Hormone Therapy for Endometriosis

Hormone therapy is a common treatment for managing the symptoms of endometriosis. Hormone therapy is a first-line treatment for endometriosis because it is low-risk, has minimal side effects, and helps relieve endometriosis symptoms. It involves a range of medicines that affect hormone levels in the body, each working on different hormones and in various ways.¹

No one hormone therapy works better than the other for endometriosis. What works for one person may not work for another. Hormone therapy should take an individualized approach.¹

How does hormone therapy work?

Many hormone therapies work by preventing ovulation, the release of an egg from the ovary. Ovulation can trigger spikes in hormones like estrogen and progesterone, which are often associated with the growth, thickening, and breakdown of endometriosis lesions.¹

By preventing ovulation, these hormone levels are stabilized. This may lead to the shrinking of endometriosis lesions and reduced pain.¹

What are the active ingredients of hormone therapy?

The active ingredients of hormone therapy vary by type of prescription and brand.

Examples of hormone therapy for endometriosis

There are many different types of hormone therapy. Examples of hormone therapies include:^1-4

• Birth control with estrogen and progestin – These might be pills, shots, patches, or rings that contain the hormones estrogen and progestin. They can help cause lighter and shorter periods.
• Progestin-only birth control – Progestin treatments can stop your period and the growth of endometriosis. These include implants, shots, pills, or intrauterine devices (IUDs).
• Gonadotropin-releasing hormone (Gn-RH) agonists and antagonists – These medicines stop your period and lower estrogen levels in the body.
• Danazol (Danocrine®) – This medicine stops the hormones that cause you to have a period.

Birth control with estrogen and progestin

Combination birth control contains man-made estrogen and progesterone. Both of these hormones affect how the reproductive system works by preventing the ovaries from working. This may reduce the growth of endometriosis lesions, which may lessen pain.^1,2

Examples include:^1,2

• Combination birth control pills
• Vaginal ring (NuvaRing®)
• Skin patch (Ortho Evra™, Xulane®)

Progestin-only birth control

Progestin is a man-made form of the hormone progesterone. Progestin-only birth control may be taken by people who cannot take estrogen. Progestin is given by pill, injection, or intrauterine device (IUD).^1-3

These medicines prevent the ovaries from working. This reduces menstrual flow and limits the growth of the uterus lining. This reduces the size of endometriosis lesions, which may help reduce pain.^1-3

Types of progestin-only treatments include:^1-3

• Progestin-only birth control pills
• Arm implant (Nexplanon®)
• IUD (Mirena®)
• Birth control shot (Depo-Provera®)

Gn-RH agonists

Gn-RH agonists reduce estrogen and other hormone levels to a menopause-like state. This may lead to less endometriosis pain. It is taken as a pill, nasal spray, or injection.^1,2

Examples include:¹

• Nafarelin (Synarel®)
• Leuprolide (Eligard®)
• Buserelin (Suprefact®)
• Goserelin (Zoladex®)
• Triptorelin (Triptodur®)

Gn-RH antagonists

Gn-RH antagonists also suppress the hormones that stimulate the ovaries but work through a different mechanism than Gn-RH agonists. They offer the benefit of potentially fewer side effects.^1,2

Examples of Gn-RH antagonists are:¹

• Elagolix (Orilissa®)
• Relugolix (Orgovyx®)
• Danazol (Danocrine®)

Danazol (Danocrine®) is another drug used to treat endometriosis pain. It is a man-made steroid that has a complex action on hormones. Ultimately, it stops the ovaries from working and decreases estrogen.^1,2,4

This decrease in estrogen can shrink endometriosis lesions. It may also prevent these from thickening and breaking down, which decreases pain.^1,2,4

What are the possible side effects?

Side effects vary depending on the specific drug you are taking.

Combination birth control has the following potential side effects:^1-3

• Lighter, shorter, and more regular periods
• No periods at all
• Weight gain
• Bloating
• Increased risk of blood clots, certain cancers, and bleeding issues

Progestin-only birth control has the following potential side effects:^1-3

• Irregular or absent periods
• Weight gain
• Depression
• Ovarian cysts
• Certain cancers
• Liver problems
• An increased risk of ectopic pregnancy

Gn-RH agonists and antagonists have the following potential side effects:^1,2

• Headaches
• Nausea
• Sleep problems
• Hot flashes
• Fatigue
• Vaginal dryness
• Joint and muscle stiffness
• Decreased libido
• Depression
• Bone density loss

Gn-RH agonists and antagonists generally cannot be taken long-term. Most doctors recommend they be taken for only 6 months at a time because they may cause heart complications and osteoporosis.^1,2

Danazol has the following potential side effects:^1,2,4

• Irregular or absent periods
• Oily skin
• Weight gain
• Muscle cramps
• Breast changes
• Headaches
• Dizziness
• Hot flashes
• Voice deepening

These are not all the possible side effects of these drugs. Talk to your doctor about what to expect or if you are concerned about any changes while using hormone therapy.

Before beginning treatment for endometriosis, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you take. This includes over-the-counter drugs.