I started when I was 16. At the time I was an amatuer boxer and my trainer used to make me take it a month or so before a fight, along with diuretics before my weigh ins. Needless to say, I got an athletic scholarship to a college for my efforts, but I did'nt need it at the time to get where I got. I regret very much for following the advice of my "mentor." I'm only 5'10'' and 206lbs now, and who knows how big and tall I could have been.
In answer to your question, yes, I regret using steroids at a young age very much.