Can kissing someone who has been taking drugs show up on drug tests?
Hi there, good question!
In theory, if you kiss someone who has taken drugs and then have a drug test, it's possible that the drug will get into your system and the drug test may come back positive. For example, if cocaine powder is snorted, it will start to drip down the throat, so it's theoretically possible that kissing someone who has just used cocaine could show up in a saliva drug test.
However, in reality, the amount of a drug in your mouth from kissing someone who has used it would be too small to be detected in a saliva drug test. This is because the saliva tests aren't sensitive enough to pick up on small amounts (they have a minimum cut-off level), and because the concentration of the drug will be less in your mouth (having mixed with your "clean" saliva) than in the other person's.
So in theory this could happen for drugs that are eaten/smoked/snorted, but it reality it won't.
Hope that answers your question. Have a look at the link below for more on drug testing. Take care.