Pretty much once at MEPS, and you can admit to a certain amount of using certain drugs without any punishment, even.
I can't even tell you how many people I've known to spend weeks flushing drugs out of their system before they knew they were going to MEPS. They certainly didn't go out of their way to stop using drugs, just to pass.
The whole military entry process is one big test of how well you can lie to get in, in the eyes of most of the young people trying to get in. Who is going to admit to smoking a joint last month when it might get them DQd?
