α-hydroxy Tamoxifen is primarily used in research and clinical studies to investigate its role as an active metabolite of Tamoxifen. It is particularly significant in studying breast cancer treatment mechanisms, as it contributes to the anti-estrogenic effects that help inhibit the growth of estrogen receptor-positive breast cancer cells. Researchers utilize it to better understand the metabolic pathways and efficacy of Tamoxifen therapy. Additionally, it serves as a reference standard in analytical laboratories for the quantification and quality control of Tamoxifen and its metabolites in biological samples. Its application extends to exploring potential therapeutic benefits and side effects associated with Tamoxifen treatment.