Clomid, also known as Clomiphene, is a selective estrogen receptor modulator (SERM) commonly used in both fertility treatments and post-cycle therapy (PCT) to restore natural testosterone production. It works by blocking estrogen receptors in the hypothalamus, which stimulates the release of gonadotropins, promoting the production of testosterone in the testes. Clomid is particularly favored in bodybuilding to help restore hormonal balance and prevent side effects such as testicular shrinkage or low testosterone after anabolic steroid cycles.