Ashwagandha is perhaps best known for its ability to reduce stress. It’s classified as an adaptogen, a substance that helps the body cope with stress.

Ashwagandha appears to help control mediators of stress, including heat shock proteins (Hsp70), cortisol, and stress-activated c-Jun N-terminal protein kinase (JNK-1) (4Trusted Source).

It also reduces the activity of the hypothalamic-pituitary-adrenal (HPA) axis, a system in your body that regulates the stress response (4Trusted Source, 5Trusted Source).

Several studies have shown that ashwagandha supplements may help relieve stress and anxiety.

In a small study with 58 participants, those who took 250 or 600 mg of ashwagandha extract for 8 weeks had significantly reduced perceived stress and levels of the stress hormone cortisol compared with those who took a placebo.

What’s more, the participants who took the ashwagandha supplements experienced significant improvements in sleep quality compared with the placebo group (4Trusted Source).

Another study in 60 people found that those who took 240 mg of ashwagandha extract per day for 60 days had significant reductions in anxiety compared with those who received a placebo treatment (5Trusted Source).

Thus, early research suggests ashwagandha may be a helpful supplement for stress and anxiety.

However, a recent review of studies concluded that there’s not enough evidence to form a consensus on the most appropriate dosage and form of ashwagandha for treating stress-related neuropsychiatric disorders such as anxiety (6Trusted Source).

SUMMARY

Ashwagandha may be effective for reducing stress and anxiety symptoms. However, more research is needed to form a consensus on appropriate forms and dosing to address stress and stress-related disorders.

Research has shown that ashwagandha may have beneficial effects on athletic performance and may be a worthwhile supplement for athletes.

One analysis of research included 12 studies in men and women who took ashwagandha doses between 120 mg and 1,250 mg per day. The results suggest the herb may enhance physical performance, including strength and oxygen use during exercise (7Trusted Source).

An analysis of five studies found that taking ashwagandha significantly enhanced maximum oxygen consumption (VO₂ max) in healthy adults and athletes (8Trusted Source).

VO₂ max is the maximum amount of oxygen a person can use during intense activity. It’s a measurement of heart and lung fitness.

Having optimal VO₂ max is important for athletes and nonathletes alike. Low VO₂ max is associated with increased mortality risk, while higher VO₂ max is associated with a lower risk of heart disease (8Trusted Source).

Additionally, ashwagandha may help increase muscle strength.

In one study, male participants who took 600 mg of ashwagandha per day and participated in resistance training for 8 weeks had significantly greater gains in muscle strength and size compared with a placebo group (9Trusted Source).

SUMMARY

Ashwagandha may help improve measures of physical performance in athletes and healthy adults, including VO₂ max and strength.

Some evidence suggests that ashwagandha may help reduce symptoms of other mental health conditions, including depression, in certain populations.

In one study, researchers looked at the effects of ashwagandha in 66 people with schizophrenia who were experiencing depression and anxiety.

They found that participants who took 1,000 mg of ashwagandha extract daily for 12 weeks had greater reductions in depression and anxiety than those who took a placebo (10Trusted Source).

What’s more, findings from another study suggest that taking ashwagandha may help improve total symptoms and perceived stress in people with schizophrenia (11Trusted Source).

Limited research from 2013 also suggests that ashwagandha may help improve cognitive impairment in people with bipolar disorder. However, more research is needed (12Trusted Source).

Additionally, a study from 2012 found that stressed adults who took 600 mg of ashwagandha extract per day for 60 days reported a 77% reduction in symptoms of depression, while the placebo group reported a 5% reduction (13Trusted Source).

However, only one of the participants in this study had a history of depression, so the relevance of the results is unclear.

Although some findings suggest that ashwagandha may have some antidepressant effects in certain people, you should not try to use it as a substitute for antidepressant medication.

If you’re experiencing symptoms of depression, talk with a healthcare professional so you can get any help or treatment you may need.

SUMMARY

The limited research available suggests that ashwagandha may help reduce symptoms of depression and benefit people with some mental health conditions. However, more research is needed.

Ashwagandha supplements have been shown in some studies to benefit male fertility and increase testosterone levels.

In one study, 43 overweight men ages 40–70 who had mild fatigue took tablets containing ashwagandha extract or a placebo daily for 8 weeks.

The ashwagandha treatment was associated with an 18% greater increase in DHEA-S, a sex hormone involved in testosterone production. Participants who took the herb also had a 14.7% greater increase in testosterone than those who took the placebo (14Trusted Source).

Additionally, a review of four studies found that ashwagandha treatment significantly increased sperm concentration, semen volume, and sperm motility in men with low sperm count.

It also increased sperm concentration and motility in men with normal sperm count (15Trusted Source).

However, the researchers concluded that there’s currently not enough data to confirm the potential benefits of ashwagandha for male fertility and that more high quality studies are needed (15Trusted Source).

SUMMARY

Ashwagandha may help increase testosterone levels and may have some potential benefits for male fertility. However, more research is needed.

Limited evidence suggests that ashwagandha may have some benefits for people with diabetes or high blood sugar levels.

A review of 24 studies, including 5 clinical studies in people with diabetes, found that treatment with ashwagandha significantly reduced blood sugar, hemoglobin A1c (HbA1c), insulin, blood lipids, and oxidative stress markers (16Trusted Source).

It’s believed that certain compounds within ashwagandha, including one called withaferin A (WA), have powerful antidiabetic activity and may help stimulate your cells to take in glucose from your bloodstream (17Trusted Source).

However, research is limited at this time, and more well-designed studies are needed.

SUMMARY

Limited evidence suggests that ashwagandha may reduce blood sugar levels through its effects on insulin secretion and cells’ ability to absorb glucose from the bloodstream.

Ashwagandha contains compounds, including WA, that may help reduce inflammation in the body (18Trusted Source).

Researchers have found that WA targets inflammatory pathways in the body, including signal molecules called nuclear factor kappa B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2).

Animal studies have shown that WA may also help reduce levels of inflammatory proteins such as interleukin-10 (IL-10) (18Trusted Source).

There’s some evidence that ashwagandha may help reduce inflammatory markers in humans too.

In one study from 2008, adults experiencing stress took ashwagandha extract for 60 days. As a result, they had significant reductions in C-reactive protein — an inflammatory marker — compared with those who consumed a placebo (19).

In another study, researchers gave people with COVID-19 an Ayurvedic drug containing 0.5 grams of ashwagandha and other herbs twice per day for 7 days. This reduced participants’ levels of inflammatory markers CRP, IL-6, and TNF-α compared with a placebo (20Trusted Source).

The treatment formulation also contained:

• 1 gram of giloy ghanvati (Tinospora cordifolia)
• 2 grams of swasari ras (a traditional herbo-mineral formulation)
• 0.5 grams of tulsi ghanvati (Ocimum sanctum)

Even though these findings are promising, research on ashwagandha’s potential effects on inflammation is limited at this time.

SUMMARY

Ashwagandha may help reduce inflammatory markers in the body. However, more research is needed.

Taking ashwagandha may benefit cognitive function.

One review that included five clinical studies noted there was early evidence that ashwagandha could improve cognitive functioning in certain populations, including older adults with mild cognitive impairment and people with schizophrenia.

Cognitive functions it may benefit included (21Trusted Source):

• executive functioning
• attention
• reaction time
• performance on cognitive tasks

A study in 50 adults showed that taking 600 mg of ashwagandha extract per day for 8 weeks led to significant improvements in the following measures compared with taking a placebo (22Trusted Source):

• immediate and general memory
• attention
• information-processing speed

Researchers note that compounds found in ashwagandha, including WA, have antioxidant effects in the brain, which may benefit cognitive health (22Trusted Source).

However, more research is needed before experts can draw strong conclusions.

SUMMARY

Ashwagandha supplements may improve memory, reaction time, and the ability to perform tasks in certain populations. However, more research is needed.

Many people take ashwagandha to promote restful sleep, and some evidence suggests it may help with sleep issues.

For example, a study in 50 adults ages 65–80 found that taking 600 mg of ashwagandha root per day for 12 weeks significantly improved sleep quality and mental alertness upon waking compared with a placebo treatment (23Trusted Source).

Additionally, one review of five high quality studies found that ashwagandha had a small but significant positive effect on overall sleep quality.

Taking ashwagandha reduced people’s anxiety levels and helped them feel more alert when they woke up (24Trusted Source).

The researchers noted that results were more pronounced in people with insomnia and in those who took more than 600 mg daily for 8 weeks or longer (24Trusted Source).

SUMMARY

Recent evidence suggests that ashwagandha may be an effective natural remedy to improve sleep and may especially help people with insomnia.

Ashwagandha is a safe supplement for most people, although its long-term effects are unknown.

A review of 69 studies found that ashwagandha root appears to be safe and effective for managing certain health conditions, including stress, anxiety, and insomnia (1Trusted Source).

One study in 80 healthy men and women showed that taking 600 mg of ashwagandha daily for 8 weeks was safe and did not cause any adverse health effects in participants (25Trusted Source).

However, certain people should not take it. For example, pregnant people should avoid it because it may cause pregnancy loss if used in high doses (26).

Also, those with hormone-sensitive prostate cancer and those taking certain medications, such as benzodiazepines, anticonvulsants, or barbiturates, should avoid taking ashwagandha (26).

Some side effects have been reported in people taking ashwagandha supplements, including upper gastrointestinal discomfort, drowsiness, and diarrhea (26).

Additionally, ashwagandha may affect the thyroid, so those with thyroid disease should check with a healthcare professional before taking it (27Trusted Source).

Dosing recommendations for ashwagandha vary. For example, doses ranging from 250–1,250 mg per day have been shown to be effective for different conditions. Consult a healthcare professional if you have questions regarding ashwagandha dosing.

Research findings suggest that ashwagandha’s effects aren’t immediate, so keep in mind that you may have to take it for several months before you start noticing its effects.

You can take ashwagandha in many ways, in either a single dose or multiple doses per day. And you can take it either with meals or on an empty stomach.

Several supplement manufacturers produce it and various retailers sell it, including health food stores and vitamin shops.

SUMMARY

Although ashwagandha is safe for most people, it’s not safe for everyone. It’s important to check with a healthcare professional before taking ashwagandha.

Ashwagandha is an ancient medicinal herb with multiple possible health benefits.

Study findings suggest that it may help reduce anxiety and stress, support restful sleep, and even improve cognitive functioning in certain populations.

Ashwagandha is considered relatively safe for most people. However, it’s not appropriate for everyone, so it’s important to talk with a healthcare professional before adding ashwagandha to your routine.