SUNSCREEN is the #1 way to fight aging, and skin cancer.

Experts say the best way to stay protected from the sun is to stay out of the sun during its hottest hours (generally 11am-3pm, or when it’s directly overhead), and to re-apply sunscreen every two hours. They will tell you to look for sunscreens with the ingredients of either Zinc Oxide, Titanium Dioxide, Avobenzene (parsol 1789), or Mexoryl. Zinc Oxide and Titanium Dioxide are physical blockers, while Avobenzene and Mexoryl and chemical blockers.

Q: What type of sunscreen should I use, and what ingredients should I look for?
A: There are so many types of sunscreen that selecting the right one can be quite confusing.
• Avobenzone (parsol 1789),
• Cinoxate
• Ecamsule
• Menthyl anthranilate
• Octyl methoxycinnamate
• Octyl salicylate
• Oxybenzone
• Sulisobenzone
• Titanium dioxide
• Zinc oxide           
BurnOut 18.6% Zinc Oxide Sunblock / SPF 32 for Sensitive Skin 
To get a bit technical, you want your sunscreen to protect you against UVA and UVB rays. UVA is what is responsible for aging your skin, giving you wrinkles, and skin cancer. UVB is what causes your skin to darken and burn. While all the information I read is a bit conflicting, here is a general idea of how the wavelengths of UVA and UVB breakdown:

UVB (burning) has a wavelength range (in nanometers) of:   
280-320
UVA (aging) has a wavelength range (in nanometers) of:      
320-400

To get the best sun protection, you want your sunscreen to contain ingredients that cover as wide a range as possible in the 280-400 spectrum. Here’s how a few of the best and most common sunscreen ingredients breakdown:

Zinc Oxide 290-380
Mexoryl 290-400
Avobenzene 340-375
Titanium Dioxide 290-340
Octinoxate and Octisalate 280-320
Oxybenzone 320-240

Now many sunscreens combine ingredients to cover a wider range of the spectrum. However, you can see that Zinc Oxide and Mexoryl cover the widest spectrum all by themselves, and they are photo-stable ingredients. This is extremely important, because it means your sunscreen won’t lose effectiveness an hour after you apply it like Avobenzene, for example, which is not photo-stable.  Neutrogena and some other companies use Helioplex, or other ingredients to make their Avobenzene more photostable. I haven’t experimented with these ingredients, but I doubt they are as photo-stable as Zinc Oxide or Mexoryl.
Many new sunscreen ingredients that are approved in Japan and Europe, such as Mexoryl XL, Tinosorb M, Tinosorb S, Uvinil T 150, Uvasorb HEB, and Parsol SLX, have not been approved by the FDA for use in new sunscreens in the United States.