Benzophenone-d5 is the deuterium labeled Benzophenone (HY-Y0546). Benzophenone is an endogenous metabolite. Benzophenone is a photosensitizer, that absorbs UV light, transfers its energy to DNA, and triggers DNA damage. Benzophenone can be used as the fragrance enhancer, ultraviolet curing agent, additive in plastics, or the flavor ingredient. Benzophenone can also be used in the manufacturing of insecticides, agricultural chemicals, hypnotics, antihistamines, and other pharmaceuticals. Benzophenone exhibits certain carcinogenicity in mouse/rat models under long term exposure. Benzophenone exhibits estrogenic activity[1][2].