From your other threads i can say without a shadow of a doubt you do not need and are nowhere near ready to be doing steroids. As i recall you are about 5'7", 140-150lbs, and 17 years old? I also remember you saying that you eat less than 1000 calories a day?
You don't need anabolics, and for your age and body size i would go so far as to say taking them would present a huge risk to your health. And we're not talking in a "you'll be a bit sick for a while" way we're talking in a "you might end up DEAD" way. If your friends are suggesting steroids to you, they either know about as much as you do on the subject, or are incredibly bad friends.
If you are not gaining weight or losing fat or whatever you want to accomplish with drugs, its because your diet and training are wrong. At your age your natural test levels are as high as they will EVER be in your life. All you need to do is learn to eat properly, learn to train properly, and put the damn effort in.
Even if you do take the steroids, i guarantee you will not gain. Just because you're taking an anabolic compound the energy to build muscle needs to come from FOOD, and the stimulus for muscle growth needs to come from TRAINING. All these substances do is increase the rate at which your body can build muscle, and improve your recovery rate. If you arent making progress without them, you wont make progress on them.
They aren't magic, and taking them right now would not only be a waste of money, but you could very well damage your body beyond repair. What you need is a lot of food and some good training. Put the effort into educating yourself and then carrying out what you've learned. It's hard, its difficult, but something that's worth having is worth fighting for.