Several medications are used to treat endometriosis. All of these medications suppress ovulation and cause a hypoestrogenic state. Understandably, suppressing ovulation also prevents pregnancy from occurring so medical therapy is not appropriate in patients actively seeking fertility. In patients who are not trying to conceive, medical treatment of endometriosis can be very beneficial and relieve symptoms of dysmenorrhea and pelvic pain.

One common medical treatment is to prescribe the combination oral contraceptive pill. Although each of these daily pills contains estrogen, the progestin (progesterone- like component) in the pill overrides the estrogen effect, resulting in suppression of endometriotic lesions. Oral contraceptive pills are effective in 30% to 60% of patients with endometriosis-related pain.

Many physicians prescribe gonadotropin-releasing hormone (GnRH) analogs (such as Lupron), which reduce estrogen levels to postmenopausal levels for their patients with endometriosis. These medications suppress estrogen production, prevent ovulation, and cause atrophy of the endometriosis in 70% to 90% patients. Unfortunately, GnRH analogs are expensive and must be given as injections either once a month or every 3 months. GnRH agonists can cause side effects including headaches, hot flashes, moodiness, insomnia, and vaginal dryness. To counteract these side effects experienced by many patients treated with GnRH agonists, physicians often prescribe oral contraceptive pills or supplemental progestin therapy (such as norethindrone) along with the GnRH analogs. This combined therapy may allow for improved treatment acceptance and alleviate many side effects associated with the use of the GnRH analogs as single therapy. Patients tolerate this combination very well and achieve maximal benefits in suppressing the disease and its symptoms.

As noted previously, medical therapy is not indicated for patients with endometriosis who are actively trying to conceive, since all of these treatments will suppress ovulation. Instead, for these patients, the goal should be to promptly establish pregnancy before the endometriosis causes any further damage to the reproductive organs. Generally, these women should seek treatment from a fertility expert to maximize their chances for successful pregnancy.