Herb-induced liver injury (HILI) can be caused by supplements containing herbs, natural products, and products used in traditional medicine. Herbal products' most common adverse reaction is hepatotoxicity. Almost every plant part can be used to make herbal products, and these products can come in many different forms, such as teas, powders, oils, creams, capsules, and injectables. HILI incidence and prevalence are hard to estimate and vary from study to study because of insufficient large-scale prospective studies. The diagnosis of HILI is a challenging process that requires not only insight but also a high degree of suspicion by the clinician. HILI presents with unspecific symptoms and is a diagnosis of exclusion. For diagnosis, it is necessary to make a causality assessment; the Council for International Organizations of Medical Sciences assessment is the preferred method worldwide. The most effective treatment is the suspension of the use of the suspected herbal product and close monitoring of liver function. The objective of this review is to highlight the necessary steps for the clinician to follow to reach a correct diagnosis of herb-induced liver injury. Further studies of HILI are needed to better understand its complexity and prevent increased morbidity and mortality.
Keywords: causality assessment; hepatotoxicity; herbal quality; herbs; traditional medicine.