Supplements to stay away from..

Hey I was just wondering if anyone could give me some insight on some supplements that may be harmful.. if there is any. I love taking supplements but I am not sure if they are bad for you because they really haven't been around too long to see how older people are responding to them. I am a little conscious about pre-workouts in general. All that caffine with mysterious ingredients seem like a death sentance for the heart. I was reading an article on how jack3d just got banned from military bases for causing kidney failure/ heart attacks. Like I said, I am not going to pretend I know what is harmful and what is not, I just wanted to see if anyone had any insight on any particular products that may be harmful so I can stay away from them. Thanks.

Vanadyl sulfate is the only thing that immediately comes to mind.

And 1,3 is safe in moderation, the military controversy is due to a toxicology report that showed 1,3 in the system of the soldier, but it was not the cause of death.