Students at Clemson speak positively of the drug scene. Besides the heavy alcohol consumption, drugs are only available if you're looking for them. Those people who do drugs don't tend to pressure those who don't.
Whether you see college as a time of experimentation or as four years with your head in your books, drugs will only influence your life as much as you let them. Heavy drug usage such as cocaine and heroin is rather scarce, which is a good sign for a school dedicated to becoming a top public university. At Clemson, you will find that the students committed to academic success avoid drugs entirely.