Specific tests include urine, saliva, hair and blood tests ... This article originally appeared on USA TODAY: How long does weed stay in your system? What smokers should know this 4/20.

And if you choose to celebrate, please do so safely ... affect how long THC stays in the system? As noted, the frequency and amount affect how long THC and its metabolites stay in the system.

This sensation only lasts a short while — often a few minutes — but the drug itself can stay ... negative urine test, though the exact amount of time this takes can vary. Can you do anything ...

Drugs like marijuana, cocaine, and MDMA can remain in your system for days, weeks, and even months. But they vary drastically in how long they can be detected in your urine, blood, and hair.