I just found a website that claims that long term usage might lead to toxicity. Is this true? I guess it depends on the dosage. One website recommended 4 days on and two off, while others seem to imply that usage for at least a month in a row is no problem. Other websites imply that it can be taken indefinitely. I guess it depends on the dosage. Since extracts vary so much in concentration, it is hard to gauge this.