I have Soothies from the hospital, and then a couple of MAM glow in the dark ones I got at my shower. The MAM say 6+ months - any truth to that?

A friend gave me her extra Soothies because she felt they DID confuse her son a bit in the beginning. So is it better to give a pacifier that is more like a nipple or less? And should I go shop for ones for a newborn/4 week old +?

TIA as always