## 1 Introduction  
The World Health Organization (WHO) stated that approximately 30% of drugs contain plant-derived compounds, and approximately more than half of the global population depends upon plant-derived medicines, including those of Ayurveda, the traditional plant-based medicine of India [1, 2]. The Botanical Survey of India (BSI) reported that approximately 7500 of the 15,000 plant species in India are used for medicinal purposes [3]. A list of 32 therapeutically important plants of India prioritized by the National Bank for Agriculture and Rural Development (NABARD) includes _Withania somifera_, regularly called as ashwagandha. The National Medicinal Plant Board (NMPB), India, has also described _Withania_ species as a valuable therapeutic plant in great demand in domiciliary and global markets [4, 5].  
_W. somifera_, indigenous to the Indian sub-continent, is used as indigenous medicine throughout Southeast Asia. Its roots, seeds, and leaves have been used for over 3000 years for multiple health purposes, and are included in Ayurvedic, Allopathic, Unani, homeopathic, and other medical systems [6]. Due to its superlative therapeutic properties, it is also known as the Queen of Ayurveda or a Rasayana herb. _Withania_ spp. are members of the Solanaceae family ([PERSON], 1862-1883), also known as the deadly nightshade family. The Solanaceae family embraces 84 genera, comprising 3000 species, distributed all over the globe [6]. The genus _Withania_ contains 26 species, only 2 of which,W. sommifera_ and _W. coagulans_ (known as Paneer booti, Ashutosh booti or rishyagandha), are economically and medicinally important in many regions [7]. Other potentially important species are _W. simouii_, _W. adunensis_, and _W. riebeckii_.  
Two subspecies have also been reported--_W. sommifera Dunal_ and _W. sommifera Kaul_[8]. Both species of _Withania_, i.e., _W. sommifera_ and _W. coagulans_, are cultivated on a large scale in India [9]. In Sri Lanka, two cultivars of _W. sommifera_ are used, but the Indian cultivar is more suitable for drug development due to its starchy nature, whereas the local cultivar has fibrous roots that are difficult to transform into powder [10]. Its common name, ashwagandha, is a combination of two Sanskrit words, ashwa and gandha, and means \"horse's smell\", referring to the sweaty horse-like smell of the roots [9,11]. Other names include winter cherry, poison gooseberry [12,13], or \"Indian ginseng\", due to its restorative properties.  
However, the mechanism of drug use by _W. sommifera_ has not been elucidated. Accordingly, there are unreasonable points in the current _W. sommifera_ quality management system. In fact, its medicinal value has received less attention, despite its long history of clinical application. In this review, information regarding various aspects of _W. sommifera_ was collected from peer-reviewed journals for the period 2000-2022. PubMed, Shod Ganga, Web of Science, Google Scholar, etc., was used to retrieve electronic information. Based on this information, we performed a full review of _W. sommifera_ aiming to provide information to better understand the pharmacological mechanism and potential medicinal applications of this species, and to develop a reasonable quality control system for _W. sommifera_ as medicinal material in the future.