hey bro's im 18. im on a cutting diet and i heard that injecting b-12 helps metabolism and break down of protein. i was wondering if someone can tell me about this. i never used A.S. so i dont know much about syringes but b-12 is a vit. so it cant be bad for u. I just mainly need to know what size syringe to get and if i can get a liguid b12 from gnc or sumtin.