Ashwagandha is a traditional stress reliever that is being investigated for potential benefits to memory and immune function, but some people don’t tolerate it well. What do people use it for? What does the science say? Learn more here.
What is Ashwagandha?
Like most supplements, ashwagandha is not approved by the FDA for any purpose. The evidence presented here is considered preliminary and insufficient to justify medical use .
To avoid unexpected interactions or other adverse events, talk to your doctor before incorporating ashwagandha into your daily regimen.
Ashwagandha (Withania somnifera) is a member of the Solanaceae or nightshade family of plants. It goes under several other names, such as Indian ginseng, poison gooseberry, or Indian winter cherry .
The name Ashwagandha can be traced back to ancient Sanskrit. It translates to “smell of a horse” (ashwa “horse” and gandha “smell”) since the scent of its roots is similar to that of horse urine. Others say its name indicates it will make you “strong like a horse,” and there may be truth to this claim [2, 3].
Ashwagandha is a powerful adaptogenic herb. Adaptogens increase the body’s resistance to stress, offsetting detrimental effects and helping to balance bodily functions and the immune response .
- May combat the effects of stress on mind and body
- May stimulate the immune system
- Believed to reduce pain, inflammation, and oxidative damage
- Promising research into potential cognitive and metabolic benefits
- Associated with improved heart, gut, and adrenal health
- Has unpleasant taste
- May increase thyroid hormones
- May cause digestive issues
- Not enough clinical testing to justify medical use
- Insufficient evidence for a lot of claims
- No safe & effective dose has been determined
- The roots are used as a tonic, aphrodisiac, diuretic, antiparasitic, astringent, and stimulant
- The leaves are recommended for fever and painful swelling
- The seeds are antiparasitic while the flowers are used as an astringent, diuretic, and aphrodisiac and have detoxifying effects
- The berries and tender leaves are applied externally to tumors, ulcers, and wounds
- Other useful parts are the stem, fruit, and bark
Ashwagandha root is also used to restore health in women after giving birth and to thicken and increase the nutrition of breast milk. Despite its centuries-long use in India, Ashwagandha has only recently gained scientific recognition in the West [6, 2].
Ashwagandha contains a range of active components, including a unique family of compounds called withanolides, as well as alkaloids, saponins, terpenoids, flavonoids, tannins, phenols, and resins [7, 4].
Among Ashwagandha’s components, the most biologically active are the withanolides, and the best studied is withaferin A. This component has recently become a focus of research because of its ability to hinder the growth of tumors [8, 9, 10].
Withaferin A is a powerful antioxidant and anti-inflammatory withanolide. Researchers are currently investigating whether it could be used to fight glioblastoma, the most common and deadliest brain cancer .
One of the main obstacles to using withaferin A as a therapeutic agent is low bioavailability, meaning that only a small amount of ingested withaferin A makes it into the bloodstream. Some researchers have proposed loading withaferin A into a biodegradable implant to deliver it more effectively to the blood [8, 11].
Potential Benefits of Ashwagandha
Ashwagandha supplements have not been approved by the FDA for medical use and generally lack solid clinical research. Regulations set manufacturing standards for them but don’t guarantee that they’re safe or effective. Speak with your doctor before supplementing.
Possibly Effective For
1) Anxiety & Stress
Of all of the potential benefits of ashwagandha, this has the most robust body of evidence to support it, but it hasn’t been approved by the FDA! It’s important to talk to your doctor before taking ashwagandha for any reason.
Ashwagandha is traditionally used as a tonic to calm the nerves. In two studies of 116 chronically-stressed people, the root extract improved stress, well-being, and happiness; it also reduced cortisol levels [2, 13, 3].
Insufficient Evidence For
The following purported benefits are only supported by limited, low-quality clinical studies. There is insufficient evidence to support the use of ashwagandha for any of the below-listed uses. Remember to speak with a doctor before taking ashwagandha, and never use it in place of something your doctor recommends or prescribes.
3) Fat Loss & Muscle Growth
Ashwagandha root extract reduced food cravings, eating, and body weight in a study of 52 people .
- Reduced body fat
- Increased muscle strength
- Boosted testosterone
- Reduced body fat
In a trial of 49 healthy athletic adults, Ashwagandha extract improved endurance and self-reported physical health after 12 weeks .
It had the same effect on 40 elite cyclists after 8 weeks of supplementation .
In a small trial of 12 people, Ashwagandha decreased blood sugar levels as effectively as diabetes medication, without significant adverse side effects .
In other animal studies, Ashwagandha reduced the severity of complications from diabetes, such as testicular dysfunction, cataracts, and nerve pain. Supplementation also improved antioxidant status; this is helpful because excess glucose creates oxidative stress [33, 34, 35, 36].
6) Heart Health
Ashwagandha is believed to reduce blood pressure and cholesterol and prevent atherosclerosis, thus improving heart health, but clinical evidence is limited. In one human trial, adding ashwagandha to conventional anti-ischemic drugs improved outcomes compared to the conventional treatment alone [31, 37, 38].
In a study of 133 people with tuberculosis, Ashwagandha and other herbals in combination with antibiotics relieved coughing and fever better than antibiotics alone. In another study of 99 people with tuberculosis, Ashwagandha improved symptoms, inflammation, and body weight [42, 43].
An herbal remedy containing Ashwagandha sped up recovery from viral hepatitis in 29 patients .
Ashwagandha inhibited the growth of multiple species of fungus (Aspergillus flavus, Fusarium oxysporum, and Fusarium verticillioides) in a cell study .
8) Symptoms of OCD & ADHD
Ashwagandha also effectively treated the symptoms of OCD in mice .
ADHD is usually treated with psychostimulants, such as Ritalin. However, their long-term safety has been questioned in several studies. A safer alternative would be preferable for many parents [57, 58].
An herbal mix containing Ashwagandha, peony, Gotu Kola, spirulina, bacopa, and lemon balm improved response time, impulsivity, and focus in a study of 120 children with ADHD, with no adverse side effects reported .
No studies have yet investigated the effect of Ashwagandha alone in ADHD.
However, it did not help with feelings of isolation or depression in another study of 25 schizophrenic patients .
Ashwagandha reduced pain, stiffness, and disability in 60 people with knee joint pain. Ayurvedic treatment containing ashwagandha reduced pain, joint tenderness, and swelling in a study of 86 people with rheumatoid arthritis [62, 63].
In another study of 42 people, an herbal mixture containing Ashwagandha, Indian frankincense, turmeric, and zinc reduced pain from osteoarthritis. Ashwagandha also relieved pain in three rodent studies [64, 65, 66, 67].
11) Reproductive Health
Ashwagandha may reduce the complications of menopause. In a trial of 51 menopausal women, ashwagandha reduced symptoms such as hot flashes, mood fluctuations, sleep issues, irritability, and anxiety .
In 50 healthy women, Ashwagandha improved self-reported measures of sexual function such as arousal, lubrication, orgasm, and satisfaction .
In a clinical trial of 150 men, Ashwagandha reduced oxidative stress, increased testosterone, and lowered FSH. These hormonal changes encourage the production of new sperm cells. It also improved sperm count and mobility .
In 46 men with low sperm count, Ashwagandha increased :
- sperm count, by 167%
- semen volume, by 53%
- sperm motility, by 57%
It recovered semen quality in 180 infertile men .
The root or whole plant extract has been used as a sleep agent in Ayurveda. A mouse study found that triethylene glycol is the active component of Ashwagandha responsible for sleep induction .
Sleep loss is unhealthy and leads to increased levels of reactive oxygen species (ROS) and cell death in the brain. Interestingly, Ashwagandha prevented the negative effects of sleep deprivation in rodents, likely through antioxidant mechanisms [77, 78, 79].
In a small trial of 5 people, Ashwagandha extract improved the immune response by activating white blood cells. In two other trials (a total of 142 people), an herbal mix containing Ashwagandha increased the activity of natural killer cells, white blood cells specialized to fight tumors and viruses [80, 81].
Finally, in a combined mouse and cell study, Withaferin A inhibited the activity of myeloid-derived suppressor cells (MDSCs). These dysfunctional immune cells can stimulate tumor growth and prevent the immune system from attacking cancer cells [85, 86].
14) Gut Health
In a single case report, an Ayurvedic medication containing Ashwagandha helped treat constipation, stomach pain, and vomiting .
Note, however, that one animal study and a single case study of an herbal blend cannot be considered strong evidence. We need additional studies before making any definitive claims about Ashwagandha’s effect on the digestive system.
15) Adrenal Function
Congenital adrenal hyperplasia (CAH) is an inborn dysfunction of enzymes that control hormone production in the adrenal gland. It results in a deficiency of cortisol and aldosterone and an excess of male hormones. Symptoms include excess facial hair, acne, hair loss, menstrual irregularity, and infertility.
Controlled trials will be needed to confirm this benefit.
Animal & Cell Research (Lacking Evidence)
No clinical evidence supports the use of ashwagandha for any of the conditions listed in this section. Below is a summary of the existing animal and cell-based research, which should guide further investigational efforts. However, the studies listed below should not be interpreted as supportive of any health benefit.
16) Oxidative Stress
Withanolides, the Ashwagandha active compounds, are potent antioxidants. In a study on human cells, Ashwagandha improved markers of age-related oxidative stress (FOXO3A and SIRT3), suggesting it may prevent premature aging .
In rat studies, Ashwagandha boosted the body’s antioxidants, including superoxide dismutase (SOD), catalase, and glutathione. It also prevented kidney injury due to dehydration and oxidative damage due to chemotherapy [92, 93, 94].
17) Brain Health
Ashwagandha can reduce oxidative damage from drugs and protect against excess glutamate. It helped control epileptic seizures in mice and treat dyskinesia (involuntary movement) in rats [100, 101, 102, 103, 104].
Alzheimer’s disease is a form of dementia caused by deposits of beta-amyloid proteins and loss of brain cells. Ashwagandha improved cognitive function and reduced beta-amyloid deposits in mouse models of Alzheimer’s [105, 106].
Parkinson’s disease is a neurodegenerative disease involving progressive loss of dopamine neurons. In a mouse model of Parkinson’s, Ashwagandha normalized dopamine levels and reduced free radical damage to brain cells [107, 108].
Huntington’s disease is a genetic disorder that causes oxidative damage and a progressive breakdown of brain cells .
18) Bone Health
Bone health issues often arise after menopause, when low levels of estrogen disrupt bone structure. In mice with estrogen deficiency, Ashwagandha prevented bone loss and stimulated new bone formation [112, 113].
19) Kidney Damage
In rat studies, Ashwagandha protected the kidneys against toxicity of several chemicals, including:
- Bromobenzene (toxic chemical) 
- Carbendazim (antifungal) 
- Gentamicin (antibiotic) [122, 123]
- Lead (heavy metal) 
- Streptozotocin (chemotherapy) 
It also protected against kidney damage caused by dehydration .
20) Liver Health
21) Respiratory Health
In baby rats, withaferin A also protected the lungs against inflammation and oxidative stress caused by toxic bacterial lipopolysaccharides (LPS). Future trials will clarify whether Ashwagandha or its compounds may be helpful against respiratory infections .
Lupus is an autoimmune disease that involves high levels of inflammation. In a mouse study, Ashwagandha reduced inflammatory markers that tend to be high in lupus and other autoimmune diseases, including IL-6 and TNF-alpha [132, 133].
23) Traditional Use as a Venom Antidote
24) Morphine Dependence
Ashwagandha may help prevent people from developing a dependence on morphine, and it may help people who are already dependent wean themselves off of morphine without severe withdrawal symptoms .
In a rat study, Ashwagandha extract reduced withdrawal symptoms and prevented morphine dependence. In neurons exposed directly to morphine, Ashwagandha extract prevented the downregulation of opioid receptor activity. Thus, Ashwagandha may be useful to prevent dependence when opioid painkillers are necessary [137, 138, 136].
25) Mild Hypothyroidism
Mild hypothyroidism, or low thyroid hormones, occurs in 3-8% of people and is especially common in women over 55. Treatment with levothyroxine, a synthetic form of the thyroid hormone T4, often comes with more risks than benefits; thus, many people with mild hypothyroidism go untreated .
Ashwagandha improved fatigue and quality of life in a trial of 100 cancer patients receiving chemotherapy .
In cell and animal studies, Ashwagandha has slowed or reversed the growth of several cancers, including:
- Brain [149, 150]
- Breast [151, 152, 153]
- Cervical [154, 154]
- Colon [155, 150]
- Kidney 
- Lung [2, 157]
- Lymphoma 
- Ovarian 
- Pancreatic 
- Prostate [150, 160]
- Skin [161, 162, 163, 2]
- Stomach 
How to Use Ashwagandha
There is no safe and effective dose of ashwagandha because no sufficiently powered study has been conducted to find one.
Root extract: most clinical studies have used 120-1000 mg daily, with the most common dose being 300 mg twice daily.
Whole root: clinical doses range between 2-10 g of powdered root daily, with an average of 5 g per day.
Safety & Side Effects
Ashwagandha is generally safe when taken in recommended dosages. Large doses of Ashwagandha can cause abdominal discomfort and diarrhea. Because Ashwagandha is mildly sedative, be careful about taking other sedatives with it.
Ashwagandha is available in many forms, such as powder, capsules, pills, or essential oil. It can also be made into a tea or ointment using honey or ghee. Commercial Ashwagandha is often combined with black pepper extract, another strong antioxidant.
In Ayurveda, the fresh roots are sometimes boiled in milk prior to drying to leach out undesirable components .
Taste & Smell
Ashwagandha is a famously pungent herb. Its name means “smell of horse”, and some users say it can be overwhelming. If you are concerned about the smell and taste of Ashwagandha but still want to try it, look for capsules of dry extracts [3, 2].
Ashwagandha is a powerful and versatile traditional herb known for its ability to relieve anxiety and stress. Its active components have been investigated for cognitive and emotional benefits; they may also help manage neurological conditions from Alzheimer’s to schizophrenia.
The antioxidant properties of ashwagandha prevent tissue damage in the liver, lungs, brain, and kidneys. It also prevents hormonal imbalances and improves sexual function in both men and women. Ashwagandha is safe and effective at daily doses of up to 1000 mg of root extract or 10 g of powdered root.
For the best results, start with low doses and work your way up, take a high-quality standardized supplement, and do your best to reduce stress. Ashwagandha should not be taken with other sedatives or by people with high thyroid hormones.