nordihydroguaiaretic acid
(NOR-dy-HY-droh-GWY-uh-reh-tik A-sid)
A drug put on the skin to treat growths caused by sun exposure. A form of nordihydroguaiaretic acid that is taken by mouth is being studied in the treatment of prostate cancer. Nordihydroguaiaretic acid is an antioxidant, and it may block certain enzymes needed for tumor growth. Also called Actinex, masoprocol, and NDGA.