Much research has gone into developing medications that can be used to alleviate 
endometriosis-associated symptoms. In addition to already established 
medications, a new GnRH antagonist, elagolix, is in development. The novelty of 
this drug compared to other GnRH antagonists, is its nonpeptide structure, 
allowing it to be administered orally. Areas covered: We analyzed several Phase 
I, II and III clinical trials that have evaluated the safety and efficacy of 
this new medication. Expert opinion: Since many medications have been put on the 
market and have gained popularity for the treatment of endometriosis-associated 
symptoms, the demonstration of equality or superiority of effect, tolerability, 
as well as patient compliance should be assessed when introducing a new drug. 
While elagolix may have an advantage over established GnRH agonists, in that it 
does not lead to a 'flare-up' effect, it too, takes a toll on bone mineral 
density. Nevertheless, studies have shown that this new oral GnRH antagonist is 
well tolerated, and the side effects have been described as 'mild or moderate'. 
However, in order to examine whether elagolix can compete with or even surpass 
established gold-standard medical treatments in this field, further studies that 
directly compare elagolix to said treatments, might be necessary.