Comprehensive medication guide to Letrozole 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 Letrozole on most commercial plans (Tier 1–2); Medicare Part D covers generic Letrozole with a $2,100 annual out-of-pocket cap in 2026; prior authorization may be required for some plans.
Estimated Cash Pricing
$12–$15 with GoodRx or SingleCare coupons for a 30-day supply of generic Letrozole 2.5 mg; retail price without a coupon ranges from $135–$341+ per 30 tablets depending on pharmacy.
Medfinder Findability Score
82/100
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Letrozole is a prescription oral medication belonging to the class of drugs called nonsteroidal aromatase inhibitors (AIs). It is sold under the brand name Femara (manufactured by Novartis), and is widely available as a generic from multiple manufacturers. Letrozole comes as a 2.5 mg tablet taken once daily.
Letrozole is FDA-approved for treating hormone receptor-positive breast cancer in postmenopausal women — including adjuvant therapy after surgery, extended adjuvant therapy following 5 years of tamoxifen, and first- or second-line treatment of locally advanced or metastatic breast cancer. It is also widely prescribed off-label for ovulation induction in women with polycystic ovary syndrome (PCOS), where it has become the preferred first-line fertility agent per ACOG guidelines.
Letrozole is not chemotherapy. It is hormone therapy (endocrine therapy) that works by suppressing estrogen to stop hormone-sensitive cancer cells from growing, or — in fertility use — by temporarily lowering estrogen to stimulate ovulation.
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Letrozole works by competitively binding to and inhibiting the aromatase enzyme — specifically at the heme group of the enzyme's cytochrome P450 component. Aromatase is responsible for converting androgens (male hormones like testosterone) into estrogens (estrone and estradiol) in peripheral tissues such as fat, muscle, and skin. By blocking aromatase, Letrozole reduces estrogen levels by more than 99% in postmenopausal women.
For hormone receptor-positive breast cancer, this matters because cancer cells with estrogen receptors need estrogen to grow. By removing estrogen, Letrozole deprives cancer cells of their growth signal — slowing, stopping, or reversing tumor growth. For fertility treatment, Letrozole temporarily suppresses estrogen, triggering the pituitary gland to release more FSH (follicle-stimulating hormone), which stimulates ovarian follicle development and ovulation.
Letrozole is highly selective for aromatase and does not impair adrenal steroidogenesis — it does not affect production of cortisol, aldosterone, or other adrenal hormones, so no supplemental steroids are needed during treatment.
2.5 mg — tablet
Standard dose for all approved indications; taken once daily with or without food
As of 2026, Letrozole is not on the FDA's national drug shortage list. Multiple generic manufacturers produce Letrozole 2.5 mg tablets, providing meaningful supply resilience. However, patients do sometimes encounter availability gaps at their local pharmacy due to periodic manufacturer lot recalls, distributor delays, and local pharmacy ordering patterns.
Availability tends to be better at high-volume chain pharmacies (CVS, Walgreens, Walmart, Costco) and grocery store pharmacies than at smaller independent locations. Patients on long-term breast cancer therapy are strongly advised to use mail-order pharmacy for 90-day supplies to avoid local availability issues. Fertility patients should confirm pharmacy stock at least one week before their expected cycle start date.
If your pharmacy is out of Letrozole, medfinder calls pharmacies near you on your behalf to find which ones can fill your prescription — and texts you the results. No hold music. No phone tag.
Letrozole is not a controlled substance, so any licensed physician, nurse practitioner (NP), or physician assistant (PA) with prescribing authority can write a prescription. In practice, it is most commonly prescribed by specialists with expertise in the relevant condition:
Medical oncologists — primary prescribers for breast cancer adjuvant and metastatic therapy
Gynecologic oncologists — for breast and gynecologic cancers with hormone-sensitive components
Reproductive endocrinologists (REI) — for fertility and PCOS ovulation induction; the gold standard for fertility prescriptions
OB-GYNs — commonly prescribe Letrozole for PCOS ovulation induction; ACOG endorses its off-label use
Primary care providers (PCPs) — may manage refills for established breast cancer patients on stable long-term therapy under oncologist oversight
NPs and PAs — commonly prescribe within oncology and fertility practices
Telehealth availability: Since Letrozole is not a controlled substance, it can be prescribed via telehealth in most states — a convenient option for breast cancer patients on stable long-term therapy or for patients in rural areas seeking fertility treatment without easy access to a specialist.
No. Letrozole is not classified as a controlled substance by the U.S. Drug Enforcement Administration (DEA). It is not assigned to any DEA schedule (I through V). This means:
Prescriptions can be written with standard prescription forms — no special DEA-controlled substance forms are required
Prescriptions can be transferred between pharmacies without restriction
Letrozole can be prescribed via telehealth in most states
Refills can be written on the original prescription (up to the limits set by your doctor)
Because Letrozole suppresses estrogen by more than 99%, many side effects resemble intensified menopause symptoms. Common side effects include:
Hot flashes and night sweats
Joint and muscle pain (arthralgia/myalgia)
Bone loss (osteopenia/osteoporosis) with long-term use
Fatigue and decreased energy
Nausea (mild, typically in early weeks)
Hair thinning (diffuse, not complete hair loss)
Elevated cholesterol
Headache and dizziness
Bone fractures from minimal trauma (sign of severe bone density loss)
Blood clots (DVT or pulmonary embolism) — leg swelling, chest pain, shortness of breath
Liver dysfunction — jaundice, dark urine, severe abdominal pain
Cardiovascular events — chest pain, signs of heart attack or stroke
Severe allergic reaction — hives, throat swelling, difficulty breathing (call 911)
Fetal harm — Letrozole is contraindicated in pregnancy and can cause birth defects or miscarriage
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Anastrozole (Arimidex)
Nonsteroidal aromatase inhibitor with the same mechanism as letrozole; clinical trials show equivalent efficacy for breast cancer; dosed at 1 mg once daily; widely available generic
Exemestane (Aromasin)
Steroidal aromatase inhibitor that irreversibly inactivates aromatase; slightly different side effect profile; dosed at 25 mg daily with food; available as generic
Tamoxifen (Nolvadex)
Selective estrogen receptor modulator (SERM); preferred for premenopausal women; blocks estrogen receptors rather than suppressing estrogen production; taken for 5-10 years; inexpensive generic widely available
Fulvestrant (Faslodex)
Selective estrogen receptor degrader (SERD); monthly injection; used primarily in advanced or metastatic HR+ breast cancer; not typically used as a direct substitute for letrozole in adjuvant therapy
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Estrogen-containing medications (HRT, oral contraceptives)
majorDirectly counteract letrozole's mechanism of action by adding estrogen back to the system; significantly reduce treatment effectiveness for breast cancer; avoid concurrent use
Tamoxifen (concurrent use)
moderateConcurrent administration reduces letrozole plasma levels; these drugs should be used sequentially, not simultaneously; your oncologist manages the sequencing
St. John's Wort
moderateCYP3A4 inducer that may reduce letrozole blood levels; avoid during letrozole therapy
DHEA supplements
moderateAn androgen precursor that converts to estrogen in the body; may counteract letrozole's estrogen-suppressing effects; avoid during breast cancer therapy
Warfarin
minorNo clinically significant interaction found in dedicated interaction study; standard monitoring applies when starting any new medication
Letrozole (Femara) is a cornerstone medication for two major populations: postmenopausal women with hormone receptor-positive breast cancer, and women with PCOS seeking fertility treatment. In both cases, it is highly effective, widely prescribed, and — in generic form — among the most affordable medications in its class.
While Letrozole is not in a national shortage as of 2026, patients do sometimes encounter local availability gaps at their pharmacy. The most effective strategies to stay ahead of these issues are: refill proactively (at least 7-10 days before running out), use mail-order pharmacy for 90-day supplies when taking it long-term, and have backup pharmacy options identified in advance.
If your pharmacy is ever out of Letrozole, medfinder can help. We call pharmacies near you to find which ones can fill your prescription, then text you the results — so you spend less time on hold and more time focused on your health.
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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
Real-time availability
Medfinder is actively checking pharmacy inventory for Letrozole. We don't publish a number until we have enough verified pharmacy checks to be accurate — start a search and our team confirms current availability near you, usually within 24 hours.
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