Yes, cannabis can show up on drug tests. Drug tests typically look for the presence of THC, the psychoactive component in cannabis, in a person’s system. THC can be detected in urine, blood, saliva, and hair follicle tests. Urine tests are the most common type of drug test used to detect cannabis use. THC can be detected in urine for up to 30 days after last use, depending on the frequency and amount of cannabis consumed. Blood tests can detect THC for up to a few days after use, while saliva tests can detect THC for a few hours to a day after use. Hair follicle tests can detect THC for up to 90 days after use.