4’-hydroxy Tamoxifen is primarily used in research and clinical settings as an active metabolite of Tamoxifen. It plays a crucial role in studying breast cancer treatments due to its ability to bind to estrogen receptors and inhibit estrogen-mediated cell proliferation. This makes it a valuable tool in understanding the mechanisms of hormone-dependent cancers. Additionally, it is utilized in laboratory studies to investigate the efficacy and resistance patterns of anti-estrogen therapies. Its application extends to the development of targeted cancer therapies, helping researchers design more effective drugs with fewer side effects.