Kind of same answer as PP, just a different method: I use continuous birth control pills (no placebo pills) to skip my periods completely. Think the docs said even just using birth control pills in general can cut down on growth of endometriosis lesions, but better still not to have those painful periods at all! (And PS, I'm 43, but doctors say that's not actually too old. I hesitated to ask for the Pill after 35 because I thought that was supposed to be bad, but now kicking myself for waiting because apparently the after-35 thing just isn't true.)