An adaptogen is a herb or mushroom that helps the body adapt to physical and mental stress without overstimulating it. The term was first formalised by Soviet pharmacologist Nikolai Lazarev in the 1940s and has been studied since. Research on well-known adaptogens like ashwagandha, rhodiola rosea, and ginseng shows credible evidence for reducing markers of stress fatigue and improving physical endurance. The evidence is stronger for some (ginseng, rhodiola) than others. They work slowly and cumulatively — most studies show meaningful effects after 4–8 weeks of consistent use — so they’re not a quick fix. The best evidence exists for fatigue related to chronic stress, rather than fatigue caused by medical conditions.
