Nolvadex (tamoxifen citrate) is an oral anti-oestrogen for breast cancer, and the world's largest selling breast cancer treatment. Nolvadex has more than 10 million patient years of use in the treatment of early and advanced breast cancer in pre- and post-menopausal women. Additionally, in 1998, the US Food and Drug Administration (FDA) approved Nolvadex (tamoxifen citrate) for the reduction of the incidence of breast cancer in women at high risk of developing the disease.

Nolvadex is the first drug to be approved in the USA in this indication. The FDA also approved a further new indication for Nolvadex for the reduction of contralateral (in the opposite breast) breast cancer. Trials for paediatric use of Nolvadex are ongoing.