• Home
  • Ashwagandha Scientific Review

A Scientific Review of Ashwagandha


Cultures that practice alternative forms of medicine have long used herbs as a form of medicinal aid. Among the many herbs used by ancient systems of medicine, ashwagandha is especially popular. What makes ashwagandha so special is its adaptogenic content. Herbs that contain adaptogens are believed to help bring balance to bodily systems, including the ability to help the body to deal with stressors that come from every corner of life and leave a lasting effect on our physical and mental state.

What is Ashwagandha


Ashwagandha is an evergreen shrub that is native to India and Africa that belongs to the same nightshade family as tomatoes and peppers. Its name comes from the Sanskrit language and means “smell of a horse,” a term used to describe the odor of its roots as well as its reputation for giving those who ingest it the vigor and strength of a stallion.

In the ancient Indian system of Ayurveda, ashwagandha, also known as Indian ginseng or winter cherry, is regarded as one of the most important herbs for its potential to promote physical and mental vitality and longevity. References to the plant appear in ancient texts dating back centuries and include descriptions of its oval-shaped leaves, reddish-orange fruit, and roots. For more than 3,000 years, Ayurvedic practitioners have used every part of the plant in tonics for a variety of ailments, including fever, constipation, skin infections, rheumatism, infertility, nervous breakdowns, and exhaustion.

Intrigued by the centuries-old use of ashwagandha, modern-day researchers have launched a slew of studies investigating the adaptogenic properties of ashwagandha as well as other potentially beneficial qualities of the plant. Preliminary studies, which have mostly been conducted on animals or in human cell cultures, have found a scientific basis for the therapeutic use of ashwagandha. The herb “appears to exert a positive influence on the endocrine, cardiopulmonary, and central nervous systems,” according to a review of studies published in the Alternative Medicine Review. Researchers also noted that the chemical compounds of ashwagandha exhibited “little or no associated toxicity.”

While scientists have identified bioactive chemicals in ashwagandha such as withanolides (steroidal lactones), alkaloids, and saponins, they still don’t understand exactly how the herb reacts in the body or its impact over an extended period of time. They do know that ashwagandha contains free radical scavenging antioxidants that support immune health and may help regulate inflammatory responses in the body. But more extensive studies and clinical trials are needed to support current claims about its effects and to establish best practices for using it.

The most promising studies on ashwagandha have focused on its capabilities for supporting the body’s adaptive response to the effects of stress from internal and external toxins. Lab studies have found that ashwagandha may have a calming effect on the body by lowering the levels of the stress hormone cortisol produced by the adrenal glands, and help to regulate the excitatory neurotransmitter glutamate, which stimulates brain cells and nerves. The herb has also been shown to mimic the inhibitory neurotransmitter GABA (gamma-aminobutyric acid), which slows down activity between neurons to relax the brain.

Several small clinical trials have found that ashwagandha, when combined with other healthy habits such as a balanced diet and deep breathing, may help lessen the impact of stress and possibly ease the severity of symptoms of anxiety and depression such as fatigue, sleeplessness, and moodiness. One of the most recent studies, published in the Indian Journal of Psychological Medicine, found that people with a history of chronic stress who took 300 milligrams of an ashwagandha root extract twice daily exhibited lower cortisol levels and better resistance toward stress than the placebo group.

Other Potential Benefits


Along with its potential for providing stress and anxiety relief, researchers have found that ashwagandha may help with the following:

Joint pain

Ashwagandha has traditionally been used to ease tenderness and swelling in the joints and is believed to help intercept pain signals from the nervous system to the brain. Limited evidence from animal studies suggests that it may be protective against experimentally induced rheumatism. In one 2015 pilot study published in the Indian Journal of Medical Research, patients with joint pain who took ashwagandha powder twice daily for three weeks, followed by an Ayurvedic mineral-based preparation with honey for four weeks, showed improvement in joint swelling, pain and tenderness after seven weeks.

Hormone function

Ashwagandha has been shown to support the function of endocrine organs, such as the adrenal glands and the thyroid gland, and help with regulating the hormones they produce. Lab studies have found that the herb may help balance cortisol levels when stress is high and stimulate hormone production in the thyroid. Researchers have even explored the effect of ashwagandha on testosterone production, particularly in relationship to stress-induced infertility. In a 2010 study by Indian researchers of 75 infertile men, the group that received ashwagandha showed less oxidative stress and increased sperm count and motility, along with higher testosterone levels. Another study found that men who took ashwagandha for stress exhibited higher antioxidant levels and better sperm quality. After taking three grams of the herb a day for three months, 14 percent of these men had gotten their partners pregnant.

Heart health

Several lab and human studies have found that ashwagandha may have a positive effect on blood sugar, cholesterol and triglyceride levels. In a small study, people with type 2 diabetes who supplemented their diets with ashwagandha root powder for 30 days showed a “decrease in blood glucose comparable to that of an oral hypoglycemic drug,” the study noted. A 2010 clinical trial published in the International Journal of Ayurveda Research found that ashwagandha may be useful for supporting cardiovascular muscle strength and endurance, particularly when used in combination with another Ayurvedic herb known as Arjuna. In a recent test-tube study published in the journal Phytochemistry, researchers observed that using a leaf extract of ashwagandha in muscle cells resulted in increased insulin secretion and sensitivity.

Brain function

Ayurvedic practitioners have long believed that ashwagandha was capable of enhancing memory, reaction times and the ability to perform tasks. Not only does it contain antioxidants that scavenge for free radicals causing oxidative stress in nerve cells, but lab and animal studies have found that ashwagandha may help slow damage to connective pathways in the brain that can ultimately result in the loss of memory and function. In a controlled study published in the journal Pharmacognosy Research, a small group of healthy men who took 250 milligrams of the herb twice daily for 14 days reported greater improvement in reaction time and task performance than those who received a placebo. A longer eight-week study published in the Journal of Dietary Supplements also found that 50 adults taking 300 milligrams of the ashwagandha root extract twice daily experienced greater gains in memory, task performance and attention than those given a placebo.

Dosages and Caveats for Ashwagandha


In centuries past, ashwagandha was usually ground into a powder and mixed with water, milk, honey or ghee (clarified butter). But today it’s available in a variety of forms, including the dried root, capsules, tablets, liquid extracts, and tea bags. A small amount of the herb goes a long way. While there is no established dosage, experts generally suggest 1 - 2 teaspoons of the powder or 3 - 6 grams of the dried root per day for optimal results.

Supplements containing the ashwagandha root typically start at dosages of 300 - 500 milligrams taken once or twice a day and are standardized to at least 1.5 percent of withanolides (the primary active ingredient in ashwagandha) per dose. Proper dosage may vary based on factors such as age and health history, so it’s best to consult with a doctor before taking ashwagandha regularly. Never use it as a replacement for recommended medication.

Ashwagandha has a slightly bitter taste, so it’s best when consumed with recipes and meals or blended with tea, a smoothie, or almond milk and honey. While it typically has few side effects, ingesting the herb in large quantities can result in an upset stomach, diarrhea, or vomiting. Certain prescription drugs, allergy sensitivities, and medical procedures or therapies may also adversely affect on how ashwagandha interacts with the body. Avoid ashwagandha if you are pregnant, suffer from severe gastric irritation or ulcers, have a sensitivity to nightshade plants, or take drugs such as sedatives or immunosuppressants.

Adaptogens like ashwagandha act slowly and won’t work wonders overnight. You may have to take the herb for several weeks before seeing any kind of result, but it could be a great way to supplement your health regimen, especially when stress has got the best of you.