A recent study found that the efficacy of letrozole when combined with oral contraceptives is more as compared to oral contraceptives alone in the treatment of endometriosis related pain. Also, the combined therapy is more tolerable.

In this study, 820 women participated who were suffering from pain symptoms related to endometriosis. The oral contraceptives used were desogestrel and ethinylestradiol. For six months, participants were treated randomly either with letrozole in combination with oral contraceptives or oral contraceptives only. The evaluation was based on the changes in pain symptoms during treatment, one month after treatment, and 6-month and 12-month follow-up. Adverse effects of both the treatments were recorded.

Results showed that the intensity of chronic pelvic pain sustained to reduce during treatment. The pain intensity was considerably reduced one month after the treatment and at 6-month follow-up, as depicted in the following table and graph:

Decrease in pain intensity during treatment and at 6-month follow-up 

Therefore, it was concluded that the letrozole when combined with oral contraceptives is promising for treating pain symptoms related to endometriosis.