Hi,im a 20 boy and im 175 cm. i searched everywhere but the answers was different.i want to know if i take l-arginine supplements can i become taller?

No: At a listed age of 20, your growth centers are likely closed and no further linear growth would be expected. An x-ray of your wrist and hand could be reviewed for open growth centers, but if they show closure you are finished growing taller. If open, a balanced diet, proper rest and regular exercise will support proper growth. Diet supplements or hormone injections only help those with deficiency

Noooooo!: Your bones (the long ones) grow from the ends. That usually stops by age 16 in girls and 18 in boys. If the growth plates have fused at the ends, that's it. Human growth hormone (HGH) not L-arginine (an amino acid) is the only thing that can work. People who have that happen to them look like Frankenstein's monster in the movies. Read the "Serenity Prayer" by Reinhold Niebuhr.