I'm ashish i'm 20 years old. i wanted to know how can i grow my height. i'm 5.5 ft. is there any medicine or injection to grow fast. ?

No: There is nothing that will help you grow taller at 20 years old. The growth zones of your bones have already calcified and are not capable of growing longer.

Unlikely to happen: The growth centers of your bones determine how tall you can grow.Most growth centers will close at 16-19 years of age in males. After that happens, you can not grow taller. If your growth centers were open, a balanced diet/rest ; healthy physical activity would support good growth.There are no special diets,meds or exercises that make you taller.