When you take cocaine, it quickly absorbs into your blood plasma.
Enzymes in the blood and the liver metabolize cocaine, transforming it into various metabolites, including benzoylecgonine which leaves the body in your urine. Your blood also deposits cocaine and its metabolites in your hair as it grows.
Drug tests can detect cocaine and its metabolites in your blood plasma, urine, and hair.
Blood and Urine Tests
The length of time that a substance is detectable in your blood or urine depends on its half-life. The half-life of a substance is the amount of time it takes for the concentration of the drug to reduce by half.
The average half-life of cocaine in blood plasma is around one and a half hours. You can usually test positive in a blood test for roughly two days after last use.
While the average half-life of cocaine in urine is about four and a half hours, the half-life of its metabolites may be much longer. The metabolite benzoylecgonine typically shows up in a urine test for forty-eight to ninety-six hours after use.
Research suggests that repeated use of cocaine results in a buildup in your body. This may increase the amount of time that cocaine and its metabolites stay in your system. A heavy user may test positive in a urine test up to two weeks after last use.
Hair Follicle Test
Hair follicle tests aim to detect cocaine use within the past three months, although they can often detect the presence of cocaine past this. Cocaine and its metabolites are detected via blood deposits in your hair. However, your environment may also deposit cocaine on your hair, which may lead to false positives in follicle tests.