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Tamoxifen

Tamoxifen is a hormone-blocking therapy used to treat breast cancer, reduce the risk of invasive breast cancer in high-risk women, and lower the chance of breast cancer recurrence after surgery.

Brand names NolvadexSoltamox
Drug class Estrogen Agonist/antagonist
Rx Forms 2
Dr. Brian Staiger, PharmD, BCPS
Reviewed by Last reviewed Jul 10, 2026 Content updated Oct 2, 2026
🧬 Where this information comes from Click to expand

The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 15 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →

✓No current FDA shortage listed · checked Oct 6, 2026
Tamoxifen at a glance The quick version — the full detail is in the Patient Information Guide below.
Dr. Brian Staiger, PharmD, BCPS
The Pharmacist’s Take By · Clinical pharmacist · Written

Tamoxifen, used since the late 1970s and available as a generic, is a standard hormone therapy that treats breast cancer, helps keep it from coming back and lowers risk in high-risk women by blocking estrogen in breast tissue while acting mildly like estrogen elsewhere, such as the uterus. Most people manage it well, and hot flashes are what they notice most, along with vaginal discharge or dryness. Its boxed warning covers uterine cancer, stroke and blood clots in the lungs, so report abnormal vaginal bleeding promptly and get emergency help for sudden leg swelling, chest pain or breathlessness. For most people already diagnosed, the benefit clearly outweighs these risks.

Clinical pearls

  • Paroxetine and some other antidepressants can blunt how well tamoxifen works, so get any new antidepressant checked for interactions.
  • If you take warfarin, expect closer blood monitoring, since tamoxifen can sharply strengthen its blood-thinning effect.
  • Use non-hormonal birth control during treatment and for two months after stopping, because tamoxifen can seriously harm a fetus.
  • Book a gynecologic exam every year, and mention any vision changes, since cataracts have been reported with tamoxifen.
How we write & review this content — our editorial policy →
⚠️ FDA Boxed Warning — the FDA’s strongest safety alert ▾

Tamoxifen can cause serious, life-threatening conditions including uterine cancer, stroke, and pulmonary embolism (blood clots in the lungs) — and fatal cases of each have occurred. The risk of uterine cancer (endometrial adenocarcinoma and uterine sarcoma) is higher in women taking tamoxifen than in those who do not. The risk of blood clots in the lungs and stroke is also increased. These risks are most important to weigh carefully for women who are considering tamoxifen only to reduce their breast cancer risk (high-risk women) or to reduce the risk of invasive breast cancer after DCIS — your doctor should walk through the benefits and risks with you individually. For women already diagnosed with breast cancer, the benefits of tamoxifen generally outweigh these risks. Watch for signs of these serious events: abnormal vaginal bleeding, sudden shortness of breath, chest pain, leg swelling or pain, and sudden weakness or difficulty speaking.

Read the full warning on DailyMed →
How you get itPrescription only
Comes asTablet, Oral solution
Earliest FDA record1977
Companies listing it with the FDA10
FDA label last updatedNov 29, 2021
FDA’s strongest warning (boxed)Yes, read the warning

Patient information guide A plain-language walkthrough of Tamoxifen, written from its FDA label.

What Tamoxifen is used for

▾

Tamoxifen is approved for several breast-cancer-related uses across its available products.

  • Metastatic breast cancer: Treats estrogen receptor-positive breast cancer that has spread, in both women and men. In premenopausal women, it is an alternative to surgical or radiation removal of the ovaries.
  • Adjuvant treatment of breast cancer: Used after surgery (with or without radiation) to reduce recurrence in women with node-positive or node-negative early-stage breast cancer. Also reduces the chance of cancer developing in the opposite breast.
  • Ductal carcinoma in situ (DCIS): Reduces the risk of invasive breast cancer in women who have had breast surgery and radiation for DCIS. Soltamox and Tamoxifen Citrate tablets are both indicated for this use.
  • Reduction in breast cancer incidence in high-risk women: Reduces the chance of developing breast cancer in women who have not yet been diagnosed but are at high risk based on age, family history, biopsy history, and other factors. Both Soltamox and Tamoxifen Citrate tablets are indicated for this use.

How Tamoxifen works

▾

Tamoxifen is an estrogen agonist/antagonist — it competes with estrogen for binding sites on estrogen receptors, particularly in breast tissue. By occupying these receptors, it blocks estrogen from attaching and signaling cells to grow. This slows or stops the growth of estrogen-driven breast cancer cells. It has been shown to cause regression of established breast tumors in laboratory models.

Tamoxifen is extensively converted in the body to active metabolites — particularly endoxifen and 4-hydroxytamoxifen — which bind estrogen receptors with much greater potency than tamoxifen itself. The enzyme CYP2D6 plays a key role in producing these metabolites, which is why certain medications that inhibit CYP2D6 may affect how well tamoxifen works.

Tamoxifen dosage

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Tamoxifen is taken by mouth, typically once daily, though higher doses may be split into a morning and an evening dose. Soltamox oral solution can be taken with or without food. Tamoxifen Citrate tablets are also taken orally on a schedule set by your prescriber. Treatment usually continues for 5 years, and in the adjuvant breast cancer setting, Soltamox may be used for 5 to 10 years. Always follow your prescriber's specific instructions — do not stop early or change your dose without guidance.

Dosing details from the FDA-approved label

From the Tamoxifen prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.

  • Breast cancer (metastatic breast cancer)
    • Recommended daily dose is 20 to 40 mg
    • Dosages greater than 20 mg per day should be given in divided doses (morning and evening)
  • Adjuvant treatment of breast cancer
    • Tablets: current data support 5 years of adjuvant therapy
    • Studies used one 10 mg tablet two or three times a day for two years, or one 10 mg tablet twice a day for at least 5 years
    • Soltamox: 20 mg daily for 5-10 years
    • Maximum: Doses greater than 20 mg daily yield no additional clinical benefit (Soltamox).
  • Ductal Carcinoma in Situ (DCIS)
    • 20 mg daily for 5 years
  • Reduction in Breast Cancer Incidence in High Risk Women
    • 20 mg daily for 5 years
    • There are no data to support use of tamoxifen other than for 5 years.
Read the label’s full dosing text

DOSAGE AND ADMINISTRATION For patients with breast cancer, the recommended daily dose is 20 to 40 mg. Dosages greater than 20 mg per day should be given in divided doses (morning and evening). In three single agent adjuvant studies in women, one 10 mg tamoxifen citrate tablet was administered two (ECOG and NATO) or three (Toronto) times a day for two years. In the NSABP B-14 adjuvant study in women with node-negative breast cancer, one 10 mg tamoxifen citrate tablet was given twice a day for at least 5 years. Results of the B-14 study suggest that continuation of therapy beyond five years does not provide additional benefit (see CLINICAL PHARMACOLOGY ). In the EBCTCG 1995 overview, the reduction in recurrence and mortality was greater in those studies that used tamoxifen for about 5 years than in those that used tamoxifen for a shorter period of therapy. There was no indication that doses greater than 20 mg per day were more effective. Current data from clinical trials support 5 years of adjuvant tamoxifen therapy for patients with breast cancer. Ductal Carcinoma in Situ (DCIS): The recommended dose is tamoxifen citrate tablets 20 mg daily for 5 years. Reduction in Breast Cancer Incidence in High Risk Women: The recommended dose is tamoxifen citrate tablets 20 mg daily for 5 years. There are no data to support the use of tamoxifen other than for 5 years (see CLINICAL PHARMACOLOGY, Clinical Studies , Reduction in Breast Cancer Incidence in High Risk Women ).

Read the full Dosage and Administration section on DailyMed →

Tamoxifen side effects

▾

The most commonly reported side effects include:

Common side effects

  • Hot flashes
  • Vaginal discharge or vaginal dryness
  • Irregular menstrual periods or stopped periods
  • Nausea
  • Mood changes or depression
  • Swelling (peripheral edema)
  • Headache or dizziness
  • Skin changes or rash
  • Irregular or absent menstrual periods
  • Mood changes, depression, or anxiety
  • Swelling in the hands or feet (peripheral edema)
  • Hair thinning or partial hair loss

When to get medical help

  • Call your doctor right away if you have abnormal vaginal bleeding — this can be a sign of uterine cancer
  • Seek emergency help immediately for signs of a blood clot: sudden leg pain or swelling, chest pain, shortness of breath, or coughing up blood
  • Call 911 for signs of stroke: sudden face drooping, arm weakness, or speech difficulty
  • Report any visual changes or eye problems to your doctor promptly
  • Tell your doctor if you notice yellowing of the skin or eyes, dark urine, or severe fatigue — these may signal liver problems
  • Contact your doctor if you develop unusual bruising or bleeding, which could indicate low platelet counts

Seek medical attention right away for serious signs: abnormal vaginal bleeding, sudden shortness of breath or chest pain, leg pain or swelling, sudden weakness, difficulty speaking, or visual changes — these could signal uterine cancer, a blood clot, stroke, or liver problems.

Tamoxifen warnings and precautions

▾
  • Uterine cancer: Tamoxifen increases the risk of uterine cancers (endometrial adenocarcinoma and uterine sarcoma), with fatal cases reported. Long-term use (2+ years) carries higher risk. Report any abnormal vaginal bleeding immediately. Annual gynecological exams are recommended.
  • Blood clots and stroke: Risk of deep vein thrombosis, pulmonary embolism, and stroke is increased — especially in women over 50 and when combined with chemotherapy. Seek emergency care for any signs of clotting or stroke.
  • Liver problems: Liver cancer and serious non-cancerous liver conditions (including hepatitis and liver necrosis) have been reported, with some fatal cases. Periodic liver function tests are recommended.
  • Fetal harm: Tamoxifen can cause serious harm to a developing baby, including birth defects and fetal death. Effective non-hormonal contraception is required during treatment and for 2 months after stopping.
  • Eye changes: Increased risk of cataracts and cataract surgery, plus other eye changes including retinal problems. Report any vision changes promptly.
  • Low blood counts: Decreases in platelets and white blood cells have been reported. Periodic blood count monitoring is recommended.
  • High calcium: In patients with bone metastases, tamoxifen may cause hypercalcemia (high blood calcium) shortly after starting treatment.

Tamoxifen interactions

▾

Tamoxifen has several important drug interactions that can affect its safety or effectiveness:

  • Warfarin: Tamoxifen markedly increases warfarin's blood-thinning effect — close monitoring is essential, and use with warfarin is contraindicated when taking tamoxifen for DCIS or risk reduction.
  • Anastrozole: Should not be combined with tamoxifen — the combination offers no added benefit and tamoxifen reduces anastrozole blood levels by 27%.
  • Letrozole: Not recommended in combination — tamoxifen reduces letrozole blood levels by 38%.
  • Rifampin and strong CYP3A4 inducers: Dramatically reduce tamoxifen levels in the blood — should be avoided.
  • Strong CYP2D6 inhibitors (e.g., paroxetine and certain other antidepressants): May reduce levels of tamoxifen's most potent active metabolite (endoxifen), potentially reducing effectiveness — discuss alternatives with your prescriber.
  • Chemotherapy: Combined use further increases risk of blood clots.

Interactions listed in the FDA-approved label

From the Tamoxifen prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.

  • Anastrozole: The combination did not demonstrate any benefit compared to tamoxifen alone; coadministration reduced the anastrozole plasma concentration by 27% and did not alter the tamoxifen concentration. Should be avoided in all patients.
  • Letrozole: Tamoxifen reduced the plasma concentration of letrozole by 38% when co-administered; efficacy of the combination in adjuvant treatment of breast cancer has not been established. Concomitant use is not recommended.
  • Warfarin: A marked increase in anticoagulant effect may occur when tamoxifen is used with warfarin. Closely monitor coagulation indices in patients taking tamoxifen for metastatic breast cancer or as adjuvant therapy who require warfarin. Do not use in patients taking tamoxifen for DCIS or for reduction in breast cancer incidence in women at high risk.
  • Strong CYP3A4 inducers (e.g., rifampin): Strong CYP3A4 inducers reduce tamoxifen AUC and Cmax. Strong CYP3A4 inducers should not be used with tamoxifen.
  • Strong CYP2D6 inhibitors (e.g., paroxetine): Impact on tamoxifen efficacy is not well established; some studies showed efficacy may be reduced due to reduced levels of potent active metabolites, while other studies failed to demonstrate such an effect.
  • Laboratory tests (thyroid and vaginal/Pap smears): Postmarketing reports of T4 elevations in postmenopausal patients, possibly from increased thyroid-binding globulin, without clinical hyperthyroidism; variations in karyopyknotic index on vaginal smears and various degrees of estrogen effect on Pap smears have been seen in postmenopausal patients.
Read the label’s full interactions text

7 DRUG INTERACTIONS Anastrozole and letrozole: Should not be used in combination with tamoxifen. ( 7.1 ) Warfarin: Do not use in patients taking tamoxifen for DCIS and for reduction in breast cancer incidence in women at high risk. ( 4 ) Closely monitor coagulation indices for increased anticoagulant effect when used with tamoxifen for metastatic breast cancer or as adjuvant therapy. ( 7.2 ) 7.1 Aromatase Inhibitors Anastrozole The combination of anastrozole and tamoxifen did not demonstrate any benefit when compared to tamoxifen alone and should be avoided in all patients [see Clinical Studies (14.2) ] . In the ATAC trial, coadministration of anastrozole and tamoxifen in breast cancer patients reduced the anastrozole plasma concentration by 27% compared to that achieved with anastrozole alone. The tamoxifen concentration was not altered [see Clinical Pharmacology (12.3) ]. Letrozole The concomitant use of letrozole with tamoxifen is not recommended because the efficacy of the combination in the adjuvant treatment of breast cancer has not been established. Tamoxifen reduced the plasma concentration of letrozole by 38% when these drugs were co-administered [see Clinical Pharmacology (12.3) ]. 7.2. Warfarin A marked increase in anticoagulant effect may occur when tamoxifen is used in combination with warfarin. Closely monitor coagulation indices in patients who are taking tamoxifen for either the treatment of metastatic breast cancer or as adjuvant therapy who require concomitant use of warfarin [see Contraindications (4) ] . 7.3 Inducers of CYP3A4 Strong CYP3A4 inducers should not be used with tamoxifen. Strong CYP3A4 inducers (e.g., rifampin) reduce tamoxifen AUC and C max [see Clinical Pharmacology (12.3) ] . 7.4 Strong Inhibitors of CYP2D6 The impact on the efficacy of tamoxifen with co-administration of strong CYP2D6 inhibitors (e.g., paroxetine) is not well established.

Excerpted — the section continues on the label. Read the full Drug Interactions section on DailyMed →

Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.

🌿210 supplements and herbs with documented Tamoxifen interactions, ranked by severity Check Tamoxifen against a supplement or herb →

Before taking Tamoxifen

▾
  • Tell your doctor if you have ever had a blood clot in the legs or lungs — this is a contraindication for using tamoxifen to reduce breast cancer risk or treat DCIS.
  • Tell your doctor if you take warfarin or any blood thinner — warfarin use is a contraindication for certain tamoxifen indications.
  • Tell your doctor if you are allergic to tamoxifen or any ingredient in Soltamox (including the oral solution base).
  • Do not start tamoxifen if you are pregnant — a negative pregnancy test must be confirmed first. Use effective non-hormonal contraception during treatment and for 2 months after the last dose.
  • Do not breastfeed during treatment or for 3 months after the last dose — tamoxifen may harm a nursing infant and also inhibits milk production.
  • Be aware that tamoxifen does not reliably prevent pregnancy, even if your periods become irregular — contraception is still needed.
  • Tell your doctor about all other medications, especially antidepressants that inhibit CYP2D6.
  • Safety and effectiveness in children have not been established for breast cancer uses; limited data exist for McCune-Albright syndrome in girls aged 2–10, but long-term effects are not known.
  • Older women (especially those 50 and over) face a higher absolute risk of serious events like stroke and pulmonary embolism.
  • Liver function and blood counts should be monitored regularly during treatment.

Tamoxifen overdose

▾

Taking too much tamoxifen can cause tremors, unsteady walking, exaggerated reflexes, and dizziness. At very high doses, changes in heart rhythm (QT interval prolongation on an electrocardiogram) have also been observed. There is no specific antidote — treatment is supportive and symptom-based. If you suspect an overdose, seek medical attention right away.

What Tamoxifen does in the body

▾

Tamoxifen blocks estrogen from binding to its receptors in breast tissue, reducing estrogen-driven cell growth. It has also demonstrated the ability to cause regression of established estrogen-receptor-positive breast tumors in laboratory models. While it acts as an estrogen blocker in breast tissue, it has partial estrogen-like (agonist) effects in the uterus and on bone — which explains some of its risks (uterine changes) and benefits (bone mineral density preservation) seen in clinical studies.

How your body processes Tamoxifen

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After an oral dose, tamoxifen is absorbed and reaches peak blood levels in about 5 hours, with a half-life of roughly 5 to 7 days. It is extensively broken down by liver enzymes (including CYP3A, CYP2D6, CYP2C9, and others) into several metabolites — the most important being endoxifen and 4-hydroxytamoxifen, which are far more potent than tamoxifen itself at blocking estrogen receptors. Steady-state levels build up over about 4 weeks for tamoxifen and about 8 weeks for its main metabolite. The drug is eliminated primarily through the feces. Soltamox oral solution is bioequivalent to tamoxifen citrate tablets and can be taken with or without food without affecting absorption.

How to store Tamoxifen

▾

Store at room temperatures 20° to 25°C (68° - 77°F); excursions permitted between 15° to 30°C (59° - 86°F) . DO NOT freeze or refrigerate. Store in original packaging in order to protect from light.

Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →

210

Supplements & herbs that interact with Tamoxifen

210 supplements and herbal products have documented interactions with Tamoxifen in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.

Severity mix
  • Major · 11
  • Moderate · 166
  • Minor · 33
ACTIVATED CHARCOAL Major AMERICAN HELLEBORE Major ARSENIC Major BEER Major CESIUM Major EPHEDRA Major GRAPEFRUIT Major SIBERIAN COCKLEBUR Major +202 more
Every supplement checked against Tamoxifen — ranked by severity The full interaction hub: 11 major · 166 moderate · 33 minor · every one linked to its full report. Check Tamoxifen against your exact supplements

Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.

Tamoxifen: pharmacist answers to common questions

Quick, plain-English answers to the questions patients ask most about Tamoxifen — the kind of thing our pharmacy team would talk through with you at the counter.

What exactly is tamoxifen supposed to do for me?

▾
Tamoxifen works by blocking estrogen from fueling breast cancer cells — think of it as putting a lock on the door that estrogen uses to make cancer grow. Depending on your situation, it might be treating active breast cancer, preventing your cancer from coming back after surgery, or lowering your risk of developing breast cancer in the first place. Your doctor chose it because your cancer or risk is driven by estrogen, and tamoxifen is one of the most proven tools we have for that.

How long do I have to take tamoxifen?

▾
For most breast cancer uses — including after surgery and for DCIS or high-risk reduction — treatment is typically 5 years. In some adjuvant situations, Soltamox may be used for up to 10 years. The length of time really matters for how well it works, so try not to stop early without talking to your doctor first. It can feel like a long commitment, but the protection it offers is real.

What side effects should I actually expect versus what I should call my doctor about?

▾
Hot flashes and vaginal changes (dryness, discharge, or irregular periods) are the most common things people notice — they're uncomfortable but generally manageable. Nausea, mood changes, and mild swelling also happen. What you should call your doctor about right away: any unusual vaginal bleeding, leg pain or swelling, sudden shortness of breath, chest pain, or any change in vision. These could point to something serious like a blood clot, stroke, or a uterine problem — and those need prompt attention.

Can I get pregnant while taking tamoxifen?

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You should not get pregnant while taking tamoxifen — it can seriously harm a developing baby, including causing birth defects or pregnancy loss. Even if your periods become irregular, tamoxifen does not reliably prevent pregnancy, so you need to use effective non-hormonal contraception (not hormonal birth control) throughout treatment and for 2 months after your last dose. Before starting, your doctor should confirm with a pregnancy test that you are not pregnant.

Are there medications I need to avoid while on tamoxifen?

▾
Yes, a few important ones. If you take warfarin (a blood thinner), tamoxifen can dramatically increase its effect — your doctor will need to monitor you closely, or the combination may not be appropriate for you at all. Certain antidepressants (particularly paroxetine) can reduce how well tamoxifen works by blocking the enzyme that converts it to its most active form — talk to your doctor or pharmacist about safer alternatives. Also, tamoxifen should not be combined with aromatase inhibitors like anastrozole or letrozole.

Should I be worried about uterine cancer from tamoxifen?

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It's a real risk worth knowing about, not one to panic over. Tamoxifen does increase the chance of uterine cancer — but most cases, when caught early because of symptoms, are highly treatable. The single most important thing you can do is report any abnormal vaginal bleeding to your doctor right away, even if it seems minor. Annual gynecological exams are also recommended while you're on tamoxifen. For women already diagnosed with breast cancer, the benefits of tamoxifen still outweigh this risk for most people — your doctor would have weighed this carefully before prescribing it.

Is Tamoxifen available over the counter?

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No. Tamoxifen is a prescription medicine: every Tamoxifen product listed with the FDA is prescription only, so it is not sold over the counter. Your prescriber decides whether it is appropriate for you, and your pharmacist dispenses it.

When was Tamoxifen first available?

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The earliest FDA record we hold for Tamoxifen is from 1977: its first approval in Drugs@FDA or its earliest product listing in the NDC Directory, whichever is older. Many older medicines were in use before their first formal FDA approval, so this is the earliest date on record, not necessarily when Tamoxifen was first used.

Who makes Tamoxifen?

▾
10 companies currently list Tamoxifen products in the FDA's NDC Directory, including Bryant Ranch Prepack, A-S Medication Solutions, Actavis Pharma, Inc.. That count includes repackagers and distributors as well as manufacturers (companies that sell only the raw ingredient are not counted), so fewer companies actually make it; the label on your bottle names the one that supplied yours.

Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →

More about Tamoxifen on HelloPharmacist

📊Tamoxifen supplement interactions210 checked — ranked by severity 🌿Drug & Supplement CheckerTamoxifen vs. vitamins & herbs 💬Ask a PharmacistFree answer, usually < 24h 🔎NDC & pricing lookupFind Tamoxifen NDCs & costs 🅰️Browse Drugs A–ZLook up any medication
Detailed data & references for Tamoxifen Forms & strengths, pricing, billing codes, manufacturers, safety reports and sourcing — the data behind the page. Most people can stop here. Each section below opens on a tap.

Tamoxifen forms and strengths (how it comes)

Tamoxifen is available in 2 forms. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.

Need a version that does not list lactose, a gluten source, a dye or gelatin? Inactive ingredients differ by manufacturer: see Tamoxifen inactive ingredients by manufacturer.

Tablet

By mouth
How this form is used
What it may be used for
  • Tamoxifen Citrate tablets are used to treat metastatic breast cancer in women and men
  • Tamoxifen Citrate tablets are used as adjuvant treatment for node-positive and axillary node-negative breast cancer in women after surgery
  • Tamoxifen Citrate tablets are used in women with DCIS after breast surgery and radiation to reduce the risk of invasive breast cancer
  • Tamoxifen Citrate tablets are used to reduce the incidence of breast cancer in women at high risk
Important instructions
  • Tamoxifen Citrate tablets are taken by mouth, once or twice daily depending on the prescribed regimen
  • For breast cancer treatment, higher daily doses are split into a morning and evening dose
  • Current clinical data support taking Tamoxifen Citrate tablets for approximately 5 years for breast cancer; follow your prescriber's guidance on duration
  • For DCIS and risk reduction, Tamoxifen Citrate tablets are taken once daily for 5 years as directed
Available strengths 2 strengths
10 mg 20 mg
34 FDA-listed product records ⓘ

Oral solution

By mouth
Brands Soltamox
How this form is used
What it may be used for
  • Soltamox is indicated for the treatment of estrogen receptor-positive metastatic breast cancer in adults
  • Soltamox is indicated as adjuvant treatment for early-stage estrogen receptor-positive breast cancer in adults, including reducing occurrence of cancer in the opposite breast
  • Soltamox is indicated to reduce the risk of invasive breast cancer in women with DCIS following breast surgery and radiation
  • Soltamox is indicated to reduce the incidence of breast cancer in adult women at high risk
Important instructions
  • Soltamox can be taken with or without food — there is no difference in absorption either way
  • Soltamox is taken by mouth once or twice daily depending on the condition being treated — follow your prescriber's instructions
  • Soltamox is typically taken for 5 years for DCIS and risk reduction; adjuvant use may continue for 5–10 years as directed
  • For Soltamox doses greater than the standard daily amount, the dose is split between morning and evening
Available strengths 1 strength
20 mg/10 mL
1 FDA-listed product record ⓘ

Tamoxifen on the U.S. market: products, makers and brands

How Tamoxifen appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.

10 companies list 18 Tamoxifen product records with the FDA, mostly as tablet, oral solution; the earliest marketing or approval year on record is 1977. Brand names on the directory include Nolvadex, Soltamox; the rest are generics.

2
Dose forms ⓘ
10
Labelers (makers, repackagers, distributors)
2
Brand names
18
FDA-listed product records ⓘ
1977
Earliest FDA record ⓘ

FDA-listed product records by dose form (tablet variants merged) — FDA National Drug Code Directory. Record counts are not sales or prescription volume.

Also listed with the FDA, not a patient dose form: Powder (15) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.

Bryant Ranch Prepack17%
A-S Medication Solutions11%
Actavis Pharma, Inc.11%
Aurobindo Pharma Limited11%
Dr. Reddy's Labratories Inc.11%
Mylan Pharmaceuticals Inc.11%
Other makers28%

Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.

How widely Tamoxifen is used (Medicaid data)

A general measure of how commonly Tamoxifen is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.

Think of this as a proxy for how widely Tamoxifen is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.

103,836
Medicaid prescriptions filled (Q1–Q4 2025)
$2.1M gross Medicaid reimbursement (before mandatory rebates — net cost is lower)

How commonly is Tamoxifen prescribed? Of the 1,601 medications we measure, Tamoxifen ranks #505 by Medicaid prescriptions — more than 68% of them.

Where Tamoxifen ranks among the drugs we measure · Q1–Q4 2025 · neighbors ±5
Total prescriptions — #505 of 1,601
#500 Alogliptin 105,424 Rx #501 Buprenorphine Transder... 105,289 Rx #502 Telmisartan 104,917 Rx #503 Daptomycin Injection 104,494 Rx #504 Daptomycin 104,494 Rx #505 Tamoxifen 103,836 Rx #506 Leflunomide 103,763 Rx #507 Dolutegravir and Lamiv... 103,012 Rx #508 Trihexyphenidyl 102,119 Rx #509 Primidone 102,071 Rx #510 Infliximab Injection 101,484 Rx

Utilization by Tamoxifen product

Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.

The 20 mg oral tablet is the most-dispensed Tamoxifen product — about 90% of these Medicaid prescriptions.

tamoxifen 20 MG Oral Tablet Most dispensed

93,446 Medicaid prescriptions (Q1–Q4 2025) 90% of Tamoxifen prescriptions shown $1.9M gross reimbursement (before rebates) ≈ $21 per prescription (gross)

Summed across the 9 of 45 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 313195

tamoxifen 10 MG Oral Tablet

10,390 Medicaid prescriptions (Q1–Q4 2025) 10% of Tamoxifen prescriptions shown $141,093 gross reimbursement (before rebates) ≈ $14 per prescription (gross)

Summed across the 5 of 26 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 198240

Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.

Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Tamoxifen, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 14 of 71 listed Tamoxifen NDCs with Medicaid activity.

Compare Tamoxifen products

A representative set of FDA-listed product records for Tamoxifen — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)

Showing 18 of 18 products — FDA National Drug Code Directory. See every product, package size and price: browse all 18 Tamoxifen NDCs →

Tamoxifen side effects reported to the FDA (FAERS)

After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Tamoxifen — a signal of what to watch for, not proof the drug caused it.

The effects most often named in FDA reports that mention Tamoxifen are fatigue, nausea, diarrhoea; about 77% of the reports were classed as serious. These are voluntary reports, so they show what people report, not how often it happens.

5,726
Reports mentioning it
77%
Reported as serious
12
Distinct effects shown
Most reported effects
Fatigue
395
Nausea
350
Diarrhoea
278
Arthralgia
276
Malignant Neoplasm Progression
266
Pain
247
Vomiting
229
Dyspnoea
226
Breast Cancer
221
Dizziness
214
Age groups
Adult · 323Elderly · 151

Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Tamoxifen in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.

Tamoxifen FDA approval history

How Tamoxifen went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.

Tamoxifen was first approved by the FDA in 1977 (Brand: NOLVADEX · Astrazeneca); the first generic version was approved in 2003. It remains available in U.S. pharmacies today.

1977
Brand approved
Brand: NOLVADEX · Astrazeneca
2003
First generic approved
Lower-cost ANDA competition begins
2026
Available today
Active in U.S. pharmacies

Source: Drugs@FDA.

Tamoxifen recall history

A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.

The FDA’s enforcement reports list no Tamoxifen recalls since July 2021.

✅No Tamoxifen recalls on record since July 2021

Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.

RxNorm Concept Web — From Ingredient to Every Form and Strength

This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.

Ingredient (IN) Tamoxifen RxCUI 10324 2 dose forms · 4 strengths
  1. Dose form (SCDF) Oral Solution RxCUI 393416 In current FDA listings
    Clinical drug / strength (SCD) 2 MG/ML RxCUI 389230
  2. Dose form (SCDF) Oral Tablet RxCUI 374020 In current FDA listings
    Clinical drug / strength (SCD) 10 MG RxCUI 198240 20 MG RxCUI 313195 40 MG RxCUI 250423

Look up RxCUI 10324 in the RxCUI Atlas →

RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.

💵 What Tamoxifen costs pharmacies (NADAC benchmark)

The national average invoice price pharmacies pay for the drug itself, from CMS's NADAC survey (data as of Sep 30, 2026). This is a supply-cost benchmark — not a retail price and not what you'd pay at the counter.

FormStrengthPharmacy acquisition benchmark
Tablet · Oral 10 mg $0.126 per tablet NDC details & price history
Tablet · Oral 20 mg $0.277 per tablet NDC details & price history
Tablet, Film Coated · Oral 20 mg $0.285 per tablet NDC details & price history
Tablet, Film Coated · Oral 10 mg $0.126 per tablet NDC details & price history
Liquid · Oral 20 mg/10 mL $4.40 per mL NDC details & price history
Why show this? Your out-of-pocket cost depends on insurance, pharmacy markup, and discounts — but the acquisition benchmark tells you whether the medication itself is inexpensive or costly, which strengths cost more per dose, and whether a cash-price quote is in a reasonable range. Each row links to the NDC-level record with its full price history.

Source: CMS National Average Drug Acquisition Cost (NADAC), a survey of retail pharmacy invoice prices. Benchmarks shown are the range across package sizes of a representative product for each form and strength — other manufacturers' products may differ.

Tamoxifen brand names

Tamoxifen is sold under 2 brand names in the FDA directory — Nolvadex, Soltamox. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.

Nolvadex Soltamox

Who makes Tamoxifen: manufacturers and labelers

10 companies list Tamoxifen products with the FDA. By number of product records, the largest are Bryant Ranch Prepack, A-S Medication Solutions, Actavis Pharma, Inc.. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.

Bryant Ranch Prepack 3 A-S Medication Solutions 2 Actavis Pharma, Inc. 2 Aurobindo Pharma Limited 2 Dr. Reddy's Labratories Inc. 2 Mylan Pharmaceuticals Inc. 2 NuCare Pharmaceuticals, Inc. 2 Mayne Pharma 1 Mayne Pharma Commercial LLC 1 Proficient Rx LP 1

Tamoxifen drug class (RxNorm)

Tamoxifen belongs to the Estrogen Agonist/Antagonist class.

Pharmacologic class Estrogen Agonist/Antagonist
Drug family (ATC) Anti-estrogens
How it works Selective Estrogen Receptor Modulators

Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.

Sources for this Tamoxifen page

Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.

📄
FDA-filed drug labels (SPL) Uses, dosing, warnings & side effects from SPL records retrieved through openFDA; the linked representative set can be verified on DailyMed. ✓ Linked label effective Nov 29, 2021
🏭
Forms, brands & labelersAggregated from ingredient-matched FDA National Drug Code Directory product records for Tamoxifen.
📈
Real-world reportsThe FDA Adverse Event Reporting System (FAERS), served through openFDA.
🚨
Recalls & shortagesopenFDA drug-enforcement reports and the FDA drug-shortage database.
🧾 Clinical label set — FDA-filed SPL labels retained for Tamoxifen after exact ingredient or ingredient-combination matching and applicable route/form matching
Clinical labels in scope
15
Finished products in the current FDA directory
18
Companies listing them (makers, repackagers, distributors)
10
FDA labeler codes behind them ⓘ
9
Linked representative label ⓘ
Mayne Pharma
Linked label effective
Nov 29, 2021
Composite sections available
27
Linked SPL Set ID
1e6ff055-590c-41e6-9530-1fdf04cdbd02
Linked SPL Document ID
5bcbc281-342c-4b05-8409-53a08b1fc9f6
Open the linked representative label on DailyMed ↗

How this page is built

HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Mayne Pharma is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →