Ashwagandha (Withania somnifera) root is a herb of the ages. the traditional medicine of India and is considered an 'adaptogen', a term used to describe herbs that improve physical energy and athletic ability, increase immunity to colds and infections and increase fertility. One reason for the reputation of ashwagandha as a general energy-promoting, disease-preventing tonic may be its effect on the immune system. A number of studies have shown significant increases in white blood cell counts and other measures of strengthened immunity in rodents given ashwagandha or certain chemicals extracted from the herb. Ashwagandha may also have a mild sedative effect on the central nervous system and in animal studies it has been shown to be a muscle relaxant. It is commonly used to increase vitality, particularly when recovering from chronic illnesses and pain management for arthritic conditions. Ashwagandha may also help regulate blood sugar which aids in suppressing sugar cravings. Ashwagandha seems to show positive effects on the endocrine, cardiac, and central nervous systems. It is one herb that could help your body produce its own thyroid hormones.