Endometriosis is a chronic benign disease that affects women of reproductive 
age. Medical therapy is often the first line of management for women with 
endometriosis in order to ameliorate symptoms or to prevent post-surgical 
disease recurrence. Currently, there are several medical options for the 
management of patients with endometriosis. Non-steroidal anti-inflammatory drugs 
(NSAIDs) are widely used in the treatment of chronic inflammatory conditions, 
being efficacious in relieving primary dysmenorrhea. Combined oral 
contraceptives (COCs) and progestins, available for multiple routes of 
administration, are effective first-line hormonal options. In fact, several 
randomized controlled trials (RCTs) demonstrated that they succeed in improving 
pain symptoms in the majority of patients, are well tolerated and not expensive. 
Second-line therapy is represented by gonadotropin-releasing hormone (GnRH) 
agonists. Even if these drugs are efficacious in treating women not responding 
to COCs or progestins, they are not orally available and have a less favorable 
tolerability profile (needing an appropriate add-back therapy). The use of 
danazol is limited by the large availability of other better-tolerated hormonal 
drugs. Because few data are available on long-term efficacy and safety of 
aromatase inhibitors they should be administered only in women with symptoms 
refractory to other conventional therapies in a clinical research setting. 
Promising preliminary data have emerged from multicenter Phase III trials on 
elagolix, a new oral GnRH antagonist but non-inferiority RCT data are required 
to compare elagolix with first-line therapies for endometriosis.