Answer:
depends on what you're doing with it... are you in possession of it, manufacturing it, delivering it? Also, what schedule is the controlled substance? A schedule 1 substance is a much higher charge than a schedule 4. How much is there? Larger quantities mean higher charges, like with marijuana - in my state, possessing less than an ounce is only a violation, but possessing a large quantity is a felony. This brings me to the last variable, what state are you in? While federal laws are the same across the country, state laws do vary some so what is a violation in my state may be a misdemeanor in yours, or vice versa.
Soo... the answer depends on where you are, what it is, how much there is, and what you're doing with it. You can look it up in your state's revised statues, which are usually available online.