You’ve seen it on reality shows and sometimes even on your favorite celebrities—cosmetic procedures that go too far or patients that go under the knife (or needle) one too many times. When faced with the results of too much pinching, tweaking or filling, one has to wonder, “Why would a doctor allow that?” But many doctors do say no and have no problem doing so. Perhaps the 400-cc breast implant your friend got won’t work for your body, or your frown lines are better treated with a filler than a facelift, there are many instances when a doctor can and will say no in order to achieve the best possible outcome. We talked to a few top doctors to find out how and when they know they won’t be able to fulfill a patient’s wishes.