There are reports that DMPA if used for a long time (say 3 to 5 years) may thin out your bones and make them brittle (osteoporosis). You have to see how much DMPA is helping you remain symptom free from endometriosis. If it is really helping you, then you may continue it for another couple of years. Take a bone density test every 6 months to a year. DMPA also suppresses symptoms of adenomyosis, but I doubt that the latter could be diagnosed after a D&C.