No Peeks fit differently on people- it depends on the shape of the bust. I think that you may have bought the wrong size (M). You need to try size (S) or perhaps go back to the nipple covers that used before.
Mickey from Hephzibah, Ga. Richmond
If the consumer was looking for a pad to ad cup size or volume, this is not what the no peeks are meant to do. No peeks are for modesty and smoothing.