Short answer: The Femara label dose is one 2.5 mg tablet by mouth once a day, with or without food. People with cirrhosis and severe liver impairment take 2.5 mg every other day. In early breast cancer the best length of treatment is not known; median treatment in the trials was 5 years. In advanced cancer it continues until the tumor progresses.
This is what the FDA label says. Follow your prescriber. Your prescriber may use a different dose or pace than the label's standard schedule.
What Femara is approved for: Femara is an aromatase inhibitor approved for postmenopausal women with breast cancer: as adjuvant (after-surgery) treatment of hormone receptor-positive early breast cancer, as extended adjuvant treatment after 5 years of tamoxifen, and as first- or second-line treatment of hormone receptor-positive or unknown advanced breast cancer (section 1).
Source
FEMARA (letrozole) tablets, for oral use, prescribing information. Novartis. DailyMed, version published June 15, 2026. DailyMed setid 82b77d74-085f-45ac-a7dd-1f5c038bf406
Femara is one 2.5 mg tablet taken by mouth once a day, without regard to meals (section 2.1).
The label does not set a time of day for the dose (section 2.1).
The table below is the label's schedule, from the Dosage and Administration section. Numbers are copied exactly; the section is in brackets.
| Situation | What the label says |
|---|---|
| Recommended dose | One 2.5 mg tablet administered once a day, without regard to meals |
| Adjuvant early breast cancer | Optimal duration unknown; median treatment duration was 5 years; discontinue at relapse |
| Extended adjuvant early breast cancer | Optimal duration not known; planned duration in the study was 5 years; discontinue at tumor relapse |
| Advanced breast cancer | Continue until tumor progression is evident |
| Mild to moderate hepatic impairment | No dosage adjustment recommended |
| Cirrhosis and severe hepatic dysfunction | Reduce dose by 50%: 2.5 mg administered every other day |
| Renal impairment, creatinine clearance ≥ 10 mL/min | No dosage adjustment required |
In the extended adjuvant study, median treatment was 60 months; 71% were treated for at least 3 years and 58% completed at least 4.5 years.
Taking Femara with tamoxifen 20 mg daily lowered letrozole blood levels by 38% on average. Clinical experience suggests Femara still works when started right after tamoxifen.
Women who could become pregnant have a pregnancy test before starting and use effective contraception during treatment and for at least 3 weeks after the last dose. Breastfeeding is avoided for the same period (section 8.2).
The Femara label gives no missed-dose instruction. Ask your prescriber or pharmacist what to do if a dose is missed.
More on this: missed a dose of Femara.
In Dose Track you set up Femara as a protocol with the dose and schedule your prescriber gave you. A protocol can hold dose steps, each with its own dose and length in days or weeks, so a step-up plan like the one on the label can be entered once and the app moves to the next step on its own. Reminders follow the schedule, and every dose is logged with the date and time, so you can see which step you are on and when your last dose was. The app follows what you enter; it does not choose or change a dose.
This page is what the FDA label says, in plain words. It is not medical advice. Follow your prescriber, and ask them or your pharmacist about anything here.