FBI does not accept anyone who has past drug usage of a substance outside of minimal marijuana less than ten years ago.   It's all on their website.   Even with their new "relaxed" standards (and they are the most relaxed of all FED LE agencies on this issue) they pretty much do not accept anything outside very minimal marijuana experimentation.  Best thing to do is go to the DEA website, under the drug classification tables, and see the severity or grade level your past drugs are in.   Then figure out your eligibility.  Remember, you will take a poly.  It's accuracy may be debatable, but you must factor that in nonetheless.

I applied for a couple of FBI positions and now think I should rescind my applications based on what I have heard.  I consumed mushrooms 7-8 years ago once.  I don't remember the exact date.  It was a terrible experience and it was given to me by someone (they did tell me what it was but I didn't go out and buy it).  It was the only time I ever did a drug other than pot, and I learned my lesson.  Am I correct in assuming this disqualifies me from FBI employment (specifically, secret agent and investigative specialist positions)?  I had thought it was longer ago when I had done it when I applied but I have been rethinking it and getting increasingly nervous about disqualification.