I just read about a study done in rats regarding ginger extract. It has an unbelievably high LD50 and is safe even when highly dosed. The rats doubled their T values in 28 days at a dosage of 1gr/kg (don't have the time to convert it).
So, I guess we'll all be taking ginger extract soon?
Link to study (disussion is in Dutch, but you can use google translate for those who don't read Dutch):