Perhaps it isn't noticable to anyone but you, but a sagging neck and jowls can really do a number on your self confidence. The good news is that there is a quick fix - and no, it doesn't require a trip to the plastic surgeon. Women, especially those over 40, are raving about the ShapeShift V-Line Jaw Defining Serum by SickScience Labs, swearing that it creates a noticeable difference in just a couple of weeks.