Have you ever used cannabis and been concerned about a drug test such as a pre-employment screening? You may have questions like “How long does weed stay in your system?” The main cannabinoid present in marijuana is tetrahydrocannabinol, or THC for short. This is the chemical in marijuana that makes people feel “high,” and it can stay in the body for several days or even weeks. 
The time this chemical stays in the body or continues to show in a drug test depends on many factors. A person’s body fat ratio, frequency of use, amount of THC consumed, and even the sensitivity of a drug test can all play a role in determining whether or not the presence of cannabinoids will show up. 
Drugs such as alcohol may completely disappear from the body in just a few hours.  Unfortunately, by comparison, weed lingers much longer. This is because THC binds with the fat cells in our bodies and does not entirely disappear until those fat cells are consumed for energy.  Needless to say, the lower the fat percentage on your body and the faster the rate at which you burn and process fat (think exercise + metabolism), the more quickly the substance will not show up. 
What if you just had one puff, though? How long does one hit of weed stay in your system?
Drug tests can detect tetrahydrocannabinol, or THC, in urine, blood, and hair for many days after use, while saliva tests can typically only detect THC for a few hours.  So chances are if you just smoked marijuana once, an oral test would only pick it up for a few hours or days. This is because of the way the body metabolizes THC.
What about THC-infused edibles? How long do they stay in your system?
Well, how long edibles stay in your system for drug tests will again vary based on the factors previously discussed above.
If you eat a marijuana edible that contains THC, that cannabinoid will bond with your fat cells and can take a week up to even a month before it is processed. In rare cases where someone is a chronic user, it can even take multiple months before their system is completely flushed clean of all cannabinoids. 
One hit of weed won’t stay in your system very long, however, so if you’re concerned about being drug tested and intent on smoking, you are better off going light than you are consuming THC edibles. The type of edible does not matter so much, however, so if you were wondering how long a THC gummy stays in your system compared to, say, a brownie, for instance, the difference is negligible. 
If you’re worried about passing a drug test, your best bet is to avoid consuming THC, but again if you are intent on it, try to make sure you give yourself at least a week before being tested at an absolute minimum. A month is a safe bet for most people to ensure you are clean. Always discuss any medications you may be taking with your doctor before consuming a cannabis product.