What is Clomid?
Clomiphene citrate is a synthetic medication that affects the way in which a woman ovulates.

What makes it work?
Chemically, Clomiphene looks somewhat like estrogen. Like all hormones, estrogen works by occupying a receptor in different parts of the body. This occupied receptor then sends a signal telling that organ to do something. For example, in the brain estrogen directs the release of FSH, which controls the ovary's development of a mature egg. In the uterus, estrogen directs the thickening of the lining. Clomiphene blocks estrogen's attachment to its receptor.

How is this beneficial?
Clomiphene affects fertility in a positive way by tricking the body into thinking that less estrogen is present than there really is. The body responds by releasing greater amounts of FSH. In women who do not usually ovulate, this extra stimulation can cause ovulation to occur and make a pregnancy possible. In women who usually do ovulate, the clomiphene can produce extra mature eggs, or theoretically improve the maturation of the eggs that are released.

Does clomiphene have any negative effects on fertility?
It can. By blocking estrogen's activity in the uterus, the lining may be inadequately prepared for implantation of the embryo. Many women also find that their cervical mucous suddenly becomes hostile to sperm penetration.

How well does clomiphene work?
In women who need clomiphene to ovulate, the pregnancy rates are very high, as much as 33% per cycle for the first three cycles. In women who normally ovulate the rates are lower, and depend on many other factors, chiefly age, condition of the female reproductive tract and the male factor.