They are far worse than steroids. Most of the prohormone formulas were reject steroid formulas from the 50's. They weren't used for a reason. Then guys like Pat Arnold pushed them on the market and made it seem like they were completely safe. And sometimes they aren't even that, just sugar pills.
Either way at your age you don't need steroids, prohormones, or any of that stuff. Your body is FULL of test right now.
Do me a favor, try this for three months before making any decisions, and I mean really stick with it, I bet you will see gains.
Monday: Squat, Bent Over Row, Chins
Wednesday: Bench Press, Clean and Press
Friday: Deadlifts, Dips, Curl
You can throw in some extended torso work on day two (bar hangs, hypers, crunch etc) Always warm up, do 4-5 sets for each exercise, pyramid up the weight with each set, and add weight or reps each week. Make those lil 2.5 plates your friend.
Nutrion: Lot's of whole milk, whole eggs, pb sands, lot's of meat, veggies, plenty of carbs (oats, potatos, brown rice, whole wheat bread). Eat fruits, nuts, etc too. Take a multi every day. Post workout drink a shake with creatine (fuck all those fancy brands, get plain old creatine. save your money for the real food), a couple scoops of whey, and some simple sugar (gateraid, even a coke). Drink another shake before bed mixed with whole milk.
All of this is a general outline, if you need more detailed help search around, ask, PM me, etc. But I won't lie to you, at your age you will get better results off this than any steroid of prohormone cycle.