Clomifene (INN) or clomiphene (USAN and former BAN) or Clomid or Clomifert is a selective estrogen receptor modulator (SERM) that increases production of gonadotropins by inhibiting negative feedback on the hypothalamus. It is used mainly for ovarian stimulation in female infertility due to anovulation (e.g., due to polycystic ovary syndrome). Clomiphene citrate is marketed under various trade names including Clomid, Serophene, and Milophene. Clomiphine citrate has been found very effective in the treatment of secondary male hypogonadism in many cases. This has shown to be a much more attractive option than testosterone replacement therapy (TRT) in many cases because of the reduced cost and convenience of taking a pill as opposed to testosterone injections or gels. Unlike traditional TRT it also does not shrink the testes and as a result can enhance fertility. Traditional TRT can render a man sterile. Because clomiphene citrate has not been FDA approved for use in males it is prescribed off-label. According to Professor Craig Niederberger, because this drug is now generic, no drug company would pursue FDA approval for use in men now because there would be no profit incentive. However, the single isomer of clomiphine "enclomiphene" under the brand name Androxal is currently under phase 2 trials for use in men.