Homosalate

Homosalate is a synthetic chemical sunscreen ingredient that is used in SPF products to protect again harmful ultraviolet (UV) radiation.

Chemical sunscreens function by absorbing UV light due to their chemical structure, which is in contract to physical sunscreens, such as zinc oxide and titanium dioxide. What makes physical sunscreens different is that they both absorb and reflect UV light.

Chemical sunscreens, like homosalate, have advantages to physical sunscreens, including that they are non-whitening when applied to the skin and they offer more lightweight protection.

One disadvantage to chemical sunscreens is their tendency to form reactive oxygen species (ROS) when exposed to UV light, which can be harmful to the skin and body. Homosalate specifically absorbs light with wavelengths between 295 and 315 nanometers, which is considered the UVB range of UV light.

UVB radiation penetrates the outer layer of skin, causes tanning and burning, and can lead to an increased risk of skin cancer. Therefore, using sunscreens that protect against UVB light is a critical part of sun protection.

Homosalate is a pale yellow liquid that is oil-soluble, useful for dissolving crystalline sunscreens, like avobenzone and ethylhexyl triazone, and is occasionally used as a fragrance.