Ashwagandha is a medicinal herb that is gaining mainstream attention for its ability to reduce stress and anxiety, improve sleep, and maybe even level up your athletic performance. But what else does it do, how much should you take, and are there any side effects? In this ultimate guide to ashwagandha, we’re sharing everything you want to know about this herb, and why science says you should add it to your supplement routine.
What is ashwagandha?
Ashwagandha (Withania somnifera), also known as “Indian ginseng” or “Indian winter cherry,” is an evergreen shrub native to India and Southeast Asia and a commonly used medicinal herb in Ayurvedic medicine. Extracts from the ashwagandha root or leaves (typically in the form of a powder) are used to treat various conditions and can provide numerous health benefits.
What does ashwagandha do?
Ashwagandha is commonly used to alleviate stress, anxiety, depression, and insomnia. It may also be beneficial for reducing blood sugar, cholesterol, and inflammation, as well as enhancing sleep, immunity, sports performance, memory, and brain function in both men and women. Additionally, ashwagandha may help improve male fertility and improve sexual dysfunction in females.
Sources of ashwagandha
The ashwagandha plant is the most natural form of this medicinal herb. In some parts of the world, people eat the shoots, seeds, and fruit [20
]. The plant’s leaves and roots can also be used to make tea or ground into a powder that can be added to foods and beverages.
Ashwagandha is also available as a dietary supplement which typically contains a standardized and more concentrated ashwagandha extract that is roughly ten times more potent than the whole herb [21
]. These supplements are available in varying strengths in capsule, powder, and liquid form.
How much ashwagandha should you take?
How much ashwagandha you should take depends on the benefits you’re looking to achieve and how your body metabolizes it. Evidence suggests that 250-600 mg/day can improve sleep quality, whereas 600–1,000 mg/day may be more beneficial for athletes seeking performance benefits [1
Typical ashwagandha root extract dosages range from 250–600 mg/day, with the most common dosing protocol being 600 mg/day divided into two doses for morning and night [1
]. However, one study found dosages ranging from 750 to 1250 mg/day for 30 days to be well-tolerated and safe, and while more research is needed, it appears safe to take up to 1,000 mg/day for up to 12 weeks [10
What are the side effects of ashwagandha?
When taken in large doses, the most common side effects of ashwagandha include upper and lower digestive upset, such as nausea, gas, bloating, diarrhea, and vomiting [19
]. Though rare, liver problems are also possible [19
When to take ashwagandha
Ashwagandha can be taken at any time of day, with or without food, but you may want to split your doses up to take in the morning and night. Additionally, studies have found that taking ashwagandha before bed may improve sleep quality by helping you fall asleep and achieve REM sleep faster [5
How long does ashwagandha take to work?
Ashwagandha can take anywhere from 2-3 days to several weeks to work. Current research suggests it may take ten or more weeks to achieve maximum benefits related to stress and anxiety reduction [5
How long does ashwagandha stay in your system?
How long ashwagandha remains in your body will vary from person to person and depend on factors like your age, weight, dose, metabolism, health conditions, and other medications taken. However, anecdotal evidence suggests ashwagandha’s effects can last a couple of days or up to two weeks after stopping this supplement [1
Here’s what science has to say about ashwagandha’s role in stress reduction, blood sugar control, inflammation, and cholesterol levels.
Reduced stress, anxiety, and depression.
Studies show taking ashwagandha can reduce anxiety associated with chronic stress and anxiety disorders and may be more effective for reducing social anxiety than some medications [1
]. In addition, ashwagandha supplementation may also improve a sense of well-being and reduce social dysfunction in anxiety patients.
Ashwagandha also appears to significantly lower the symptoms of stress and its associated disorders–like fatigue, insomnia, and cognitive impairment–and reduce cortisol levels in the blood. Human studies have associated ashwagandha supplementation with cortisol reductions ranging from 14.5 to 27.9% in stressed but otherwise healthy individuals, which is substantially greater than many other supplements [1
]. Moreover, research suggests ashwagandha may have some anti-depressive effects, although they are less notable than the reductions in anxiety [1
Improved quality of sleep.
Several small studies suggest ashwagandha can improve sleep, particularly in those who have stress-related insomnia [2
A systematic review of five randomized controlled trials observed a small but significant improvement of overall sleep, with the most notable differences observed in those diagnosed with insomnia and who took ≥600 mg/day for eight or more weeks [2
]. Another recent study of 60 people found that those who took 300 mg of ashwagandha twice daily for ten weeks experienced better sleep quality than those who took a placebo [5
]. Researchers believe these effects stem from triethylene glycol (a compound known to induce sleep) and withanolides (substances that appear to improve the body’s ability to cope with stress) [3
Improved blood sugar.
Preliminary research suggests ashwagandha may help lower blood sugar levels in healthy individuals and people with diabetes.
A systematic review of 24 studies, including five clinical studies with diabetics, found ashwagandha supplementation significantly reduced blood sugar, HbA1c, insulin, blood lipids, and oxidative stress markers with no adverse outcomes [7
]. Dosages varied greatly between these studies; however, as little as 250 to 500 mg/day may significantly benefit blood glucose and HbA1c.
Despite these positive early findings, more research is necessary to prove ashwagandha’s effectiveness in the treatment of diabetes.
Reduced risk of infection and inflammation.
Early research suggests supplementing with ashwagandha may also have beneficial effects on immunity and inflammation. A preliminary in-vivo study found 12 mL of ashwagandha root extract/day increased levels of T-cell activation and natural killer cell activity, two essential immune cells that help fight infection [8
]. Additionally, research suggests oral supplementation of ashwagandha can effectively reduce C-reactive Protein (CRP) levels, a protein produced by the liver that increases with inflammation. In one study, 250 mg/day resulted in a 36% decrease in CRP compared to a placebo group [9
Though research has produced promising results in reducing inflammation and improving immune activity, more robust human studies are needed to prove ashwagandha’s benefits.
Lowered cholesterol levels.
One study in healthy individuals found higher doses of ashwagandha (beginning at 750 mg for ten days, followed by 1000 mg and 1,250 mg for ten days each) decreased total cholesterol in participants by nearly 10%, including those with normal cholesterol levels [10
]. In another study, participants with high cholesterol who took 250 to 500 mg/day of ashwagandha experienced slight yet scientifically significant decreases in LDL cholesterol compared to those taking a placebo [9
Additionally, other research found that those with metabolic syndrome experienced a 12% decrease in triglycerides after supplementing with 1200 mg/day of ashwagandha for 30 days [11
]. However, this effect was not observed in individuals with normal triglycerides.
Ashwagandha may also increase HDL (good) cholesterol, but more research is needed in this area [1
Improved athletic performance.
Emerging evidence suggests that ashwagandha may prove beneficial for athletic performance, including increased endurance, speed, and strength.
One study in elite cyclists found 500 mg twice daily of ashwagandha significantly increased time to exhaustion on a treadmill test compared to a placebo group [12
]. Similar performance improvements and increases in VO2 max have also been noted in both athletes and untrained individuals [1
In addition to enhancing endurance, ashwagandha may also benefit sprinting and strength training performance. One study in males found taking 500 mg of ashwagandha daily improved intermittent sprint performance (including power output and sprint velocity) in normal, healthy individuals [13
]. Moreover, another study shows that men who took 600 mg of ashwagandha daily for eight weeks increased muscle strength by 1.5-1.7x and muscle size by 1.6-2.3x compared to those taking a placebo [14
Based on the current research, doses of 500 to 1,000 mg/day of ashwagandha may provide small increases in endurance, sprint capacity, and strength in as little as eight weeks. While most studies have focused on men, more research is needed to determine whether ashwagandha supplementation can enhance athletic performance in women.
Improved memory and brain function.
Ashwagandha has been shown in many studies to enhance numerous aspects of cognitive function, including reaction time, task performance, memory, and attention.
In one double-blind, placebo-controlled human study, healthy men who took 500 mg of ashwagandha extract daily reported significant improvements in their reaction time and task performance compared to those who received a placebo [16
]. Multiple studies have also shown ashwagandha can improve memory and attention in individuals with anxiety, bipolar disorder, and cognitive impairment [1
]. However, more research is needed to determine if ashwagandha can enhance the memory of healthy individuals.
Ashwagandha benefits for women
Studies show that ashwagandha has numerous benefits for women, including increased arousal and improved sexual satisfaction [17
]. Another small clinical study suggests ashwagandha supplementation may alleviate mild to moderate symptoms of perimenopause, the time during which your body makes the natural transition to menopause [18
Ashwagandha benefits for men
Ashwagandha has numerous benefits for men, as scientific evidence suggests ashwagandha may improve male fertility by naturally increasing testosterone levels and enhancing sperm quality in infertile men [1
]. One randomized trial showed patients with a low sperm count that took 675 mg/day for 30 days improved sperm count by 167%, semen volume by 53%, and sperm motility by 57% from baseline, and that those in the placebo group experienced only minimal improvement [15
Research in men also shows ashwagandha can enhance athletic performance in both male athletes and healthy, untrained men [1
Who should not take ashwagandha?
While ashwagandha has many benefits, there are some people who may not be able to use it. Here’s what science has to say about who should not take ashwagandha.
Some evidence suggests ashwagandha might cause miscarriages and should not be taken during pregnancy [19
Breastfeeding: At this time, there is not enough research to determine whether ashwagandha is safe to use when breastfeeding.
Ashwagandha can increase levels of thyroid hormones and should be taken with caution or avoided altogether if you have an overactive thyroid (hyperthyroidism) or if you take thyroid hormone medications [19
]. Moreover, individuals with an overactive thyroid should not take ashwagandha as it can exacerbate hyperthyroidism.
Ashwagandha can increase immune response, so it’s recommended that individuals with autoimmune diseases (such as multiple sclerosis, lupus, rheumatoid arthritis, type 1 diabetes, or other conditions) should avoid taking ashwagandha [19
Immunosuppressants: Since it can increase the activity of the immune system, taking ashwagandha and immunosuppressants simultaneously may reduce the effects of the medication.
Ashwagandha can increase sleepiness and slow breathing, so taking it alongside sedative medications (like Benzodiazepines or CNS depressants) may cause breathing problems and excessive sleepiness [19
Diabetes drugs: Ashwagandha can lower blood sugar levels, so taking both ashwagandha and diabetes medications may cause blood sugar to drop dangerously low.
Blood pressure reducers: Ashwagandha can also lower blood pressure, so taking both ashwagandha and antihypertensive medications may cause blood pressure to drop too low.
Before starting an ashwagandha supplement, you should talk with your healthcare provider to make sure it’s right for you.
Ashwagandha is an evergreen shrub and medicinal herb commonly used in Ayurvedic medicine to alleviate stress, anxiety, depression, and insomnia. Evidence suggests it may also be beneficial for reducing blood sugar, cholesterol, and inflammation while enhancing immunity, sports performance, male fertility, memory, brain function, and more.
While there are many benefits to adding this herb in your supplement routine, it’s recommended that those who are pregnant, breastfeeding, have thyroid conditions, and/or autoimmune diseases should not take ashwagandha. Moreover, people who take certain medications (including immunosuppressants, sedatives, thyroid hormone, diabetes drugs, blood pressure reducers) should also avoid ashwagandha or speak to their doctor before starting this supplement.
Disclaimer: The text, images, videos, and other media on this page are provided for informational purposes only and are not intended to treat, diagnose or replace personalized medical care.