"'Adaptogen was coined in France in 1947 to describe plant compounds that promote hormesis or 'normal' functioning of the human organism. They are increasingly popular for modulation of stress, anxiety, fatigue, and as a generalized 'tonic.' While there is copious research on their effects and lack of toxicity in Russia and China, much less is published in the English literature. However, as just one example, in an American rat study, the average dose of Rhodiola, one of my favorite adaptogens, to achieve 50 percent toxicity was over 3,000 mg/kg. In other words, a 150-pound person would have to ingest about 95 pounds a day of Rhodiola. Since I use between 100 and 500 mg for my patients, that's not likely to happen.
The only adaptogen to be approached with caution is licorice. Licorice contains glycyrrhizin, which can dramatically increase blood pressure by affecting kidney function. This can be avoided by always buying de-glycyrrhizinized licorice (commonly sold as DGL).
One other caveat for which there is no good consensus: Should these agents be taken chronically for good health or sporadically when needed for a boost? Over the years, I have sided with more chronic daily use for myself and my patients and include some of my recommendations in my book, The Plant Paradox. —Dr. Steven Gundry, author of The Plant Paradox