My doctor prescribed letrozole to help me ovulate. How does it work and what side effects are normal?

Letrozole is an oral medicine originally used in breast cancer treatment that is now widely used to help women ovulate, especially those with PCOS. It temporarily lowers estrogen levels, which prompts the brain to release more FSH, the hormone that stimulates follicles to grow in the ovaries. It is usually taken for five days early in the cycle, as your doctor has advised. Many guidelines now recommend it as a first-line option for ovulation induction in PCOS. Follicle scans (follicular monitoring) help your doctor check whether a follicle is growing, decide when ovulation is likely, and watch for more than one follicle growing, which raises the chance of twins. Common side effects are usually mild: hot flushes, headache, tiredness, dizziness, bloating, breast tenderness and mood changes. Take it exactly as prescribed and don't adjust the dose or duration on your own. Contact your doctor if you have severe abdominal pain, significant bloating, a very heavy or unusual bleed, severe headache or visual changes. Also tell them if you miss doses or ovulation isn't seen on scans, because the dose or approach may need changing. Use it only under a doctor's supervision and with monitoring.