I started using these a week or so before delivery on the recommendation by my OB because my nipples were flat and one inverted also. They remedied the problem and my baby was able to get a good latch. The lactation consultants at the hospital were impressed with how well they worked for me. I continued to wear them while in the hospital after birth and in the first couple of weeks at home to keep the nipples out. After that I didn't really need them for the issue, but wore them from time to time when my nipples were sore.
Just got these to correct inverted nipples and so far they seem to work. My baby isn't here yet, but when he gets here these should help out a lot with nursing. Especially since I didn't have anything like it with my first 2 and it was really hard to start out nursing with inverted nipples.