This term is used for substances which make the skin sensitive and reactive to the sun's energy, especially light. Lemon, Lime, and Bergamot are examples of essential oils that are slightly photosensitive and should not be worn if sunbathing or in a sun lamp.

agents, such as certain oral medications, cosmetics and plants. that increase the sensitivity of cells of the skin to ultraviolet radiation from the sun.

is a light-activated drug, such as Visudyne and lemuteporfin.

A drug product that causes an adverse effect in the presence of UVA/UVB or visible light

A drug used in photodynamic therapy. When absorbed by cancer cells and exposed to light, the drug becomes active and kills the cancer cells.