The 500 mg a day is from the book "Staying Young" by Drs Michael Roizen & Mehmet Oz (not that that necessarily makes it correct). They recommend it for lowering LDL & Triglycerides. As far as side effects, they say its rarely associated with liver problems. I'm having a retest in October so I'll see if it or something I'm doing is having a beneficial effect.
As far as the energy issues, I regularly ride for 2 or more hours & have not noticed any effect on energy, performance or endurance.
BTW: I'm not the OP.
Dan