Afimoxifene, also known as 4-hydroxytamoxifen, is the active metabolite of tamoxifen and acts as a selective estrogen receptor modulator (SERM). It is primarily under investigation for the topical prevention and treatment of breast cancer, especially estrogen receptor-positive cases in high-risk postmenopausal women. By locally antagonizing estrogen effects in breast tissue, it inhibits the proliferation of estrogen-dependent cancer cells while reducing systemic exposure and side effects compared to oral tamoxifen.

In addition to oncology, afimoxifene is being studied for managing other estrogen-related conditions, including endometriosis and uterine fibroids, leveraging its partial agonist/antagonist profile for tissue-selective estrogen modulation.

Ongoing research also explores its role in preventing postmenopausal osteoporosis through preservation of bone mineral density, offering potential benefits for both cancer risk reduction and skeletal health.

As a specialty pharmaceutical compound, afimoxifene is supplied in high purity for research, drug development, and clinical applications in estrogen-mediated disorders.