The short answer
Hormone therapy is a cancer treatment that slows or stops the growth of cancers that use hormones to grow, such as some prostate and breast cancers. It works either by blocking the body's ability to make hormones or by interfering with how hormones behave. It is most often used along with other cancer treatments.
Hormone therapy slows or stops the growth of cancers that use hormones to grow.
It is used mainly for some prostate and breast cancers.
It works by blocking hormone production or by interfering with how hormones behave.
It is most often used along with other cancer treatments.
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The full explanation.
The simple version
Some cancers use hormones to grow. Hormone therapy slows or stops that growth. It is also called hormonal therapy, hormone treatment, or endocrine therapy.
Hormone therapy is used for two main reasons:
- To treat cancer. It can stop or slow cancer's growth and reduce the chance it will return.
- To ease cancer symptoms. It may be used to reduce or prevent symptoms in men with prostate cancer who cannot have surgery or radiation therapy.
Hormone therapy works against cancers that rely on hormones to grow.
The two broad types
Hormone therapy falls into two broad groups:
- those that block the body's ability to produce hormones
- those that interfere with how hormones behave in the body
Which cancers it treats
Hormone therapy treats prostate and breast cancers that use hormones to grow. It is most often used along with other cancer treatments. Which treatments you need depends on several things. What type of cancer is it? Has it spread, and how far? Does it use hormones to grow? And do you have other health problems?
When used with other treatments, hormone therapy can:
- make a tumor smaller before surgery or radiation therapy (called neoadjuvant therapy)
- lower the risk that cancer will come back after the main treatment (called adjuvant therapy)
- destroy cancer cells that have returned or spread to other parts of your body
Side effects
Hormone therapy blocks your body from making hormones, or changes how hormones behave. So it can cause unwanted side effects. Which ones you get depends on the type of therapy, and on how your body responds. People respond differently. Not everyone gets the same side effects, and some differ between men and women.
Common side effects for men who receive hormone therapy for prostate cancer include:
- hot flashes
- loss of interest in or ability to have sex
- weakened bones
- diarrhea
- nausea
- enlarged and tender breasts
- fatigue
Common side effects for women who receive hormone therapy for breast cancer include:
- hot flashes
- vaginal dryness
- changes in your periods if you have not yet reached menopause
- loss of interest in sex
- nausea
- mood changes
- fatigue
Side effects vary from person to person and can differ for men and women.
What to expect
How it is given. Hormone therapy may be given as pills you swallow. It may be given as an injection, which is a shot in a muscle or under the skin. Or it may be given through surgery to remove the organs that make hormones: the ovaries in women, or the testicles in men.
Where you go. Where you have treatment depends on which therapy you are getting, and how it is given. You may take hormone therapy at home. Or you may have it in a doctor's office, a clinic, or a hospital.
How it may affect you. Hormone therapy affects people in different ways. How you feel depends on your type of cancer, how advanced it is, the type of therapy, and the dose. Your doctors and nurses cannot know for certain how you will feel.
How you will know if it is working
Are you taking hormone therapy for prostate cancer? Then you will have regular PSA tests. If the therapy is working, your PSA levels will stay the same or go down. If they go up, the treatment may no longer be working. Your doctor will then discuss other options with you.
Are you taking hormone therapy for breast cancer? Then you will have regular check-ups. These usually include an exam of the neck, underarm, chest, and breast areas, plus regular mammograms. Your doctor may also order other imaging or lab tests.
Diet
Hormone therapy for prostate cancer may cause weight gain. Talk with your doctor, nurse, or dietitian if weight gain becomes a problem for you.
When to get help sooner
- Call 911 or go to an emergency department if your chest hurts or feels tight, or breath is suddenly hard to find. Sudden numbness or weakness down one side, or speech that will not come out right, belongs in the same group.
- Call your care team the same day if you are taking hormone therapy for breast cancer and have vaginal bleeding outside your normal period. Also call the same day about a calf that becomes swollen, warm, and sore.
- Call your care team within a day or two if diarrhea or nausea is keeping you from eating and drinking, or if bone pain follows a knock that should not have caused it.
Sources: MedlinePlus: tamoxifen and American Cancer Society: hormone therapy for prostate cancer.
Words to know
Tap any term to see what it means.
Common questions
What is hormone therapy for cancer?
Hormone therapy is a cancer treatment that slows or stops the growth of cancer that uses hormones to grow. It is also called hormonal therapy, hormone treatment, or endocrine therapy.
Which cancers does hormone therapy treat?
Hormone therapy is used to treat prostate and breast cancers that use hormones to grow. It is most often used along with other cancer treatments. The types of treatment you need depend on the cancer, whether it has spread, whether it uses hormones to grow, and your other health problems.
How does hormone therapy work?
Hormone therapy falls into two broad groups: those that block the body's ability to produce hormones, and those that interfere with how hormones behave in the body.
How is hormone therapy given?
It may be given in several ways: as pills you swallow (oral), as an injection (a shot), or through surgery to remove organs that produce hormones. In women the ovaries are removed, and in men the testicles are removed.
What side effects can hormone therapy cause?
Side effects depend on the type of therapy and how your body responds, and some differ for men and women. For men treated for prostate cancer, common side effects include hot flashes, loss of interest in sex, weakened bones, and fatigue. For women treated for breast cancer, they include hot flashes, vaginal dryness, changes in periods, and fatigue.
How will I know if hormone therapy is working?
If you take it for prostate cancer, you will have regular PSA tests; stable or falling PSA levels suggest it is working, while rising levels may mean it is not. If you take it for breast cancer, you will have regular check-ups, mammograms, and sometimes other imaging or lab tests.
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Last updated: 2026-08-11Next planned review: 2027-01-02
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How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes. We do not employ clinicians and do not intend to — our work is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and checked line by line against the sources listed on it. That confirms the sources support what the page says. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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