Test Overview

A toxicology test ("tox screen") checks for drugs or other chemicals in your blood, urine, or saliva. Drugs can be swallowed, inhaled, injected, or absorbed through the skin or a mucous membrane. In rare cases, a tox screen may check your stomach contents or sweat.

A tox screen may check for one certain drug or for up to 30 different drugs at once. These may include prescription medicines, nonprescription medicines (such as aspirin), vitamins, supplements, alcohol, and illegal drugs, such as cocaine and heroin.

Testing is often done on urine or saliva instead of blood. Many drugs will show up in a urine or saliva sample. And urine and saliva tests are usually easier to do than blood tests.