These fertility medications contain a hormone called follicle stimulating hormone that is normally produced by the pituitary gland which is located at the base of the brain. The FSH can be made in the lab using recombinant DNA technology or extracted from urine.
FSH stimulates the eggs to grow and when given in higher doses can overcome the body's normal mechanisms that prevent the release of more than one egg which can in turn lead to multiple births.
Human menopausal gonadotropins are another type of inject able fertility medication which contain not only FSH, but another pituitary hormone called luteinizing hormone, or at least a hormones that function like LH. Like Bravelle it is extracted from urine and must be reconstituted fresh from a powder each day.
hCG is the hormone produced by pregnant women that we measure in a pregnancy test. Because hCG works in a similar way to LH which triggers ovulation, hCG can be used to trigger ovulation. Injections of hCG are used to trigger release of the eggs for women undergoing IVF, IUI and ovulation induction