Anti-androgen drugs block androgen hormones, such as testosterone. People can use them for many purposes, like slowing prostate cancer and minimizing the masculinizing effects of certain hormones.

Androgens are hormones that regulate the development of sex characteristics. Usually, people born with male sex characteristics tend to have high levels of androgens. People born with female characteristics tend to have low levels of androgens. Instead, they often have high levels of estrogen.

Anti-androgen drugs work by blocking the effects of androgens, such as testosterone. They do this by binding to proteins called androgen receptors. They bind to these receptors so that androgens can’t bind to them.

There are several types of anti-androgens. You can usually take them with other medications or during certain surgical procedures.

Anti-androgens have many uses, from managing prostate cancer to reducing unwanted facial hair.

For women

Many women tend to produce few androgens. However, some women may produce more than others.

For example, women with polycystic ovary syndrome (PCOS) often have higher androgen levels. This can cause excess hair growth, acne, and ovulation problems. Anti-androgens can help reduce these symptoms in women with PCOS.

Other conditions that cause high levels of androgens in women include:

Anti-androgens can help manage these conditions and prevent complications caused by high androgen levels in women. These complications include:

For transgender and nonbinary people

For people in transition, anti-androgens can help block some masculinizing effects of testosterone. They can reduce some characteristically male traits, such as:

Anti-androgens can often be most effective for transgender women when they take the medications with estrogen, the primary female sex hormone.

In addition to triggering the development of feminine physical traits, such as breasts, estrogen also indirectly reduces testosterone levels. Taking anti-androgens with estrogen can help to both suppress masculine traits and promote feminine ones.

For people who identify as nonbinary, taking anti-androgens alone can help reduce masculine physical traits.

For men

Androgens stimulate cancer cell growth in the prostate. Lowering androgen levels, or preventing androgens from reaching cancer cells, can help slow down cancer. It may also shrink existing tumors.

In its early stages, prostate cancer cells rely on androgens to feed their growth. Anti-androgens work by blocking androgens from binding to androgen receptors in prostate cancer cells. This starves the cancer cells of the androgens they need to grow.

However, anti-androgens don’t stop androgen production. Medical professionals often combine anti-androgens with other treatments, such as surgical or chemical castration. These combinations are also called:

  • combined androgen blockage
  • complete androgen blockade
  • total androgen blockade

There are several anti-androgens available, each with slightly different uses. Here’s a look at some of the most common ones.


Flutamide is a type of anti-androgen people use with other medications to treat certain types of prostate cancer. Flutamide binds to the androgen receptors in prostate cancer cells, which blocks androgens from binding to the receptors. This prevents androgens from encouraging prostate cancer cell growth.


Spironolactone (Aldactone) is a type of anti-androgen that medical professionals used for years to treat hormonal acne and excessive body hair. People transitioning may take it to reduce masculine traits. Although there’s little evidence to support its use, some doctors also prescribe it for female pattern baldness.


Cyproterone was one of the first anti-androgens. Healthcare professionals used it with other medications to treat women with PCOS. It may also decrease testosterone levels and reduce the production of acne-causing oils.

Doctors might also use it to reduce masculine traits in transgender women. However, due to its side effects, they generally do not prefer it. Cyproterone is currently unavailable in the United States.

Anti-androgens can produce a range of side effects, depending on the dose and type you take.

Some possible side effects include:

  • low sex drive
  • increased risk of depression
  • elevated liver enzymes
  • reduced facial and body hair
  • higher risk of developmental issues for a fetus if you take them during pregnancy
  • hepatitis
  • liver injury
  • erectile dysfunction
  • diarrhea
  • breast tenderness
  • hot flashes
  • menstrual irregularity
  • skin rash
  • anti-androgen resistance, meaning the medication stops working

A healthcare professional can help you choose an anti-androgen that suits your needs and comes with the fewest side effects.

Anti-androgens have many uses for men, women, and people in gender transition, both on their own and combined with other medications and treatments. However, anti-androgens can cause some serious side effects. Work with a doctor to weigh the pros and cons of taking anti-androgens.