Fulvestrant (Faslodex)

The basics

Fulvestrant (brand name- Faslodex) is an FDA-approved treatment used alone or in combination with ribociclib (Kisqali®) for certain types of hormone receptor-positive, advanced breast cancer (breast cancer that depends on hormones such as estrogen to grow) in women who have experienced menopause (change of life; end of monthly menstrual periods) and have not previously been treated with an anti-estrogen medication such as tamoxifen (Nolvadex).

Fulvestrant injection is also combined with palbociclib (Ibrance®) or abemaciclib (Verzenio®) for breast cancer. It is in a class of medications called estrogen receptor antagonists. It works by blocking the action of estrogen on cancer cells. This can slow or stop the growth of some breast tumors that need estrogen to grow.

Let us walk you through the key things you need to know about Fulvestrant.

How should I take fulvestrant (Faslodex)?


Fulvestrant comes as a solution (liquid) to be injected slowly over 1 to 2 minutes into a muscle in the buttocks by a doctor or nurse in a medical facility. It is usually given once every 2 weeks for the first 3 doses (days 1, 15, and 29) and then once a month thereafter. You will receive your dose of medication as two separate injections (one in each buttock).

Ask your doctor or pharmacist for a copy of the manufacturer’s information for the patient.

Do not stop taking fulvestrant without talking to your doctor. You can help them by tracking your side effects in Ankr.

What are the side effects of fulvestrant (Faslodex)?

Common side effects

Serious side effects

Fulvestrant may cause other side effects. Call your doctor if you have any unusual problems while receiving this medication. If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online or by phone (1-800-332-1088).

Use the free Ankr platform or Ankr app to track your symptoms.

What special precautions should I follow?

Before receiving fulvestrant (Faslodex)

  • tell your doctor about your allergies
  • tell your doctor about other intakes
  • tell your doctor if you have or have ever had any disease, symptom, or treatment
  • tell your doctor if you are pregnant, or plan to become pregnant. Talk to your doctor about birth control methods that you can use during your treatment.

While you are on fulvestrant (Faslodex)

  • Tell your doctor if you become pregnant during your treatment with fulvestrant. Fulvestrant may harm the fetus.
  • tell your doctor if you are breastfeeding. You should not breastfeed during your treatment with fulvestrant and for 1 year after receiving the final dose.

I forgot a dose. What should I do?

If you miss an appointment to receive a dose of fulvestrant, call your doctor as soon as possible.

In case of an emergency/overdose

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can’t be awakened, immediately call emergency services at 911.

What special dietary instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

Brand names

  • Faslodex®

Last Revised -06/15/2023, FDA-updated- 05/15/2019, SG

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DISCLAIMER: No part of this content constitutes medical advice, opinion, or should be used for medical decision making without consultation with a licenced medical practitioner and under a patient-provider relationship. All information on the website is provided without any claims of accuracy. For full terms and conditions, visit this link. Content curated by the Ankr team.

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