Hormone Therapy

A common class of medications used to help manage the symptoms of endometriosis are hormone-altering drugs. These medications, often called hormone therapy, impact the levels of certain hormones in the body. Many hormone therapies suppress ovarian function in one way or another. This can prevent a woman from ovulating (the process by which she releases an egg each month). Ovulation can lead to a spike in various hormones, such as estrogen and progestin. These hormones, and their high levels, are often linked to the growth, thickening, and break down of endometriosis lesions. By suppressing ovarian function and ovulation, the levels of these hormones can be stabilized, potentially shrinking endometriosis lesions and reducing pain.

Combination contraceptives

Combination contraceptives are medications intended for use by women who are sexually active but who do not wish to become pregnant. Combination contraceptives are often used off-label to treat other female reproductive system-related issues such as painful periods, endometriosis-related pelvic pain, menstrual migraines, PMS (premenstrual syndrome), and menstrual cycle irregularities. Combination contraceptives may also be used to improve bone mineral density or to treat acne. Combination contraceptives contain a synthetic estrogen and a synthetic progestin, two hormones that influence the female reproductive system and suppress ovarian function, potentially impacting endometriosis lesion growth.

Because they contain estrogen, these medications carry an increased risk of developing blood clots. Additionally, they may increase a woman’s risk of developing bleeding irregularities or impaired liver functioning. Combination contraceptives make the body think that it is already pregnant, and stops it from ovulating (the process by which the ovaries release an egg each month). This suppression of ovarian function helps stabilize natural hormone levels in the body, suppressing endometriosis lesion growth. Combination contraceptives include birth control pills, as well as the vaginal ring (NuvaRing) and the skin patch (Ortho Evra, Xulane) contraceptives.1,2

Progestin-only contraceptives

Progestin-only contraceptives are medications intended for use by women who are sexually active but who do not wish to become pregnant and who cannot, or should not, take estrogen-containing medications. Progestin-only contraceptives suppress ovarian function, and are often used off-label to treat the same female reproductive system-related issues as combination contraceptives. Progestin-only contraceptives can increase the risk of developing ovarian cysts, ectopic pregnancy (pregnancy outside of the womb), and issues with liver functioning. Additionally, progestin-only medications may increase the risk of developing certain cancers such as breast cancer. Progestin-only contraceptives include progestin-only birth control pills, as well as the hormonal IUD (intrauterine device, Mirena), the birth control arm implant (Nexplanon), and the progestin injection (also referred to as the birth control shot, Depo-Provera).1-3

Gn-RH agonists

Gonadotropin-releasing hormone agonists (Gn-RH agonists) are medications that suppress ovarian function and reduce levels of estrogen and other hormones in the body. Gn-RH agonists can be used by women to reduce endometriosis-related pain. They can also be used to prevent the recurrence or progression of certain types of cancer, or as palliative treatment option for several types of breast or prostate cancers. This means that they are intended to help reduce quality of life-impacting symptoms. When women take Gn-RH agonists, the level of estrogen in their body is decreased to a menopausal-like state. This can lead to menopausal-like side effects such as hot flashes, vaginal dryness, and a decreased libido (interest in sex). Gn-RH agonists can be administered as pills, injections, or nasal sprays.

In order to lessen the severity or presence of some of these symptoms, Gn-RH agonists taken for endometriosis pain are often accompanied by an add-back therapy. An add-back therapy is often an orally administered medication that is taken daily and contains low amounts of estrogen and progestin, or progestin alone. Long-term use of Gn-RH agonists is typically not recommended, as Gn-RH agonists may increase the risk of developing cardiovascular complications as well as severely decreasing bone mineral density. Using an add-back therapy may also help prevent significant bone mineral density loss.2,4

Danocrine (danazol)

Danocrine (danazol) is a medication indicated for women with endometriosis to treat endometriosis-related pain. Danazol is a synthetic steroid that interacts with complex hormonal pathways. Ultimately, Danocrine suppresses ovarian function, and the pituitary-ovarian axis, which decreases the amount of estrogen in the body, among other outcomes. This decrease in estrogen can shrink endometriosis lesions, as well as potentially prevent them from thickening and breaking down, decreasing endometriosis-related pain. In addition to this, Danocrine also acts on androgen receptors, increasing male hormone levels in the body. This can lead to distressing side effects for women, such as decreased breast size and experiencing deepening of the voice.2,5

Written by: Casey Hribar | Last reviewed: June 2018
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