Femara (generic name is Fempro with letrozole as an active substance) is an oral drug which can be an effective fertility treatment for women with ovulation problems, or for those with unexplained infertility.
This medication is in a class of drug called aromatase inhibitors.
Non-steroidal aromatase inhibitors, such as Anastrozole (Arimidex) and Letrozole (Femara, Fempro), inhibit the synthesis of estrogen via reversible competition for the aromatase enzyme.
When the aromatase enzyme is inhibited by the letrozole medication, estrogen levels are suppressed in young women. This results in the brain and pituitary gland increasing the output of FSH (follicle stimulating hormone).
Ovarian stimulation with the aromatase inhibitor letrozole has been proposed as one of the treatments for unexplained female infertility. In a multi-center study funded by the National Institute of Child Health and Development, ovarian stimulation with letrozole resulted in a significantly lower frequency of multiple gestation (i.e., twins or triplets) but also a lower frequency of live birth, as compared with gonadotropin but not with clomiphene citrate. In women that already ovulate on their own, treatment with Femara can result in development of multiple follicles and multiple eggs releasing, that can increase the chances for pregnancy as compared to release of a single egg with a natural menstrual cycle.
Letrozole has been used for ovarian stimulation by fertility doctors since 2001 because it has fewer side-effects than clomiphene citrate (Clomid) and less chance of multiple gestation. Femara (Fempro) stimulates ovulation, uses to assist with unexplained infertility. Femara is considered a second choice, and usually only prescribed by a doctor when Clomid is not working.
The most common dose of Femara is 2.5 mg of Letrozole per day on days five through nine of the menstrual cycle.
Letrozole for men
Letrozole (Fempro) can be used to treat male infertility and the induction of spermatogenesis in a man with NOA (nonobstructive azoospermia). Testis biopsy showed normal spermatogenesis following 4 months of letrozole therapy.