High protein drinks are good for growth in general. I don’t think there’s anything that exists solely for penis growth. Eat a gram or two of protein per pound of body weight per day.
Hey, you know something? Does anyone take creatine? When you take creatine, it’s in your blood right? From there it goes into your muscles, but there’s an elevated level of creatine in the blood still, right? If so, wouldn’t using creatine give you a harder hard-on? I’ll have to see about that…