What is Emcyt (Estramustine Phosphate Sodium)?

Emcyt is an oral medication prescribed to treat prostate cancer. Emcyt contains estramustine, which belongs to a group of drugs called antineoplastics. Estramustine breaks down in the body to form estrogens (estrone, estradiol). Estrogens interfere with prostate cancer by reducing testosterone production, which many cancers rely on for growth. This slows the growth of the tumour.

Estramustine Phosphate Sodium
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Prescription Required.Product of Canada.Shipped from Canada.

What is Emcyt (Estramustine Phosphate Sodium)?

Emcyt is an oral medication prescribed to treat prostate cancer. Emcyt contains estramustine, which belongs to a group of drugs called antineoplastics. Estramustine breaks down in the body to form estrogens (estrone, estradiol). Estrogens interfere with prostate cancer by reducing testosterone production, which many cancers rely on for growth. This slows the growth of the tumour.


Emcyt is to be taken orally, 3-4 times daily as directed by your doctor. It should be taken on an empty stomach, one hour before eating or two hours after. Take it with a full glass of water. Emcyt should be taken regularly to achieve the full benefit, and it is best if it is taken at the same time each day. The prescribed dosage is dependent on the severity of your condition, your weight, and how you respond to treatment.

Be careful to take Emcyt three hours before or after other medications containing magnesium, aluminium, or calcium, dairy products such as milk or yoghurt, sucralfate, bismuth subsalicylate, iron, or zinc. These prevent the absorption of estramustine by binding with it before it can take effect in the body.


The US product should be stored between 36-46 degrees F (2-8°C) in the refrigerator. The Canadian product should be stored between 36-77 degrees F (2-25°C). Keep in the original, labelled container until it is time to take it. Keep out of direct light and away from moisture. Do not store in the bathroom. Keep out of reach of children and pets. Do not consume expired medication. Dispose of expired or surplus medication responsibly, following the instructions of your healthcare provider. Do not flush this medication down the toilet or sink.

Side Effects

Common Side Effects

All medication comes with a risk of side effects. It is important to recognise that your doctor has determined your risk of side effects is outweighed by the potential benefit this medication can provide. Side effects will differ between individuals and it is possible that you will not experience any at all. Common side effects associated with Emcyt include:

  • Nausea
  • Vomiting
  • Appetite loss
  • Flushing
  • Dry skin
  • Headache
  • Cramp in the legs
  • Reduced libido or performance
  • Male breast tenderness or enlargement

If you experience any of these symptoms and they concern you, or they worsen or do not resolve on their own, contact your healthcare provider.

This medication can also cause an increase in blood pressure. Monitor your blood pressure regularly and contact your doctor if you notice any abnormal changes.

Severe Side Effects

Occasionally, Emcyt can be associated with severe side effects that should be taken seriously. These include changes in mood or mental state (depression, anxiety), swelling of the hands or feet, new or worsening seizures, or impaired control of diabetes (increased thirst or urination).

Rarely, Emcyt can cause blood clots, stroke, or heart attacks. If you experience pain in the chest, jaw, and left arm, a sudden and severe headache, weakness on one side of the body, confusion, difficulty speaking, changes in vision, pain or swelling of the leg, breathlessness, or coughing up blood, seek emergency medical assistance.

If you experience easy bruising, abdominal pain, nausea and/or vomiting that won’t stop, dark or discoloured urine, or yellowing of the skin or eyes, contact your doctor right away.

Emcyt can reduce the immune response to infection. Contact your doctor if you have symptoms of infection such as fever or sore throat.

A severe allergic reaction to Emcyt is rare, but not impossible. Seek emergency medical assistance if you develop allergic reaction symptoms, such as a rash, itching, facial swelling, dizziness, or difficulty breathing.

This is not an exhaustive list of side effects. If you experience any abnormal changes that concern you, contact your doctor for assistance.

Warnings & Precautions

Medical History

Before starting Emcyt, ensure your doctor is aware of your complete personal and family medical history. Do not take Emcyt if you are allergic to any of its ingredients. Tell your doctor if you have a history of stroke or blood clots, bone disease, high cholesterol, depression, diabetes, migraines, heart disease, high blood pressure, kidney or liver disease, or seizures.


Smoking cigarettes or using tobacco alongside taking oral estrogen increases the risk of stroke, blood clots, hypertension, and heart attack. Do not smoke cigarettes or use tobacco.


Prior to having surgery, ensure all medical personnel involved in your care are aware of your complete medication schedule, including prescription and non-prescription medications. If you are going to be confined to a bed or chair for a long period of time (such as a long-haul flight), tell your doctor, as they may want to impose special precautions to mitigate your risk of blood clots.

Contact Lenses

If you wear contact lenses or are nearsighted, Emcyt may cause vision problems or make wearing your contact lenses difficult. Contact your optometrist for more information.


Emcyt can cause blotchy patches on your skin, which can be worsened by sunlight. Limit your sunlight exposure and avoid tanning booths. Always apply sunscreen and wear protective clothing.

Sexual Changes

Emcyt can affect sperm production, lead to erectile dysfunction, or reduce libido or sexual performance. Consult your doctor if you experience any of these symptoms.  Reliable birth control should be used while taking this medication. Ask your doctor if you are unsure.


This medication is not typically prescribed in biological females, and is therefore unlikely to be an issue with pregnant or breast feeding people.

Blood Sugar

Emcyt can increase blood sugar levels in diabetics and non-diabetics. Monitor your blood sugar regularly while taking this medication. If you experience a noticeable increase in thirst, urination, hunger, blurred vision, or fruity breath, inform your healthcare provider. If you are diabetic ensure you are monitoring your blood sugar closely.

Interactions & Contraindications

When two or more medications are taken concurrently they can interact with one another, changing how one or more function in the body or leading to unwanted side effects. It is important that interactions are minimised. Keep a comprehensive list of all the medications you take on a regular basis, including prescription and non-prescription, and share this with your doctor. Do not stop, start, or change the dosage of any medications without first asking your doctor.

Emcyt can have very serious interactions with aromatase inhibitors, troleandomycin, and tranexamin acid. These should not be taken alongside Emcyt. If you are already taking these medications, tell your doctor as they will likely adjust your medication schedule to accommodate Emcyt.

Emcyt is contraindicated with corticosteroids, ospemifene, tamoxifen, and hypothyroidism medication. Tell your doctor if you are taking any of these products.

Other medications can affect the levels of estrogen in your body, such as azole antifungals, antibiotics (e.g. penicillins, tetracyclines), bexarotene, griseofulvin, HIV protease inhibitors such as ritonavir, rifamycins, seizure medications, and St John’s wort.

This is not a complete list of possible interactions with Emcyt. If you are concerned about any medications you are taking or you wish to start a new medication, ask your doctor or pharmacist.

Frequently Asked Questions

Emcyt contains estramustine, which belongs to a group of medications referred to as antineoplastics. It is prescribed to treat some forms of prostate cancers. Estramustine breaks down into estrogens in the body, interfering with the proliferation and growth of prostate cancer cells.

You should continue taking Emcyt for as long as your doctor tells you to. It may take one to three months for them to determine if it is improving your condition. Do not stop taking this medication without first consulting your doctor.

People who are allergic to the ingredients of Emcyt should not take it. Emcyt usage is contraindicated in people with diabetes, low blood calcium, low immunity, high blood pressure, high blood clot risk, previous heart attacks, or frequent migraines. Emcyt is not typically prescribed to biological females.

If you forget to take a dose of Emcyt, take it as soon as you remember. If you remember close to the time of your next scheduled dose, skip the missed dose altogether. Take the following dose according to your medicine schedule. Do not take both doses at the same time to catch up.

If you suspect an overdose, seek emergency medical assistance right away. Symptoms of overdose include difficulty breathing and loss of consciousness.

There is a slim chance that Emcyt can be associated with weight gain. If you notice unusual changes in your weight, contact your doctor for what to do next.

No, Emcyt is only available by prescription. Do not take Emcyt unless your doctor has prescribed it to you, and if you are taking Emcyt, do not share this medication with anyone else, even if they have the same condition as you. Ask your doctor if Emcyt is right for you.