Homosalate is a chemical UV filter that absorbs UVB rays to protect skin from sun damage. It's commonly used in sunscreens and is often combined with other UV-blocking ingredients for broader protection.
Benefits
Absorbs UVB radiation to help prevent sunburn
Lightweight and works well in various sunscreen formulations
Allows for flexible product formats (lotions, sprays, etc.)
Potential concerns
Systemic absorption occurs—research shows it enters the bloodstream at levels exceeding FDA's 0.5 ng/mL threshold after a single application
Long-term effects of systemic absorption are not yet fully understood
May cause skin irritation or allergic contact dermatitis in sensitive individuals
Science: A 2020 FDA-led clinical trial found that homosalate, along with five other common sunscreen actives, is systemically absorbed and exceeds the FDA's recommended safety threshold (0.5 ng/mL) after a single application. While this absorption is documented, the clinical significance and long-term health implications remain under investigation.
Octisalate is a chemical UV filter used in sunscreens to absorb ultraviolet (UVB) light and help protect skin from sun damage. It works by converting UV rays into heat that dissipates from the skin.
Benefits
Provides UVB sun protection
Lightweight and less visible on skin than mineral filters
Compatible with many other skincare ingredients
Potential concerns
Systemic absorption detected in blood after single application; all participants exceeded FDA's 0.5 ng/mL threshold on day 1
Long-term health effects of systemic absorption remain unclear and require further study
May cause skin irritation or allergic contact dermatitis in sensitive individuals
Science: A 2020 FDA-led clinical trial found that octisalate is absorbed systemically into the bloodstream after topical sunscreen application, with measurable plasma concentrations exceeding regulatory thresholds. The long-term safety implications of this absorption are not yet fully established, and additional research is ongoing.
