Anastrozole: What it does and how to use it safely

Anastrozole is a pill that lowers estrogen in the body. Doctors prescribe it mainly to treat hormone receptor–positive breast cancer in postmenopausal women. By blocking the aromatase enzyme, anastrozole cuts estrogen production and slows the growth of estrogen-driven tumors. It is not a chemotherapy drug; it is targeted hormonal therapy.

Who should take anastrozole and who should not

If you're postmenopausal and your tumor tests positive for estrogen receptors, anastrozole is often part of the plan after surgery, radiation, or chemotherapy. Premenopausal women usually do not get it unless their ovaries are suppressed first. Never take anastrozole during pregnancy — it can harm a fetus. Talk to your doctor if you are breastfeeding, trying to conceive, or have severe liver disease.

How to take anastrozole in real life: The standard dose is 1 mg once a day, taken with or without food. Try to take it at the same time each day. If you miss a dose, take it as soon as you remember unless the next dose is near — then skip the missed one. Don’t double up. Keep pills in their original container away from heat and moisture.

Common side effects and what to expect: Many people feel joint pain, stiffness, or muscle aches. Hot flashes, sweating, fatigue, and mood changes are common too. Anastrozole can lower bone density over time, raising the risk of fractures. Less common effects include nausea, headache, and skin changes. Most side effects are manageable but tell your care team right away about severe or new symptoms.

Monitoring and simple precautions: Your doctor will check bone health with periodic DEXA scans and may recommend calcium, vitamin D, or bone-strengthening drugs if you’re at risk. Blood tests can monitor liver function and cholesterol. Mention all medicines and supplements you take — some drugs affecting hormones or strong enzyme inducers may alter how anastrozole works. Avoid estrogen-containing products, including some creams and supplements.

Practical tips for better tolerance

Keep moving: weight-bearing exercise helps bones and joints. Over-the-counter pain relievers can ease aches, but check interactions first. Dress in layers to handle hot flashes. Keep a symptom diary to discuss patterns with your doctor — that helps find solutions faster. If cost or access is a problem, ask about patient assistance, generics, or pharmacy options.

When to call your doctor: Seek care for sudden severe bone pain, signs of blood clots (shortness of breath, leg swelling), jaundice, or allergic reactions. For questions about fertility, sexual health, or mood changes, your care team can offer tailored help.

Generic options cut costs. Ask pharmacist for anastrozole generic, check prescription requirements, and avoid sites that ask for no prescription. If you have questions about brands, cost assistance, or drug interactions, your oncology nurse or pharmacist can help. Keep records of side effects and doses for clinic visits.