Eli5 How far back do drug tests check?

Question

I don’t know how to phrase the title, I’m sorry.
ANYWAYS, do drug tests check if you’ve EVER done drugs, or or in a specific amount of time? Or does it depend on anything else?

In: 8

Answer 1

Urine and blood tests can only check what is currently in your system. Some drugs can go through your system really fast, like alcohol (most drug tests don’t check for this anyway). Some can stay in your system for a month or more, like marijuana.

Hair tests, which are very uncommon, can detect drug usage from much further back since the traces of drugs basically get stuck in your hair as it grows out.