Some drugs are excreted faster than others
Because drugs need to be converted into soluble metabolites before they can be excreted, the speed with which this can occur depends largely on what sort of metabolites are created and how concentrated these are. LSD, for instance, is typically taken in very small doses, rarely exceeding 100 to 200 micrograms, which means only tiny amounts of metabolites are likely to be detectable in a user’s system.
Furthermore, most metabolites of LSD tend to pass out of the body very quickly. The main one, for example, is 2-oxo-3-hydroxy LSD, which is completely undetectable in the bloodstream and only present in very small quantities in urine, but only for a few days.
So how long does each drug actually stay in your system for?
The most common types of drug tests will look for drug metabolites in the blood, urine, and hair, the latter of which can become contaminated with traces of drugs as blood washes over the follicle. So without further ado, here’s how long some common illegal drugs remain detectable for:
Cannabis: 7 to 30 days in urine; 90 days in hair; 14 days in blood
Cocaine: 3 to 4 days in urine; 90 days in hair; a day or two in blood
Heroin: 3 to 4 days in urine; 90 days in hair; about half a day in blood
LSD: Up to 3 days in urine; 3 days in hair; less than five hours in blood
MDMA: 3 to 4 days in urine; 90 days in hair; a day or two in blood
Methamphetamine: 3 to 6 days in urine; 90 days in hair; up to three days in blood
Image: Urine and blood are the most commonly tested body fluids for drugs. JPC-PROD/Shutterstock