To me, one reason I fast is to give my body a rest. That includes not taking supplements of any kind. Even when juice fasting, I only take in fruit and vegetable juices. I don't take vitamins or anything. To each his own, but I believe fasting should also be a modification of a person's typical behaviors. For me, fasting is a chance to correct bad habits and bad nutrition. All this said, I have heard of Hoodia, but don't know what it is exactly. I am personally trying to rid my body of toxins and am not enthusiastic about putting any none fruit or vegetable substance in my body. I have done 36 hour weekly fasts before. It was a time to develop self-control naturally through good old will power.
I laugh as I read this, because since I don't know anything about Hoodia, I cannot disapprove or approve of it. I don't even know if this all was worth saying, lol. Whatever happens, I hope your personal fasting goals are achieved in a healthy way. Take care.