No. You shouldn't be concerned with the 3cc volume since you only need 1cc per injection. There isn't a specific ratio. It depends on how you mix it. It's quite simple. If you dillute 5,000 IUs HCG with 5ml (cc) solvent, the end result is 1,000 IUs per ml (cc). Divide the same 5,000 IUs with 10 ml (cc) and the end result is 500 IUs per ml (cc). Therefore, a large part depends on the concentration of HCG per ampoule or vial.
Jenetic