The menstrual cup is first folded or pinched and then inserted into the vagina. It will normally unfold automatically and create a light seal against the cervix. In some cases, the user may need to twist the cup or flex the vaginal muscles to ensure the cup is fully open. If correctly inserted, the cup shouldn’t leak or cause any discomfort. The stem should be completely inside the vagina. There are various folding techniques for insertion; common folds include the c-fold, as well as the punch-down fold.
If lubrication is necessary for insertion, it should be water-based, as silicone lubricant can be damaging to the silicone.