Hormonal Treatments for Endometriosis

Women who are diagnosed with endometriosis are often prescribed hormonal treatments to help manage their condition. But what do these drugs really do and are they effective? It’s important for women with endometriosis to be as informed as possible about the treatment options available. In this article, we will explore some of the more common drugs that are prescribed for endometriosis.

The oral contraceptive pill (OCP)

The OCP is widely used to treat endometriosis related pain. The aim of using the pill is to decrease the activity of lesions which are dependent on hormones that are believed to be a key driver of the disease and symptoms.¹ The combined oral contraceptive pill has been observed to lighten periods and suppress the growth of endometriosis lesions.²

However, it should be noted that the existing research on the combined oral contraceptive pill as a treatment for endometriosis is limited. In fact, a large 2018 review assessing all of the studies on the oral contraceptive pill determined there is very little evidence to support its use for reducing endometriosis related pain.¹

Synthetic progesterone or progestins

These may be used instead of the combined oral contraceptive pill. Progestins can be helpful for managing endometriosis because they help to thin the endometrium lining, suppress ovulation, reduce circulating levels of estrogen and can decrease inflammation.³

Examples of synthetic progesterone medications include:

• Norethindrone acetate
• Norethisterone
• Dienogest
• Medroxyprogesterone acetate
• Intrauterine systems with levonorgestrel (such as Mirena)

Micronised progesterone is natural progesterone (also known as a body identical hormone) and is an alternative to synthetic progestins. The brand name commonly used is Prometrium. However, using progesterone for suppression of endometriosis requires high doses which lowers estrogen, resulting in bone loss if used long term.

Androgens

One example of androgenic hormones is Danazol. Androgens are responsible for the development of male characteristics such as facial hair. While Danazol can be effective by suppressing the growth of endometriosis, it is less favorable due to its unwanted side effects such as increased body hair and acne.

Gonadotropin-releasing hormone (GnRH)

GnRH agonists and antagonists are modified versions of gonadotrophin-releasing hormone, a naturally occurring hormone that suppresses the menstrual cycle. GnRH medications are considered a second-line treatment which dramatically reduce estrogen.³ Some examples of GnRH medicines are:

• Synarel (generic name naferelin)
• Zoladex (generic name goserelin)
• Depot (generic name leuprolide)
• Lupron (generic name leuprolide)

GnRH agonists and antagonists can be very helpful for managing endometriosis symptoms. However, they can also cause menopause symptoms and their long-term use is linked with decreased bone mineral density.³

Aromatase inhibitors

These are used for the treatment of endometriosis and its symptoms because the endometriotic tissue over-expresses aromatase, which is an enzyme within the tissue that can increase the production of estrogen. This is important to note because endometriosis is an estrogen-dependent condition.^4,5

Summary

Endometriosis is a chronic disease and hormone therapy can only be used for symptom control, therefore cannot be considered a cure.¹

It’s also important to remember that medications are not risk free and the side-effects can vary greatly depending on the drug. If your doctor wishes to prescribe medications, ask them about the potential risks and side-effects so you can make an informed decision.