By "elastic" nipples, we take it to mean very stretchy skin. Our pump does not pull the nipple into the breast shield the way that other pumps do into their flanges. In the research we have conducted, while we did have moms with stretchy skin, none experienced their nipples touching the end of the breast shield during pumping. That said, everyone's body is different, and we cannot guarantee your body will respond in the same way or that this pump will work for you. Because breast pumps are medical devices, we cannot issue a refund solely because of a customer's nipple elasticity.