Hormones, food, and growing is simple.
If you're not gaining from lifting and food, you can't gain from steroids (or from increasing your dosages). It's like this:
Your body = new building being built
Nutrition = bricks
Hormones = workers
Now you already have some workers, but not enough bricks or you'd be growing. So if you bring on more workers, why would they help since you're already short on bricks?