The most used adaptogen is Ginseng. Chinese Red and White, Korean Red and White, Japanese, American and Siberian. They are divided into yin and yang. Chinese and Korean being the most yang. When my wife takes these 2 she gets sleepy. When I take them I am compelled to fight...anything...except her. She is very yang, more than me and I have to borrow the pants if I want to go out. American, which is the most yin, gives her great energy. It is good for me too. Siberian is not a true ginseng yet has many of the same properties. They have given rats the equivalent of 250lbs of Siberian and they can't kill them. You can drink 44 cups of coffee and that amount of caffeine can kill you, if your bladder doesn't burst first. Point being, try them all to see what works for you. Then, as you age, reasses the type and dosage. Best to pick 2 or more adaptagons so you don't build a tolerance. Schizandra, Withania, Ashwaganda are all effective. If yo are diabetic, ginsengs can lower BS. If you are hypertensive, they can raise or lower BP so pay attention. Go to http://www.consumerlab.com/. They are an independant lab that tests most supplements. When I first investigated Ginseng, consumerlabs broke the story that of the top 10 Gnseng supplements, 8 had no ginseng, and the of other 2. one had 9% and the other 10%. Best, go to a Chinatown, buy Ginseng whole root. Slice it, rest overnight in water and chew a tiny piece. Nothing like gettin back to your roots. Just remember, the Chinese say...if you take Ginseng when you are young, what will you take when you are old? I second the reduce your daily stress first, then supplement...or my wife will kick your ass.