What Are Side Effects Of Taking OEP?

Ok Im in the army and someone recently had a heart attack, the army medics couldnt single out OEP to be the reason for it, I know that there are certain supplements you arent supposed to take with this and alot of people dont follow the directions. They always over do it to find results faster which never works. My question is what are some of the worse side affects anyone has seen from this supplement?