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Femara Side Effects
Although most people have no problems when taking Femara, side effects can occur during treatment with the medicine. A few commonly reported side effects include hot flashes, fatigue, and back pain. Potentially serious side effects of Femara include unexplained vaginal bleeding, signs of an allergic reaction, and difficulty breathing. If you experience these or other serious side effects, let your healthcare provider know right away.
As with any medicine, side effects are possible with Femara® (letrozole); however, not everyone who takes the medication will experience side effects. In fact, most people tolerate Femara quite well. If Femara side effects do occur, in most cases, they are minor and either require no treatment or are easily treated by you or your healthcare provider.
(This article covers many, but not all, of the possible side effects with Femara. Your healthcare provider can discuss a more complete list of Femara side effects with you.)
Common Side Effects of Femara
Femara has been studied thoroughly in clinical trials, in which a group of people taking the drug have side effects documented. This way, it is possible to see what side effects occur and how often they appear.
In these studies, the most common Femara side effects included:
- Hot flashes -- in up to 33.7 percent of women
- Fatigue or weakness -- up to 33.6 percent
- Increased sweating -- up to 24.2 percent
- Joint pain or arthritis -- up to 22 percent
- Headaches -- up to 20.1 percent
- Swelling or water weight gain -- up to 18.4 percent
- Back pain -- up to 18 percent
- Nausea -- up to 17 percent
- High cholesterol -- up to 15.6 percent (see Femara and High Cholesterol).
Some other common side effects (occurring in 2 to 15 percent of people) included:
- Dizziness
- Night sweats
- Cough
- Constipation
- Weight loss
- Weight gain (see Femara and Weight Gain)
- Diarrhea
- Vomiting
- Insomnia (see Femara and Insomnia)
- Breast pain
- Muscle pain
- The flu
- Urinary tract infections (UTIs or bladder infections)
- Broken bones
- Vaginal dryness or irritation
- Loss of appetite
- Indigestion or heartburn
- Drowsiness.
Written by/reviewed by: Kristi Monson, PharmD; Arthur Schoenstadt, MD
Last reviewed by: Kristi Monson, PharmD