He says, as a guess, a drug screen would probably show something for most steroids, even 40 days later. That stuff stays in your system a long time. Think about what its purpose is.It's there to produce growth in different organs and stuff in the body, so it's there for a while, he said.e says, as a guess, a drug screen would probably show something for most steroids, even 40 days later. That stuff stays in your system a long time. Think about what its purpose is.