, SPF 30 isn’t twice as strong as SPF 15. While SPF 15 filters out 93% of UVB, SPF 30 filters out 97%, only a slight improvement” (WebMD).
To combat UVA rays, SkinCancer.org suggests finding a sunscreen with the following ingredients: stabilized avobenzone, ecamsule or MexorylTM, oxybenzone, titanium dioxide, and zinc oxide.