Comprehensive medication guide to Anastrozole including estimated pricing, availability information, side effects, and how to find it in stock at your local pharmacy.
Estimated Insurance Pricing
$0–$30 copay for generic anastrozole on most commercial and Medicare Part D plans; Tier 1–2 on most formularies; prior authorization rarely required for generic.
Estimated Cash Pricing
$9–$258 retail for generic anastrozole per 30-day supply; as low as $5–$9 with a GoodRx coupon at participating pharmacies, or $13 with a SingleCare coupon.
Medfinder Findability Score
82/100
Summarize with AI
On this page
Anastrozole is a prescription medication used to treat hormone receptor-positive (HR+) breast cancer in postmenopausal women. It is sold under the brand name Arimidex (made by AstraZeneca), though affordable generic versions are widely available from multiple manufacturers. Anastrozole belongs to a class of drugs called aromatase inhibitors.
The drug is FDA-approved for three indications: adjuvant treatment of early HR-positive breast cancer in postmenopausal women (typically 5 years post-surgery), first-line treatment of advanced or metastatic HR-positive breast cancer, and second-line treatment after tamoxifen failure. It is also used off-label for breast cancer chemoprevention in high-risk women and for other estrogen-driven conditions.
Anastrozole is taken as a 1 mg oral tablet once daily, with or without food. Most women take it for 5–10 years as part of their breast cancer adjuvant therapy. It is not a controlled substance.
We have a 99% success rate finding medications, even during nationwide shortages.
Need this medication?
Anastrozole is a selective, non-steroidal aromatase inhibitor. It works by blocking the aromatase enzyme — a biological catalyst that converts androgens (male hormones) into estrogen in peripheral tissues such as fat, muscle, skin, and liver. In postmenopausal women, this peripheral aromatization is the primary source of circulating estrogen.
By blocking aromatase, anastrozole reduces serum estradiol levels by approximately 80–96% in postmenopausal women. This dramatic reduction deprives hormone receptor-positive breast cancer cells of the estrogen they require to grow and divide. The inhibition is reversible — when anastrozole is stopped, aromatase activity and estrogen levels gradually return to baseline.
Unlike tamoxifen (which blocks estrogen from binding to receptors), anastrozole prevents estrogen from being made in the first place. Anastrozole has no significant effect on adrenal corticosteroid or aldosterone production at the standard 1 mg daily dose. It reaches steady-state plasma concentrations within approximately 7 days of once-daily dosing, with a half-life of 40–50 hours.
1 mg — tablet
Standard adult dose for all FDA-approved indications: 1 mg orally once daily, with or without food. Only available strength.
Anastrozole is generally well-supplied in the United States. As of 2026, there is no active FDA-listed national shortage. Multiple generic manufacturers — including Teva, Cipla, Accord Healthcare, Eugia Pharma, and Zydus Pharmaceuticals — produce anastrozole, providing meaningful supply chain redundancy. Generic anastrozole carries a findability score of 82/100, reflecting that it is widely stocked at most major pharmacies with only minor, occasional local inventory gaps.
However, temporary localized stock-outs do occur at individual pharmacies — typically resolving within days. If your regular pharmacy is out of stock, hospital outpatient pharmacies, Walmart, Costco, and mail-order pharmacies are reliable alternatives. High-volume pharmacies tend to maintain the best inventory of anastrozole due to its status as a common long-term maintenance medication.
If you're having trouble finding anastrozole at your pharmacy, medfinder calls pharmacies near you to check which ones have your medication in stock and texts you the results — saving you the time and frustration of calling around yourself.
Anastrozole is not a controlled substance, so any licensed prescriber can write a prescription for it without special DEA registration. The drug is primarily prescribed in the context of breast cancer care.
Medical oncologists (most common prescribers for initial and ongoing breast cancer treatment)
Breast oncologists and surgical oncologists
OB/GYNs and gynecologic oncologists (for co-management and off-label uses)
Primary care physicians (PCPs) for maintenance therapy once initiated by an oncologist
Nurse practitioners and physician assistants in oncology practices
Telehealth is available for anastrozole prescription renewals in established patients. Initial prescriptions for new breast cancer diagnoses are typically initiated in person by an oncologist after staging and treatment planning. Telehealth platforms with oncology services are expanding, making follow-up and renewal visits increasingly accessible.
No. Anastrozole is not a controlled substance and has no DEA schedule. It is classified as a prescription-only medication, but it does not require a DEA-licensed prescriber, and there are no restrictions on how many refills can be prescribed. Any licensed prescriber — including physicians, nurse practitioners, and physician assistants — can prescribe anastrozole.
Patients on long-term anastrozole therapy can typically receive 90-day supplies with multiple refills, which makes it much easier to maintain an adequate supply compared to controlled substances that require monthly prescriptions. This non-controlled status also makes telehealth prescription renewals straightforward for established patients.
Anastrozole's side effects are largely related to its mechanism of dramatically lowering estrogen levels. Common side effects include:
Hot flashes
Joint pain and stiffness (arthralgia)
Fatigue and weakness
Nausea
Headache
Mood changes and mild depression
High cholesterol
Vaginal dryness
Serious side effects requiring immediate medical attention:
Bone loss (osteopenia, osteoporosis, fractures) — requires DEXA scan monitoring
Severe allergic reactions (anaphylaxis, angioedema)
Liver damage (hepatotoxicity)
Cardiovascular events (decreased coronary blood flow)
Stroke symptoms
Severe skin reactions (Stevens-Johnson syndrome)
Know what you need? Skip the search.
Letrozole (Femara)
Non-steroidal aromatase inhibitor; 2.5 mg once daily. Similar mechanism and indications. Most commonly substituted for anastrozole; no washout required when switching.
Exemestane (Aromasin)
Steroidal aromatase inactivator; 25 mg once daily with food. Permanently inactivates aromatase (irreversible). Similar efficacy with slightly different side effect profile.
Tamoxifen (Nolvadex)
Selective estrogen receptor modulator (SERM); 20 mg once daily. Works differently — blocks estrogen receptors rather than reducing estrogen production. Appropriate for pre- and postmenopausal women; cannot be used concurrently with anastrozole.
Fulvestrant (Faslodex)
Estrogen receptor degrader; monthly injection. Used for advanced/metastatic HR-positive breast cancer, typically after aromatase inhibitor failure. Not a direct substitute for anastrozole in early-stage settings.
Prefer Anastrozole? We can find it.
Tamoxifen
majorTamoxifen reduces anastrozole plasma levels by approximately 27% via an unspecified mechanism, significantly reducing its effectiveness. The combination is contraindicated — these drugs should never be used together.
Estrogens (HRT, birth control, vaginal estrogen)
majorPharmacodynamic antagonism — estrogen products directly counteract anastrozole's mechanism of action by replacing the estrogen anastrozole is trying to suppress. All estrogen-containing products are contraindicated during anastrozole therapy.
Warfarin
moderateAnastrozole does not significantly alter warfarin's anticoagulant effects in clinical studies, but individual variability warrants INR monitoring when starting or stopping anastrozole.
St. John's Wort
moderateCYP3A4 inducer that may reduce anastrozole plasma levels, potentially reducing its effectiveness. Avoid concurrent use.
CYP3A4 substrates
minorAnastrozole is a mild inhibitor of CYP3A4 and other CYP enzymes. At the 1 mg therapeutic dose, clinically significant interactions are unlikely but theoretically possible with certain narrow-therapeutic-index drugs.
Anastrozole is one of the most effective and affordable treatments available for hormone receptor-positive breast cancer in postmenopausal women. With a well-established track record from the landmark ATAC trial and many years of real-world use, it remains a first-line standard of care. Generic anastrozole is widely available and dramatically less expensive than brand-name Arimidex — as little as $5–$15 per month with the right discount coupon.
The most important thing for patients to understand is the value of consistent, uninterrupted therapy. Joint pain and hot flashes may be uncomfortable, but stopping anastrozole early significantly increases breast cancer recurrence risk. Work closely with your oncologist to manage side effects rather than discontinuing treatment.
If you ever have trouble finding anastrozole at your pharmacy, medfinder can call pharmacies near you to find which ones have it in stock — helping you maintain treatment continuity without the frustration of calling around yourself.
Medfinder Editorial Standards
Our medication guides are researched and written to help patients make informed decisions. All content is reviewed for accuracy and updated regularly. Learn more about our standards
ChatGPT
Claude
Perplexity
Grok
Gemini