I have used Syntrax Guggulbolic ( 6 a day) without any issues. Out if the other guggulsterones out there, it was the only one that I noticed a difference.
As of late, I stick with Liquid L-Carnitine, ON's Thermocuts and Cuban Coffee (no sugar).
I think the legal issue with Syntrax was that they had a product that contained tiratricol (tricana) (t3). It resulted in hypothyroid problems with users.