As long as GH is being produced, the growth plates will continue to produce new bone and the person will grow taller. When the growth plates are fused, which can be seen plainly on an X-ray, it’s game over for growing taller. In these cases, the bone must be set with extra care to avoid problems with future bone growth. Simply stated, if one or both of your parents are taller than most, all else being approximately equal, you’re likely to be taller than most. Our only physical guarantee as adults is growing outward if we don’t control our habits, rather than any guarantee of growing upward.