I originally purchased this in my usual retailer size 6 (vanity size lol), and was nervous that the neck would be tight, based on the other reviews. however, once i tried it on i realized that in my usual size the body was a little too wide and didn't create any shape. i ended up exchanging for and keeping a size 4 and it fits much better in the body and i did not have a problem with any tightness in the neck in either size. for reference i'm 5'7", 36dd 135lbs.

i would say this items runs true