A Cochrane review included 13 studies evaluating progestagens in the treatment of painful symptoms of endometriosis, with a total of 1551 subjects. .The progestagen medroxyprogesterone acetate (MPA) (100 mg daily) was more effective at reducing all symptoms up to 12 months of follow-up (MD -0.70, 95% CI -8.61 to -5.39; P < 0.00001) compared with placebo. However, there was more cases of acne and oedema in the MPA group compared with placebo. There was no evidence of a difference in objective efficacy between dydrogesterone and placebo, or between with depot administration of progestagens versus other treatments (low dose oral contraceptive or leuprolide acetate) for reduced symptoms. The depot progestagen group experienced significantly more adverse effects. There was no overall evidence of a benefit of oral progestagens over other medical treatment at six months of follow-up for self-reported efficacy. Amenorrhoea and bleeding were more frequently reported in the progestagen group compared with other treatment groups. There was no evidence of a benefit of anti-progestagens (gestrinone) compared with danazol. GnRH analogue (leuprorelin) was found to significantly improve dysmenorrhoea compared with gestrinone (MD 0.82, 95% CI 0.15 to 1.49; P = 0.02) although it was also associated with increased hot flushes (OR 0.20, 95% CI 0.06 to -0.63; P = 0.006).
including 14 studies with a total of 380 subjects was abstracted in DARE. 4 of the studies were RCTs, 1 was quasi-experimental, and 9 were non-comparative studies. Combining the two doses of progestin one RCT showed that dydrogesterone was no more effective than placebo in reducing pelvic pain during treatment (OR 0.8, 95% CI 0.2 to 3.3) and after 1 year of follow-up (OR 1.2, 95% CI 0.2 to 5.6). For the other four randomised trials of progestin vs. danazol, danazol and oral contraceptive or goserelin, the treatment effects were equivalent (OR 1.1). The pooled frequency of pelvic pain at the end of follow-up was 50%. The conception rate after treatment in 8 studies ranged from 36% to 50%."?>Comment: The quality of evidence is downgraded by inconsistency (heterogeneity in interventions and outcomes) and by imprecise results (limited study size for each comparison).