This randomized double-blind study, with 24-week treatment and 24-week 
posttreatment periods, evaluated the effects of elagolix (150 mg every day, 75 
mg twice a day) versus subcutaneous depot medroxyprogesterone acetate (DMPA-SC) 
on bone mineral density (BMD), in women with endometriosis-associated pain (n = 
252). All treatments induced minimal mean changes from baseline in BMD at week 
24 (elagolix 150 mg: -0.11%/-0.47%, elagolix 75 mg: -1.29%/-1.2%, and DMPA-SC: 
0.99%/-1.29% in the spine and total hip, respectively), with similar or less 
changes at week 48 (posttreatment). Elagolix was associated with improvements in 
endometriosis-associated pain, assessed with composite pelvic signs and symptoms 
score (CPSSS) and visual analogue scale, including statistical noninferiority to 
DMPA-SC in dysmenorrhea and nonmenstrual pelvic pain components of the CPSSS. 
The most common adverse events (AEs) in elagolix groups were headache, nausea, 
and nasopharyngitis, whereas the most common AEs in the DMPA-SC group were 
headache, nausea, upper respiratory tract infection, and mood swings. This study 
showed that similar to DMPA-SC, elagolix treatment had minimal impact on BMD 
over a 24-week period and demonstrated similar efficacy on 
endometriosis-associated pain.