Clomid© (clomiphene citrate)
Clomid was one of the first effective infertility medications discovered. Clomid has been used for years to induce ovulation in many women who have irregular or absent periods.
Clomid works at an area of the brain called the hypothalamus. The hypothalamus is located directly under the pituitary gland and is responsible for regulating the production of follicle stimulating (FSH) and luteinizing hormones (LH). The hypothalamus produces gonadotropin releasing hormone (GnRH) which signals the pituitary to increase its production of FSH and LH. FSH stimulates the development of eggs within the ovarian follicles on the ovaries.
The hypothalamus monitors the levels of various hormones, including estrogen, through a complex biofeedback mechanism. When estrogen levels are below a certain threshold the hypothalamus releases more GnRH thus signaling the pituitary to increase FSH production. Clomid works at the hypothalamus by “binding” estrogen receptors thus making measured estrogen levels lower. Clomid also raises the levels of LH.
Clomid is usually administered for five days at 50 mg/day and if ovulation does not occur the dose is increased to 100 mg/day. At higher doses, such as 150 mg/day, the treatment duration is often increased to 8 days. Once ovulation occurs on Clomid there is no advantage to increasing the dosage since the ovaries are not directly stimulated.
There are numerous studies indicating that pregnancy is most likely to occur during the first three ovulatory cycles on Clomid. Roughly 80% of women will ovulate, half of which get pregnant. There is no advantage to continuing therapy beyond six months and other treatment options should be explored. Follicle stimulating hormone with intrauterine insemination is often the next step.
Clomid can produce side effects including hot flashes, vaginal dryness, visual disturbances, nausea, dizziness, and ovarian enlargement but is generally very well tolerated. Many women also experience diminished cervical mucous while on Clomid. See the manufacturer's website for a complete discussion.