Ishizawa Labs Shigaisen Yohou Moisturizing UV Serum SPF 50+ Versus Paula's Choice Resist Youth-Extending Daily Hydrating Fluid SPF 50

UVB (290-320 nm) rays emit more energy than UVA rays. They are capable of damaging DNA, causing sunburns and are thought to be linked to skin cancer.

The state of Hawaii has banned sunscreens containing octinoxate due to its potential impact on coral reefs. More research is needed to bridge gaps in this research. The European Union allows higher levels of octinoxate in sunscreens than the US and Australia.

Ethylhexyl Methoxycinnamate is oil soluble. It is not stable and may lose efficacy when exposed to sunlight.

Topically applied tocopherol has been shown to protect against UV damage by ramping up the skin's own natural defense enzymes.

It also acts as a skin conditioning agent; some studies show that regular topical use can improve the skin's water-binding capacity over 2-4 weeks.

This ingredient is especially loved for being a team player. When combined with Vitamin C, the photoprotective effect of both ingredients roughly doubles and the combo also helps reduce UV-induced DNA damage.

This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.

In formulations, it also serves as a stabilizer that helps protect other oxidation-prone ingredients from degrading.

Concentrations usually range from 0.1-1% in most leave-on products.