Seven RCTs (1,096 participants) were included in the review. Three trials scored the maximum 5 on the Jadad scale, three trials scored 3 and one trial scored 2. The study sample size ranged from 41 to 300 women.
Progestogen versus GnRHa: There was no statistically significant difference in relieving endometriosis-associated pain (three trials). GnRHa appeared to cause more bone mineral density loss than progestogens. Progestogens were associated with a higher incidence of spotting.
Implanon versus DMPA: There was no statistically significant difference in relieving endometriosis-associated pain (two trials). Patients in both treatment groups experienced similar side-effects such as acne, weight gain, hair loss, and breast tenderness.
Combined oral contraceptive pills versus control versus progestogen: There was no statistically significant difference in relieving endometriosis-associated pain (three trials). Progestogen was associated with more bloating and spotting than combined oral contraceptives.