Fulvestrant (Intramuscular)


This drug works by blocking estrogen within the body, preventing the growth and spread of any existing tumors. This drug is only available via prescription and you should be screened thoroughly before receiving this drug. Because of its precise nature, it should only be given involving specific types of breast cancer.

If your doctor has recommended you for this medication, it is because they think it is the best option for you. Blocking a tumor's access to estrogen can prevent further growth. This drug may be used therapeutically, or in tandem with stronger treatments, like surgery or chemotherapy.

This drug is a strong hormone blocker and shouldn't be used by women who have not experienced menopause. If you are under 40 or 50 and have not gone through this stage in your life, your doctor may suggest a different treatment for your breast cancer. Fulvestrant is a powerful drug and should only be taken if the benefits outweigh the risk.

Because this drug is so strong, it may cause side effects. Your doctor may prescribe other medications to alleviate this or give you tips on how to cope with these issues. If your side effects persist or become serious, talk to your doctor. This drug is not guaranteed to work on everyone. Make sure to show up for all of your appointments and keep a close eye on your own symptoms during your treatment.

Your doctor will let you know if this drug is working. You may not be able to tell if this drug has any effect, so you may need to have scans or tests done to determine how your treatment is going. Your doctor is recommending this medication because they believe it has a good chance of succeeding, so try to keep an open mind about the side effect and success rate.

Conditions Treated

  • Breast cancer, specifically hormone-receptor positive metastatic breast cancer

Type Of Medication

  • Estrogen blocker
  • Hormonal drug

Side Effects

Because of the strong nature of this drug, it may come with side effects. These side effects can vary between mild and severe, and may change the longer you take this drug. Some side effects may lessen or disappear entirely, while other side effects may appear the longer you take this medication.

While side effects are unpleasant, they may be a normal part of the treatment. If you have questions or concerns about how this drug is affecting you, be sure to mention this to your doctor. They may be able to offer advice, natural remedies, or non-interactive medications as a solution. For example, you may be able to take an anti-nausea medication in tandem with your Fulvestrant treatment.

Some side effects are mild and do not require your doctor's immediate attention. These side effects may go away on their own, so do not panic if you experience them. Mild side effects include:

  • Nausea or vomiting
  • Various aches and pains
  • Occasional lightheadedness
  • Changes in mood
  • Loss of appetite
  • Trouble sleeping
  • Malaise (general feeling of discomfort and illness)

This list is not exhaustive, and you may experience additional side effects. If your side effects begin to affect your daily life, talk to your doctor about possible solutions. In some cases, your side effects can be alleviated by medication or change in lifestyle.

Some side effects are more serious, and may require your doctor's attention. Serious side effects can include:

  • Swelling of the face and extremities, including your arms and legs
  • Tingling in the hands and feet
  • Sudden, unexpected weight loss
  • Sudden, unexpected weight gain

Some other side effects may occur that warrant your doctor's attention. Be sure to tell your doctor if you experience anything unusual or troubling, and keep them updated on your condition. Things like unusual bleeding and bruising, severe migraines and loss of coordination should be noted and taken to your doctor.

While rare, some patients may actually be allergic to Fulvestrant. Allergies can quickly become fatal if left untreated, so alert someone immediately if you experience allergy symptoms. Do not take Fulvestrant if you have an existing allergy to any of the active or inactive ingredients, and do not continue taking Fulvestrant if you react badly to the first dose.

Allergy symptoms can include:

  • Trouble breathing
  • Closing of the airways
  • Swelling of the face/mouth/lips/tongue
  • Severe swelling at the injection site

Be sure to tell your doctor if you have had an allergic reaction to Fulvestrant or any drugs of its kind. You do not need to feel obligated to continue your Fulvestrant treatment after an adverse reaction. The chances are that other measures can be taken to treat your breast cancer.


This drug will be given to you via injection by a trained nurse or doctor as a shot into the buttocks. You will receive it once a month and it is given as a slow injection to avoid swelling or discomfort. Any knots under the skin should disappear over the next few days.

For your first monthly dose, your doctor may require you to come in two to three times. You will receive shots on days 1, 15, and 29 of the first month. From then on, you will only need one Fulvestrant injection per month.

This drug will be given in a sterile environment with a clean needle, so there is no need to take this drug home or worry about administration. All you need to do is show up for your monthly injections. Make sure to create your schedule with these appointments in mind and avoid missing doses. If you must miss a dose, reschedule your appointment for the earliest opportunity.

Your dose may change over time as your treatment progresses or it may stay static. Talk to your doctor if you have questions about this drug and how it is being given to you.


This drug may interact with some of your other medications or conditions. Be sure to keep a detailed list of all your current medications, including over the counter drugs and herbal remedies.

Your doctor may ask that you stop or lower the dose of your current medications to avoid interactions. While unpleasant, this is for your safety. Interactions can vary between mild to severe, but they can become problematic over time. Some interactions can cause your body to process this drug differently, affecting your treatment, while others can cause toxic build-up.

Be sure to tell your doctor if you are taking any other medications. Do not begin any new prescriptions without your doctor's approval and avoid taking drugs that are not on your pre-approved list. If you have questions about which medications are safe to take, contact your doctor.

If you suffer from blood problems like thrombocytopenia (low platelet rates), be sure to tell your doctor. This drug may aggravate those conditions and cause complications with your treatment. If you suffer from liver problems, notify your doctor. If your body is unable to properly rid itself of this drug, you may experience increased side effects.

Depending on which interactions may occur, your doctor may lower your Fulvestrant dose. If you have concerns about how this will affect your treatment, bring these up before your next shot.


Like all medications, this drug comes with risks and warnings. Some people may be more at risk than others, but all patients receiving Fulvestrant injections should be aware of the precautions.

If you have an allergy to Fulvestrant or similar drugs, do not take this medication. Doing so may cause an allergic reaction. Allergic reactions can be dangerous, or even fatal, so do not take this drug if you've had a previous allergic reaction.

Try to avoid taking blood thinners on this medication. While there is no outright interaction, blood thinners can increase your risk of bleeding problems. Be sure to talk to your doctor if you experience any blood problems while using Fulvestrant.

If you are pregnant, plan on becoming pregnant or get pregnant while taking this drug, tell your doctor immediately. Taking Fulvestrant while pregnant can harm the unborn child. Use effective birth control and do not become pregnant until one year has passed since your last dose.

This drug can cause sterility in men and women. If this is a major concern for you, talk to your doctor about these risks.

You may require additional blood tests during your Fulvestrant treatment. These are just to make sure that the drug is working properly and to ensure that your health is not being affected by the drug. Schedule these tests with your doctor and make sure you show up for your appointments.


Medical staff are trained to handle, prepare and give these injections. Because this drug is given to you at a secure location, you do not need to take it home or store it yourself. The nurses and doctors know how to store this medication within the hospital or care center, so you do not need to worry about how it is being handled.

This drug is given as an injection, so it takes a solution form. This solution is then given as an injection under the muscle. The doctor or nurse will do this slowly with a new, sterile needle. You should not have to give this injection yourself at any point. Even if you are unable to travel to the hospital, a house-call may be made to give you your monthly injection.

If you have questions or concerns about the storage and handling of this medication, ask your nurse or doctor. They should be happy to give you insight on your medication.


Fulvestrant has been proven to help reduce the growth and spread of breast cancer. While no cancer medication is 100% successful, this drug can substantially improve your condition. Your doctor may recommend this drug if you are suffering from hormone-receptive breast cancer and have already gone through menopause. In these cases, Fulvestrant can be an effective and reliable treatment.

This drug can cause side effects. If these side effects become troubling or painful, talk to your doctor. Fulvestrant may be used alongside surgery or chemotherapy. Talk to your doctor about your treatment plan and discuss which options are best for you. While cancer treatment can be unpleasant, modern medicine has made it possible to combat this disease.

If you think Fulvestrant is right for you, talk to your doctor about possible treatment with this drug. Your doctor may give you websites or pamphlets to research before your first dose. Make sure you understand all the given information, and bring any questions/concerns to your doctor.