It works in over 80% situations with regular treatment for up to 6 months. And follow up scan, for size of endometrial thickness. The menses diary is also kept. If it fails, there are other options like a mirena/ conservative treatments like TCRE and endometrial ablation by laser, current or heat- before going for hysterectomy. These have their own risks and benefits. Also other medications like danazol, tranexamic acid and even mefanamic acid are available to reduce blood loss. Anaemia medicines can be taken alongside for quicker recovery.