I used shields for a couple of weeks out of sheer desperation as my nipples were in agony with DS's shallow latch due to a tongue tie. We had the tie snipped but it still took a bit of time for the latch to be perfect and for my nipples to heal. IN the end the shields were rubbing on my nipples and making them worse so I ditched them and by then DS was latching well and the pain reduced. I had no issues with supply. HTH