What is a menstrual cup? The Be You Menstrual Cup can be worn during your period for up to 12 hours at a time. With the correct care, it will last for ten years, therefore cutting down on waste and monthly cost. The Menstrual Cup is made with 100% soft, medical grade silicone. With no hazardous chemicals, BPA, Latex, or Dye. Available in 2 sizes. For best results use with Menstrual Cup Foaming Cleanser. Which size should I choose? We recommend using the Large cup if you are over the age of 25 or if you have given birth vaginally.