Understanding adaptogens: The action that evades us

Adaptogens are among the most common class of herbal medicines prescribed by herbalists today, and the term is rapidly disseminating into the wider community. Yet, despite the ubiquitous use of adaptogens in clinical practice, there is very little research available which clearly defines the mechanism of action. Although definitions have been proposed, no single definition has been agreed upon by researchers. It appears that the polyvalent action of adaptogens cannot be measured from a conventional pharmacological paradigm of single receptor-based perception of drug action, when adaptogens likely have a multi-targeted action on multiple receptor sites. The multi-target action has been a limiting factor in the progression of clinical trials as the most appropriate method to measure adaptogens remains unknown. Adaptogen is a key concept in Western herbal medicine, with roots spanning more than a century. Bridging the gap between clinical use of this concept and clinical data is long overdue. For this to happen, steps need to be taken to initiate the process of standardisation of the term, as is being seen with other traditional medicine concepts being formalised by the World Health Organization (WHO). This begins with consensus on the definition and a thorough examination of the mechanism of action from a broader pharmacological perspective.