Nutraceutical Applications of Withania somnifera: The Scientific Knowledge for Rational Modern Use of the “Ayurvedic Adaptogen”

Withania somnifera L. (Dunal), commonly known as Ashwagandha, is widely used in traditional medical systems, particularly Ayurveda, and is increasingly included in nutraceuticals and dietary supplements. This narrative review summarizes and critically discusses the literature published from 2015 to 2026 on WS, with a focus on CNS-related outcomes, proposed mechanisms, extract standardization, dosage, and safety considerations. Evidence from preclinical research and human studies suggests that WS preparations may influence stress-related and sleep-related outcomes and support neuroprotective pathways suggesting a significant role in nutraceuticals; however, the overall strength of evidence varies across indications and products, and heterogeneity in extract composition and study design limits firm conclusions. Further well-designed, adequately powered clinical trials using standardized preparations are needed to clarify efficacy, mechanisms of action, and long-term safety.