Letrozole is a prescription medicine that may be used off-label to treat female infertility by inducing ovulation. Off-label use is when a provider prescribes a medication that has been studied and found to be safe and effective, but it is used for a different purpose than its approved use.
Letrozole is from a class of medications called aromatase inhibitors. It is approved by the U.S. Food and Drug Administration (FDA) for the treatment of certain types of breast cancer.
Letrozole Dosage for Infertility
The recommended starting dose of letrozole to induce ovulation is 2.5 mg once a day for 5 days, beginning between days 2 and 5 of menstrual bleeding. The medicine can be taken at any time during the day, but it should be taken at the same time each day. Food does not interfere with the medicine, so it can be taken before or after eating.
You are then monitored by various methods to determine if and when you are ovulating. Once ovulation occurs, your egg may be fertilized through timed sexual intercourse, intrauterine insemination or in vitro fertilization.
If pregnancy does not occur with the first cycle, the process may be repeated for more cycles and the letrozole dose may be increased by 2.5 mg increments up to 7.5 mg. How many cycles to try is a decision between you, your partner and your doctor.
Side effects
Because letrozole is used off-label in this situation, it is difficult to determine how common side effects are for this specific regimen. When letrozole is given to treat breast cancer (which may be for as long as five years), common side effects include:
- Hot flashes
- Muscle aches
- Flushing
- Headache
- Dizziness
- Bone pain