Lupron is a drug doctors prescribe to treat prostate cancer. It works by reducing testosterone levels in the body, slowing cancer growth.

Lupron is the brand name for leuprolide acetate. Lupron belongs to a class of drugs called luteinizing hormone-releasing hormone (LHRH) agonists. These medications block the production of LHRH in the body, which results in the testicles producing less testosterone.

Lupron is one of several drugs doctors may prescribe to help fight prostate cancer by reducing testosterone levels in the body.

In this article, we explore how Lupron works, how effective it is, and what to expect during treatment. We also discuss testosterone flares, side effects, and the outlook for people with prostate cancer.

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Lupron and other LHRH agonists are forms of hormone therapy. For people with prostate cancer, the aim of hormone therapy is to reduce testosterone levels in the body.

Male hormones, such as testosterone, encourage the growth of prostate cancer cells. Lowering testosterone levels in the body can help slow the progression of prostate cancer.

Doctors typically prescribe hormone therapy for people with late-stage prostate cancer or prostate cancer that returns. Some doctors use hormone therapy when the disease is in the early stages, but the American Cancer Society (ACS) recommends watching and waiting as the best approach for early-stage prostate cancer.

Hormone therapies, such as Lupron, are often effective in combination with other treatments for people with late-stage prostate cancer. Many doctors do not recommend hormone therapy during the early stages of this disease.

One potential issue is that prostate cancer can become resistant to LHRH agonists over time in some people.

According to the ACS, doctors may recommend hormone therapies, such as Lupron, for:

  • cancer that comes back after radiation therapy or surgery
  • cancer that has spread too far for radiation therapy or surgery to cure it
  • people who cannot have radiation therapy or surgery
  • shrinking cancer before radiation therapy
  • people who are having radiation therapy and have a high risk of cancer returning after treatment

Doctors often use hormone therapies, such as Lupron, in combination with radiation therapy or other treatments. They may also use it following surgery.

Healthcare professionals administer Lupron as a depot, a small implant that they inject under the person’s skin. The individual can often choose an injection site that is suitable for them.

Common injection sites include:

  • upper arms
  • outer thighs
  • buttocks

The treatment regimen for Lupron will depend on the individual’s circumstances, and a person can work with their doctor to determine the best course of treatment.

Some typical dosages include:

  • 7.5 mg — one injection every 4 weeks
  • 22.5 mg — one injection every 12 weeks
  • 30 mg — one injection every 16 weeks
  • 45 mg — one injection every 24 weeks

When a person starts treatment with Lupron, they may have a testosterone flare. Later on, they may experience side effects due to having very low testosterone levels in their body. After treatment stops, testosterone levels begin to return to normal.

When a person first takes Lupron, their testosterone levels may rise, or flare, before dropping to very low levels. For some people, particularly those with advanced prostate cancer, a testosterone flare can temporarily cause their symptoms to worsen.

The symptoms of a testosterone flare can include:

  • blockage of the ureters, the tubes that carry urine from the kidneys to the bladder
  • bone pain
  • worsening nerve symptoms
  • spinal cord compression
  • issues with urination

To help prevent a testosterone flare, doctors may also prescribe an anti-androgen drug during the first few weeks of treatment with an LHRH agonist.

As with any medical treatment, Lupron and other hormone therapies can cause side effects. Many of these side effects are symptoms of having very low testosterone levels.

Possible side effects of hormone therapies, such as Lupron, can include:

A person should discuss any side effects that they are experiencing with their healthcare team. If the side effects are severe, the doctor may recommend changing the dosage or trying a different treatment.

There are several treatment options for prostate cancer, including other LHRH agonists and hormone therapy.

Other LHRH agonists include:

  • goserelin (Zoladex)
  • triptorelin (Trelstar)
  • histrelin (Vantas)

Alternative hormone therapies include:

  • Orchiectomy. Also known as surgical castration, this is a surgical procedure to remove a person’s testicles. The testicles produce most of the body’s testosterone.
  • LHRH antagonists. These drugs work in a similar way to LHRH agonists, but they lower testosterone levels much more quickly. LHRH antagonists are a form of chemical castration, and doctors use them to treat people with advanced prostate cancer.
  • CYP17 inhibitors. In addition to the testicles, other cells in the body produce small amounts of testosterone. CYP17 inhibitors block these cells from making testosterone.
  • Anti-androgens. These drugs prevent testosterone from working in the body. Doctors usually prescribe anti-androgens in combination with other hormone therapies.

The first treatment for people with prostate cancer is often watchful waiting, where a doctor closely monitors a person to see how the disease progresses. Prostate cancer can progress very slowly, and some people never require treatment.

If a person’s cancer does progress to more advanced stages, treatment options can include:

  • radiation therapy
  • surgery
  • cryotherapy
  • chemotherapy
  • vaccine treatment

Doctors often use hormone therapies either in combination with or following one of these treatments.

As prostate cancer often progresses very slowly, the survival rates for this disease are generally high.

According to the ACS, the overall 5-year relative survival rate for prostate cancer is 98%. In other words, people with prostate cancer are 98% as likely to live for at least 5 years following diagnosis as those without the condition.

However, a person’s outlook can depend on how advanced the disease is when a doctor diagnoses them with prostate cancer.

For people with cancer that has not spread beyond the prostate or has only spread to nearby tissues or lymph nodes, the 5-year relative survival rate is nearly 100%. If cancer has spread to other areas of the body, such as the lungs, liver, or bones, the 5-year relative survival rate is 31%.

It is important to note that everyone’s outlook is different and that doctors have based these estimates on the data of men who received a diagnosis between 2011 and 2017.

Here are some questions people often ask about lupron.

How many Lupron shots do you need for prostate cancer?

This will depend on the individual’s diagnosis and why they need Lupron. Some people will have one injection every 4 weeks, others will have one every 24 weeks. A doctor will decide on the most suitable course of treatment.

Does Lupron cure prostate cancer?

Lupron cannot cure prostate cancer, but it can help reduce the risk of it progressing or returning.

What are the side effects of Lupron injections for prostate cancer?

Common adverse effects of Lupron overall include the following:

  • flushing
  • general pain
  • gastrointestinal problems
  • fluid retention, or edema
  • respiratory symptoms
  • urinary disorders

Over 10% of people using Lupron have reported these symptoms. However, the effects can vary according to the dose. A doctor can advise on specific adverse effects for the dose a person is taking.

How long can you have hormone injections for prostate cancer?

This will depend on the individual diagnosis and treatment plan. Factors that may affect the decision include disease progress and whether or not the person is experiencing side effects.

Lupron is a type of hormone therapy for prostate cancer. It works by lowering the amount of testosterone in a person’s body, which helps slow the growth of cancer cells.

Doctors often prescribe hormone therapies in combination with radiation therapy or following surgery. They administer Lupron by injecting it under a person’s skin, which they will do between once a month and once every 6 months.

Lupron lowers testosterone levels, so it can cause a range of side effects. Anyone experiencing severe or concerning symptoms may wish to discuss these with their doctor.