Key takeaways
Letrozole (Femara) and Clomiphene (Clomid) are both prescription medications that can be used to help with fertility, but they work differently and have important differences. Letrozole is an aromatase inhibitor mainly used to treat breast cancer in postmenopausal females, but is sometimes used off-label to help females become pregnant. Clomiphene, on the other hand, is a selective estrogen receptor modulator (SERM) that is FDA-approved to treat female infertility by causing ovulation. Letrozole is taken daily, while Clomiphene is taken for 5 days during the menstrual period. Letrozole side effects include hot flashes and joint or muscle pain, while clomiphene can cause hot flashes, bloating, and stomach upset. Letrozole can raise cholesterol levels and weaken bones over time, whereas clomiphene can lead to ovarian hyperstimulation syndrome if used long-term.
