to be honest, if you are 19, you are too young to be concerned with 1-androstenediol. Yes, there is a risk that you may stunt your growth, but that is only if you are a late bloomer. Yaou may damage your endocrine system, as you are still semi-young. I would follow the directions and wait untill your 21.
But, if you insist, 300mg a day for 4 weeks for a first cycle. Then run 6-oxo for 3-4 weeks post-cycle.
And yes, your balls would probably shrink.
If you decide to do it, which I think you shouldn't, DO NOT EXCEED 300mg for the first cycle.
Good luck