Faslodex (Fulvestrant) for Breast Cancer

What Members Say Top Tips Side Effects Copay Help FAQs

Faslodex (fulvestrant) is a prescription medication approved by the U.S. Food and Drug Administration (FDA) to treat certain adults with hormone receptor-positive breast cancer.

What Members Say

MHT logo These insights are based on 1,514 comments about Faslodex from MyBCTeam members. These are the experiences of a small number of individuals and are not meant to be medical advice.

Benefits:

Treatment can keep scans stable or lower tumor markers for months or years.
Monthly maintenance dosing can feel manageable after the initial dosing schedule.
Some have few side effects beyond brief soreness after injections.

Considerations:

Two slow, deep hip injections can be painful and may leave lumps or knots.
Bone, joint, muscle, leg, or back pain can be significant.
Fatigue, hot flashes, headaches, nausea, and constipation can occur.

How Faslodex Works and How It’s Taken

Faslodex is an estrogen receptor antagonist. It attaches to estrogen receptors and lowers the amount of these receptors in breast cancer cells. Some breast cancers use estrogen signals to grow.

By blocking estrogen activity, Faslodex may help slow cancer growth. Doctors prescribe Faslodex when certain adults have hormone receptor-positive advanced or metastatic breast cancer. The exact use depends on whether the cancer is HER2-negative, whether it is advanced or metastatic, whether endocrine therapy has been used before, and whether Faslodex is used alone or with another treatment.

Faslodex may be used:

Alone for HR-positive, HER2-negative advanced breast cancer in postmenopausal women who have not previously received endocrine therapy
Alone for HR-positive advanced breast cancer in postmenopausal women whose cancer has progressed after endocrine therapy
With ribociclib for HR-positive, HER2-negative advanced or metastatic breast cancer in postmenopausal women as initial endocrine-based therapy or after disease progression on endocrine therapy
With palbociclib or abemaciclib for HR-positive, HER2-negative advanced or metastatic breast cancer in women whose cancer has progressed after endocrine therapy

Faslodex is given as an injection into the muscle of the buttocks by a healthcare professional. It is usually given on day 1, day 15, day 29, and then once a month after that.

When Faslodex is used with palbociclib, abemaciclib, or ribociclib, those medicines are taken by mouth according to their own prescribing schedules.

Typical Dosing for Breast Cancer

The recommended dose of Faslodex is 500 milligrams given as two injections, one in each buttock, on day 1, day 15, day 29, and then once monthly after that. The same Faslodex dose is used when it is given alone or with palbociclib, abemaciclib, or ribociclib.

When Faslodex is used with other cancer medicines such as palbociclib, abemaciclib, or ribociclib, your healthcare provider may adjust your treatment plan based on your individual needs.

For people with moderate liver problems, the recommended dose is 250 milligrams given on day 1, day 15, day 29, and then once monthly after that.

This information is based on the prescribing information, but your healthcare provider may tailor your treatment plan. Always follow their guidance.

Top Advice From Members on Faslodex

MHT logo These insights are based on 1,514 comments about Faslodex from MyBCTeam members.

Members who use Faslodex often talk about preparing for the injections, watching for side effects, and staying in close contact with their care team. Many say the experience varies a lot from person to person, so practical tips like tracking symptoms, planning for soreness, and asking questions about timing or lab work can help.

1

Expect soreness, and plan for a slow injection.
“I received Faslodex shots for one year. I only had soreness at the injection site. It depends on how fast they give it also. It’s very thick, almost like aloe vera juice. They’re supposed to give it to you in your upper hip muscle so they don’t hit the sciatic nerve back there. And it should be given very slowly! It does make a difference!”
2

Keep track of side effects after each dose.
“Hola …. I find that about four days after my monthly Faslodex shot I feel really sad/depressed. I counteract by moving, but it is real. I’ve been tracking this for like six months now.”
3

Talk to your doctor about side effects that affect daily life.
“It really depends on the person. I am now on Faslodex injections once a month and have no side effects. Hopefully, you won’t have any like me, but if you do be sure to discuss them with your medical team.”

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Faslodex Side Effects

In clinical studies of Faslodex for hormone receptor-positive, HER2-negative advanced or metastatic breast cancer in postmenopausal women, the most common side effects occurred in at least 5 percent of people taking Faslodex.

These side effects include:

Injection site pain
Nausea
Bone pain
Muscle pain
Arthralgia (joint pain)
Headache
Back pain
Fatigue
Pain in extremity
Hot flash
Vomiting
Anorexia (loss of appetite)
Asthenia (extreme weakness)
Musculoskeletal pain
Cough
Dyspnea (shortness of breath)
Constipation
Increased hepatic enzymes (ALT, AST, and ALP)

Serious Side Effects and Warnings

Faslodex can cause serious side effects that may require immediate medical attention. These include:

Severe allergic reactions — These can include hives, swelling of the face, lips, tongue, or throat, and trouble breathing.
Bleeding problems — The risk may be higher in people with bleeding disorders, low platelet counts, or those taking blood thinners.
Injection site reactions — These can include sciatica, nerve pain, numbness, tingling, or weakness in the legs.
Embryo-fetal toxicity — Faslodex can harm your baby if you are pregnant.
False estradiol test results — Faslodex can interfere with some lab tests.

Get medical help right away if you think you are having a serious reaction.

How To Save on Faslodex

AstraZeneca, the manufacturer of Faslodex, offers the Faslodex Co-Pay Savings Program. Eligible people with commercial insurance may pay as little as $0 per dose.

People are not eligible if their prescriptions are paid by any state or federally funded programs, including Medicare Part B, Medicare Part D, Medicaid, Medigap, Veterans Affairs, Department of Defense, or TRICARE.

The Faslodex Co-pay Savings Program is available through AstraZeneca Access 360, which offers help with insurance and cost questions, and information on affordability options. To learn more, visit the Faslodex patient affordability page, or call 844-275-2360.

What To Know Before Taking Faslodex

Tell your doctor if you have any allergies to fulvestrant or any ingredients in Faslodex. Do not take Faslodex if you have had a serious allergic reaction to fulvestrant or any of its ingredients.

Tell your doctor about all medicines you take, including prescription drugs, over-the-counter medicines, vitamins, and herbal supplements. Especially tell your doctor if you take a blood thinner medicine.

Before starting Faslodex, tell your doctor about all of your medical conditions, including if you:

Have a low level of platelets in your blood or bleed easily
Have liver problems

Tell your doctor if you:

Are pregnant or plan to become pregnant
Are breastfeeding or plan to breastfeed

Females who are able to become pregnant:

Your doctor may perform a pregnancy test within seven days before you start Faslodex.
Use effective birth control during treatment with Faslodex and for one year after your last dose.
Tell your doctor right away if you become pregnant or think you may be pregnant during treatment.

Faslodex can harm your baby if you are pregnant.

Do not breastfeed during treatment with Faslodex and for one year after your last dose.

Community FAQs

These answers are fact-checked by our editorial staff.

How effective is Faslodex?

In one study, postmenopausal women with HR-positive, HER2-negative locally advanced or metastatic breast cancer who had not previously received endocrine therapy received either Faslodex or anastrozole. Median progression-free survival, which is the length of time before the cancer got worse, was 16.6 months with Faslodex and 13.8 months with anastrozole.

In another study, postmenopausal women with advanced breast cancer whose cancer had progressed after endocrine therapy received either Faslodex 500 milligrams or Faslodex 250 milligrams. Median progression-free survival was 6.5 months with Faslodex 500 milligrams and 5.4 months with Faslodex 250 milligrams. Median overall survival was 26.4 months with Faslodex 500 milligrams and 22.3 months with Faslodex 250 milligrams.

In a study of Faslodex used with ribociclib, median progression-free survival was 20.5 months with Faslodex plus ribociclib and 12.8 months with Faslodex plus placebo (an inactive treatment).

Can Faslodex cause injection pain or nerve problems in breast cancer treatment?

Yes. Injection site pain is one of the most commonly reported side effects of Faslodex. Injection site-related nerve problems have also been reported, including sciatica, neuralgia, neuropathic pain, and peripheral neuropathy.

Tell your healthcare provider if you develop symptoms such as numbness, tingling, or weakness in your legs after a Faslodex injection.

Can Faslodex be used with other medicines for breast cancer?

Yes. Faslodex may be used alone or with other medicines for certain people with hormone receptor-positive (HR-positive), HER2-negative advanced or metastatic breast cancer. These medicines may include palbociclib, abemaciclib, or ribociclib, depending on the type of breast cancer and previous treatment history.

According to the prescribing information, no clinically relevant drug interaction was seen when Faslodex was used with palbociclib, abemaciclib, or ribociclib. The prescribing information also states that there are no known drug-drug interactions with Faslodex.