Lupron, Cetrotide, and Orgalutran down-regulate the reproductive hormone system, resulting in profoundly low levels of FSH and LH. Ovulation cannot occur while taking these products unless hCG or LH is administered. Normally, a spike of LH causes ovulation 36 hours later; however, this spike cannot occur in women taking Lupron, Cetrotide, or Orgalutran. An injection of hCG or LH is given and egg retrieval is scheduled accordingly.