Ashwagandha is an evergreen shrub that grows in Asia and Africa. It is commonly used for stress. Ashwagandha contains chemicals that might help calm the brain, reduce swelling, lower blood pressure, and alter the immune system. Ashwagandha, also known as "winter cherry,"that helps to improve the body's ability to maintain physical effort and helps the body to tackle various types of stress. Perhaps the most famous ayurvedic immune booster herb that is used in many tonics and formulas, ashwagandha is known as a revitalizing herb that maintains proper nourishment of the tissues, particularly muscles and bones, while supporting the proper function of the adrenals and reproductive system. Not surprisingly, Ayurvedic physicians have regarded the use of ashwagandha as one of the best ways to improve the immune system naturally. It remains an important ingredient in some of the most popular Ayurvedic remedies and treatments for disorders that involve weakened immune function.