Agreed that 17 is too young. You say you've been training on/off for about a year? That's a good start, but it's not very long. Hit it a lot harder and be more consistent. Workout at least another 2 or 3 years NON STOP (with occasional one or two week breaks as needed). After then think about juice again. For all you know you might be doing SO good naturally that you won't even want to juice.

And those friends of yours, if they aren't very careful, and just keep juicing up at really high amounts, won't be where you will be at the age of 25 or so. They all mess up their growth and natural process, you'll see that in the long run you can hold more mass and all that. Of course it all depends on genetics too, and not everyone can be Ronnie