I am aboy of 18 yr and my height is168 cm . i'm doing exercises to grow . what supplement should i intake ......to rapid grow...to 2to3inch tall?

Teen nutrition: There is really nothing you can do to change your growth speed. Your height is essentially programmed by the combination of your parents' genes, and "supplements" and exercise won't change it. But the good news is that eating a healthy, balanced diet which is low in simple sugars and saturated fats along with healthy daily exercise will allow your body to grow to its full potential.