The most common side effects of tamoxifen are symptoms of menopause.

Keep in mind these side effects may also be caused by other conditions. Many women do not experience all symptoms. In general, symptoms can be successfully treated with over-the-counter medication. Please talk with your doctor about possible side effects and how to manage them:

Common side effects:

• Hot flashes and night sweats
• Irregular periods or spotting
• Loss of sex drive
• Vaginal dryness or itching
• Pain during sex
• Fatigue

Talk with your doctor if any of these symptoms become severe or do not go away, s/he can recommend how to treat them.

Rare side effects:

• Blood clots (legs and lungs)
• Bone loss (premenopausal women only)
• Cancer of the uterus (endometrial cancer)
• Cataracts
• Stroke
• Mood swings, depression

Call your doctor immediately if you are experiencing any of the following rare symptoms.

• Pain or pressure in the pelvis
• Leg swelling or tenderness
• Chest pain
• Shortness of breath
• Weakness, tingling, or numbness in your face, arm or leg
• Difficulty speaking and understanding
• Sudden vision problems
• Dizziness
• Sudden severe headache

Sources:

American Cancer Society, 2023. Treating Breast Cancer: Hormone Therapy for Breast Cancer.

National Cancer Institute, 2022. Hormone Therapy for Breast Cancer.

Susan G. Komen, 2024. Side Effects of Tamoxifen.