Tamoxifen citrate tablets USP, a nonsteroidal antiestrogen, are for oral administration. Each tablet contains 10 mg or 20 mg tamoxifen (equivalent to 15.2 mg or 30.4 mg, respectively, of tamoxifen citrate, USP). Each tablet contains the following inactive ingredients: croscarmellose sodium, hypromellose, lactose (monohydrate), magnesium stearate, polyethylene glycol 400, povidone, corn starch, and titanium dioxide. Chemically, tamoxifen is the trans-isomer of a triphenylethylene derivative. The chemical name is (Z)2-[4-(1,2-diphenyl-1-butenyl)phenoxy]- N , N -dimethylethanamine 2-hydroxy-1,2,3- propanetricarboxylate (1:1). The structural formula, empirical formula, and molecular weight are as follows: C 32 H 37 NO 8 M.W. 563.62 Tamoxifen citrate has a pKa' of 8.85, the equilibrium solubility in water at 37°C is 0.5 mg/mL and in 0.02 N HCl at 37°C, it is 0.2 mg/mL.

What kind of drug is tamoxifen?

The FDA classifies tamoxifen as an estrogen agonist/antagonist. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.

Can you take tamoxifen with other medicines?

It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run tamoxifen against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.

What brand names is tamoxifen sold under?

We track 3 tamoxifen-containing products in the U.S.: Tamoxifen Citrate, Nolvadex and Soltamox. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.

What forms does tamoxifen come in?

Across the brands we track, tamoxifen is currently marketed as tablet and liquid, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.

Is there a generic tamoxifen?

Yes. Our catalog lists 1 generic tamoxifen product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.

Tamoxifen: uses, dosing, side effects & brands

Tamoxifen is an estrogen agonist/antagonist sold in the U.S. under 3 brand and generic names, for breast neoplasms, gynecomastia and pancreatic neoplasms. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.

By the pharmaranks editorial teamReviewed against the FDA (openFDA label, NDC Directory & Enforcement) sourcesHow we research

Key facts

Drug class: Estrogen Agonist/Antagonist
Treats: Breast Neoplasms, Gynecomastia and Pancreatic Neoplasms
Available as: Tablet · Liquid
Sold as: 3 products — Tamoxifen Citrate, Nolvadex and Soltamox
Prescription?: Prescription only
Generic available?: Yes
Typical price: about $8 for a 30-count supply
Boxed warning: Boxed warning

How tamoxifen is dosed

From the FDA label for Tamoxifen Citrate (application ANDA090878). Other tamoxifen products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.

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 20 mg daily for 5 years. Reduction in Breast Cancer Incidence in High Risk Women The recommended dose is tamoxifen 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…

Tamoxifen side effects

to tamoxifen are relatively mild and rarely severe enough to require discontinuation of treatment in breast cancer patients. Continued clinical studies have resulted in further information which better indicates the incidence of adverse reactions with tamoxifen as compared to placebo. Metastatic Breast Cancer Increased bone and tumor pain and, also, local disease flare have occurred, which are sometimes associated with a good tumor response. Patients with increased bone pain may require additional analgesics. Patients with soft tissue disease may have sudden increases in the size of preexisting lesions, sometimes associated with marked erythema within and surrounding the lesions and/or the development of new lesions. When they occur, the bone pain or disease flare are seen shortly after starting tamoxifen and generally subside rapidly. In patients treated with tamoxifen for metastatic breast cancer, the most frequent adverse reaction to tamoxifen is hot flashes. Other adverse reactions which are seen infrequently are hypercalcemia, peripheral edema, distaste for food, pruritus vulvae, depression, dizziness, lightheadedness, headache, hair thinning and/or partial hair loss, and vaginal dryness. Premenopausal Women The following table summarizes the incidence of adverse reactions reported at a frequency of 2% or greater from clinical trials (Ingle, Pritchard,…

Every tamoxifen product we track (3)

Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.

Tamoxifen products
#	Drug	Rating	Type	Form	Generic?	Typical price
1	Tamoxifen Citrate Boxed warning	62/100	Prescription	Tablet	Generic	$8	View →
2

What tamoxifen pills look like

Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.

Tamoxifen pill imprints
Imprint	Strength	Colour	Shape	Maker
T10	10 mg	white	round	—
2232;WPI	10 mg	white	round	—
2232;WPI	10 mg	white	round	—
2232;WPI	10 mg	white	round	—
2233;WPI	20 mg	white	round	—
2233;WPI	20 mg	white

Frequently asked questions

What is tamoxifen?: Tamoxifen citrate tablets USP, a nonsteroidal antiestrogen, are for oral administration. Each tablet contains 10 mg or 20 mg tamoxifen (equivalent to 15.2 mg or 30.4 mg, respectively, of tamoxifen citrate, USP). Each tablet contains the following inactive ingredients: croscarmellose sodium, hypromellose, lactose (monohydrate), magnesium stearate, polyethylene glycol 400, povidone, corn starch, and titanium dioxide. Chemically, tamoxifen is the trans-isomer of a triphenylethylene derivative. The chemical name is (Z)2-[4-(1,2-diphenyl-1-butenyl)phenoxy]- N , N -dimethylethanamine 2-hydroxy-1,2,3- propanetricarboxylate (1:1). The structural formula, empirical formula, and molecular weight are as follows: C 32 H 37 NO 8 M.W. 563.62 Tamoxifen citrate has a pKa' of 8.85, the equilibrium solubility in water at 37°C is 0.5 mg/mL and in 0.02 N HCl at 37°C, it is 0.2 mg/mL.
What kind of drug is tamoxifen?: The FDA classifies tamoxifen as an estrogen agonist/antagonist. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
Can you take tamoxifen with other medicines?: It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run tamoxifen against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What brand names is tamoxifen sold under?: We track 3 tamoxifen-containing products in the U.S.: Tamoxifen Citrate, Nolvadex and Soltamox. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.
What forms does tamoxifen come in?: Across the brands we track, tamoxifen is currently marketed as tablet and liquid, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.

Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.

Tamoxifen drug interactions

When tamoxifen is used in combination with coumarin-type anticoagulants, a significant increase in anticoagulant effect may occur. Where such coadministration exists, careful monitoring of the patient's prothrombin time is recommended. In the NSABP P-1 trial, women who required coumarin-type anticoagulants for any reason were ineligible for participation in the trial (see CONTRAINDICATIONS ). There is an increased risk of thromboembolic events occurring when cytotoxic agents are used in combination with tamoxifen. Tamoxifen reduced letrozole plasma concentrations by 37%. The effect of tamoxifen on metabolism and excretion of other antineoplastic drugs, such as cyclophosphamide and other drugs that require mixed function oxidases for activation, is not known. Tamoxifen and N-desmethyl tamoxifen plasma concentrations have been shown to be reduced when coadministered with rifampin or aminoglutethimide. Induction of CYP3A4-mediated metabolism is considered to be the mechanism by which these reductions occur; other CYP3A4 inducing agents have not been studied to confirm this effect. One patient receiving tamoxifen with concomitant phenobarbital exhibited a steady-state serum level of tamoxifen lower than that observed for other patients (i.e., 26 ng/mL vs. mean value of 122 ng/mL). However, the clinical significance of this finding is not known. Rifampin induced…