Has anyone used synarel (nafarelin) to treat endometriosis?

Long time. Yes, i used it to treat patients occasionally in the early-mid 1990s, as did many other specialists. It was fairly effective but cumbersome to use. I've not used it in many years, and it's overall popularity has faded significantly.
GnRh agonists. Like Lupron , synarel (nafarelin) will block the surge of fsh responsible for ovarian estrogen release decreasing these stimulation of endometrial tissue.