avent do a product for the nipples, its supposed to be for mothers who have inverted nipples who cant breast feed.
i used it about 3 years ago, half my nipple used to be inverted ..sounds weird i know and i still have it, but i have never needed it again since
it brings the nipple out and you wear it under your bra untill the effects sre permanenet, and that doesnt take long.
my nipples are now normally postioned andas soon as air goins anywhere near them, (cold or hot) they stick out, hence y in having probs with my nips getting stuck in the vacume hole lol.
i really would try it, it take just a few weeks, then if you want to make them bigger you can use the NB nipple enlarger, although if you use the avent product longer than you should it will make yr nips quite large
hope this help you xx