Steroids will only be detected if it is also listed in the lab orders to test for it. You better make sure when you get there because they don't always tell you ahead of time what they are all testing for.
No THC is only found in marijuana... It is a crystal like substance that is the culprit for causing a high... Without THC you won't get high hence not being able to get high off of female plants because they don't have THC
They would have to test for steroids. Steroids do not have THC in them so would not test positive for THC.