"Menstrual cup are better than tampoons in two ways, you can say. First the way they act is collection rather than absorption. So when they are just collecting the menstrual fluid, they are just collecting the menstrual fluid, and not absorbing the normal vaginal fluid, so they are less chances of causing pain, irritation and dryness when you are using a menstrual cup. The second thing is there is less chances of toxic shock syndrome that is known with time with tampons for a long time. That is one thing; the second part is can the menstrual cup cause infection? Anything that is foreign body and that is entering the vain can cause infection but if we follow the hygiene and if we use soap before inserting the foreign body, that is the menstrual cup the chances of having infections due to menstrual cup are almost negligible. They have been reports of causing urinary tract infections , repeatedly in patients of menstrual cup. There has been logical reason behind it, sometimes when you use a cup size bigger than you require, it keeps on pressing the urethra permanently causing a retention of urine in the bladder and causing repeated infection. In such a case most of the time the problem is resolved by using a smaller type of cup"