Exemestane (Aromasin): a clear, practical guide

Cutting off estrogen production is a powerful way to slow certain breast cancers. Exemestane (brand name Aromasin) is an oral aromatase inhibitor used mainly in postmenopausal women with hormone receptor–positive breast cancer. If you’ve been prescribed exemestane, this page gives straightforward facts, common side effects, and useful everyday tips to make treatment easier.

How exemestane works and who takes it

Exemestane permanently blocks the aromatase enzyme, which makes most of the estrogen in postmenopausal women. That drop in estrogen helps stop growth of cancers that need estrogen to grow. Typical use includes adjuvant treatment after surgery, sometimes after several years of tamoxifen, or as part of advanced cancer care when appropriate.

Usual dose is 25 mg once daily by mouth. It’s intended for postmenopausal patients. If you’re premenopausal, doctors may add ovarian suppression before using exemestane. Always follow your oncologist’s plan—don’t switch doses or stop suddenly without checking in.

Side effects, monitoring, and practical tips

Common side effects are joint and muscle pain, hot flashes, fatigue, and vaginal dryness. Exemestane can lower bone density, so bone health is a big concern: expect baseline bone mineral density testing and periodic checks. Your team may recommend calcium, vitamin D, or bone-strengthening drugs like bisphosphonates or denosumab if your bone density drops.

Other things your doctor will watch: cholesterol changes and liver function in some cases. If you notice sudden severe bone pain, new swelling, or signs of liver trouble (yellowing skin, dark urine), contact your clinic quickly.

Drug interactions: exemestane is processed in the liver and can be affected by strong enzyme inducers (for example, some seizure meds or rifampin). Estrogen-containing products will counteract it, so don't use combined hormone patches or pills while taking exemestane unless your doctor clears them. Always tell your care team about prescription, over-the-counter meds, and supplements.

Simple daily tips: take the pill at the same time each day, with or without food. Manage joint pain with light exercise, warm showers, or acetaminophen after checking with your doctor. Keep up with bone-healthy habits—weight-bearing exercise, quit smoking, and limit alcohol. If nausea or sleep trouble shows up, your team can suggest adjustments or supportive meds.

Thinking about pregnancy or fertility? Exemestane is not safe in pregnancy and can harm an unborn baby. Discuss fertility preservation before starting if that’s relevant.

If something feels off or a side effect is hurting your daily life, call your oncology nurse or doctor. Small changes—like adding vitamin D, a bone scan, or switching supportive meds—can make a big difference in how tolerable treatment is.