NO The DOT does NOT do any testing, it is the company and only the company that does the testing. They ALL have to do a urine test by regulations and the hair test is their option and in addition to the urine testing. Hair testing is not part of their obligation as a carrier and has nothing to do with the regulations yet. some companies want to have that in place of the urine testing but the urine testing is a requirement and no way around it. IF you get into an accident and someone is killed, then you get a piss test by the local or state police, the DOT has nothing to do with this. If you are concerned, I would not be. unless the drug is on their illegal hit list, I wouldn't worry about it if you have a prescription and under doctor's care. By the way what is the drug?