Neocote milk

It took my LG a week or so for her to drink it with no vanilla One thing that worked for us was nuby teether cleaning wipes (they're vanilla flavoured) and id rub it on the teat plastic part where her nose would be when she's drinking, and she would drink it this way! I'll try to find a link as they were a bit tricky to get hold of

https://uk.nuby.com/products/dummy-teether-wipes

Hopefully it works for you too, but if not, you have some sterilising wipes out of it haha 😂😅

Have you tried nesquick? Or depending on symptoms before mix with old formula an oz at a time

I've been so lucky my little boy just took to it without adding any vanilla! He won't eat food/purees but will drink this foul tasting formula lol

Banana Nesquik really helped my LB drink his allergy formula. We are able to change them when they trial him on new formulas quicker as well as he is used to the banana taste and doesn't get bothered by the change of formula taste. Obviously we will wean him off it over the next few weeks but it really helps! I hope your LO starts drinking more, I know it's so frustrating and worrying