The advantage of the MENLO device is that it can treat excessive menstruation or dysmenorrhea, but the disadvantage is that it is prone to cause irregular vaginal bleeding and symptoms such as dribbling menstruation. The MMS is a slow-release contraceptive that is added to the regular birth control device, and is especially suited for women who have heavy, irregular or painful menstrual periods. The birth control device can be released slowly in the uterine cavity, thus regulating the thickness of the uterine lining, regulating the amount of menstruation as well as being able to treat dysmenorrhea. However, if you have a regular menstrual cycle, it is not recommended to use the MENLO device. Because of the normal endometrial cycle shedding, once affected by the sex hormones in the birth control device, there may be excessive endometrial hyperplasia or secretion, irregular vaginal bleeding or even amenorrhea symptoms.