Ashwagandha, scientifically known as Withania somnifera, is one of the best-known herbs in Ayurvedic medicine and has attracted growing interest in modern wellness and sports nutrition. Traditionally used for thousands of years, ashwagandha is commonly described as an adaptogenic herb—a plant believed to help the body respond to physical and psychological stress.
Today, ashwagandha supplements are widely marketed for stress management, sleep, cognitive performance, exercise recovery, testosterone and general wellbeing. But how much of this is actually supported by scientific research?
The answer is more nuanced than many supplement advertisements suggest.
Clinical research has found promising evidence for some uses, particularly stress and sleep, while evidence for several other popular claims remains limited or inconsistent. The type of extract, dose, treatment duration and characteristics of the individual taking it can also influence the results. The U.S. National Center for Complementary and Integrative Health (NCCIH) notes that many clinical studies have used different ashwagandha preparations and relatively small sample sizes, making it difficult to generalise results to every supplement on the market.
This guide looks at what ashwagandha is, its potential benefits, how it is commonly used, possible side effects, dosage considerations and the important safety questions you should understand before adding it to your daily routine.
What Is Ashwagandha?
Ashwagandha is an evergreen shrub belonging to the Solanaceae family. Its scientific name is Withania somnifera. The plant is native to parts of India and has also been found in regions of Africa and the Middle East.
The roots have traditionally been used in Ayurvedic medicine, although modern supplements may contain root extracts, leaf extracts or combinations of both. Ashwagandha contains several biologically active compounds, including a group known as withanolides.
The name “ashwagandha” comes from Sanskrit and is commonly interpreted as referring to the characteristic smell of the plant’s root and its traditional association with strength and vitality.
It is sometimes called “Indian ginseng”, but this does not mean it is botanically related to ginseng. Ashwagandha belongs to a completely different plant genus.
What Are Withanolides?
Withanolides are naturally occurring compounds found in Withania species and are among the most studied constituents of ashwagandha.
Researchers have investigated these compounds for a variety of biological activities, including antioxidant, anti-inflammatory and stress-related effects. However, evidence from laboratory and animal research should not automatically be interpreted as proof that the same effect occurs in humans.
This distinction is particularly important when evaluating supplement claims.
Different commercial products can also contain different concentrations of withanolides. Therefore, saying that “ashwagandha” has a particular effect without specifying the preparation can sometimes be misleading.
Potential Benefits of Ashwagandha
1. May Help Reduce Stress
Stress management is currently one of the most researched potential uses of ashwagandha.
Several randomised controlled trials have investigated whether ashwagandha supplementation can influence perceived stress and physiological markers such as cortisol. A 2024 systematic review and meta-analysis included nine randomised controlled trials involving 558 participants and reported improvements in measures including perceived stress, anxiety scores and serum cortisol compared with placebo. However, the researchers also noted the need for additional research into long-term safety.
More recent evidence illustrates why the subject should not be oversimplified. A systematic review published in 2025 found a statistically significant reduction in cortisol but did not find a significant improvement in perceived stress scores. This suggests that a change in a biological marker does not necessarily translate into a noticeable improvement in how stressed a person feels.
What does this mean in practice?
Ashwagandha may help some people manage stress, but it should not be presented as a guaranteed treatment for chronic stress, anxiety disorders or other mental health conditions.
It is also not a replacement for professional medical care when significant psychological symptoms are present.
2. May Support Sleep Quality
Sleep is another area in which the evidence is relatively promising.
Some clinical studies suggest that ashwagandha may improve aspects of sleep, particularly in people experiencing sleep difficulties. NCCIH currently reports that some ashwagandha preparations may be helpful for insomnia and stress.
The possible relationship between ashwagandha and sleep may be partly connected to its effects on stress and relaxation. If stress contributes to difficulty falling asleep or maintaining sleep, reducing stress may indirectly support better sleep.
However, this does not mean that ashwagandha should be considered a universal sleep treatment.
Persistent insomnia can have many causes, including sleep disorders, medications, anxiety, depression, caffeine consumption, irregular sleep schedules and underlying medical conditions.
3. May Support Exercise Performance
Ashwagandha has become increasingly popular in sports nutrition and bodybuilding.
Some clinical trials have reported improvements in measures such as strength, muscle-related outcomes and physical performance among people participating in resistance training. However, NCCIH currently considers the evidence for athletic performance insufficient to draw firm conclusions across the wider population.
This is an important distinction.
It is reasonable to say that some research suggests a potential benefit for exercise performance, but it is not scientifically accurate to claim that ashwagandha automatically increases strength, muscle mass or endurance in everyone who takes it.
Training quality, nutrition, protein intake, sleep, recovery and overall programme design remain much more established factors in physical performance.
4. May Have Effects on Testosterone and Male Reproductive Health
Ashwagandha is frequently marketed as a “natural testosterone booster”. The scientific evidence is more limited than this marketing language suggests.
According to NCCIH, there is some limited evidence that taking ashwagandha for approximately two to four months may increase testosterone levels and sperm quality in certain men.
However, this does not mean that everyone taking ashwagandha will experience a meaningful testosterone increase.
Results may depend on the population studied, the formulation used, the dosage and the individual’s baseline health.
Therefore, it is better to describe ashwagandha as a supplement that may influence certain reproductive and hormonal markers in some men, rather than guaranteeing a testosterone boost.
5. May Support Cognitive Function
Ashwagandha is also promoted for memory, focus and mental performance.
Laboratory research has identified several potentially neuroprotective mechanisms associated with compounds found in the plant. Human studies have also investigated memory, attention and cognitive performance.
However, the current evidence is not strong enough to conclude that ashwagandha reliably improves cognitive function in healthy adults or treats cognitive disorders. NCCIH specifically notes that there is not enough high-quality evidence to determine whether ashwagandha is beneficial for cognitive function.
This is an excellent example of why supplement marketing and scientific evidence should be considered separately.
A promising biological mechanism does not automatically equal a proven clinical benefit.
6. Antioxidant and Anti-Inflammatory Properties
Ashwagandha contains compounds that have demonstrated antioxidant and anti-inflammatory activity in laboratory research. Withanolides are among the compounds investigated for these biological effects.
Oxidative stress and chronic inflammation are involved in numerous physiological processes and diseases. This has led to considerable scientific interest in plants with antioxidant and anti-inflammatory properties.
However, it is important not to make the leap from “ashwagandha contains compounds with antioxidant activity” to “ashwagandha prevents cancer, heart disease or other chronic diseases.”
At present, there is not sufficient high-quality human evidence to recommend ashwagandha as a treatment or preventive therapy for these diseases.
7. What About Heart Health and Blood Pressure?
Ashwagandha has also been investigated for cardiovascular-related outcomes, including blood pressure and metabolic markers.
Some studies have reported potentially beneficial changes, but the evidence is not sufficiently established for ashwagandha to be considered a treatment for hypertension, high cholesterol or cardiovascular disease.
This point is particularly important because herbal supplements can sometimes interact with prescription medicines.
For example, NCCIH notes that ashwagandha may interact with medications used for high blood pressure, diabetes, immune suppression, sedation, seizures and thyroid hormone replacement.
Therefore, someone taking medication for blood pressure or another chronic condition should not add ashwagandha without first discussing it with a healthcare professional.
How Does Ashwagandha Work?
The exact mechanisms of ashwagandha are still being investigated.
Its biological activity appears to involve multiple compounds and pathways rather than one single mechanism.
Researchers have investigated its potential influence on:
- Stress-related physiological pathways
- Cortisol
- Inflammatory signalling
- Oxidative stress
- Neurotransmitter systems
- Thyroid-related hormones
- Reproductive hormones
- Immune function
This complexity is one reason why the term adaptogen is often used when discussing ashwagandha.
However, “adaptogen” is a traditional and pharmacological concept rather than a guarantee that the herb will normalise every aspect of the body’s stress response.
Ashwagandha Dosage: How Much Should You Take?
There is no single universally established dose of ashwagandha that applies to every person or every product.
This is because commercial supplements can differ substantially in:
- Plant part used
- Root versus leaf extract
- Extraction method
- Withanolide concentration
- Standardisation
- Serving size
- Formulation
Clinical studies have used different preparations and doses.
A 2026 systematic review focusing specifically on standardised root-only extracts in generally healthy adults identified studies using approximately 125–600 mg per day, with intervention periods ranging from a single dose to 180 days. The review found no clinically meaningful adverse changes in several monitored biomarkers among the studied healthy participants, although this does not establish long-term safety for everyone.
For this reason, consumers should not assume that “600 mg of one extract” is equivalent to “600 mg of another extract.”
Should Ashwagandha Be Taken With Food?
There is no universal requirement that ashwagandha must be taken with food.
However, some people may find taking it with a meal easier on the stomach, particularly if they experience nausea or digestive discomfort.
Always follow the instructions provided by the specific supplement manufacturer.
Ashwagandha Side Effects
Although many people tolerate ashwagandha without major problems, it is not completely risk-free.
NCCIH reports possible side effects including:
- Drowsiness
- Stomach upset
- Diarrhoea
- Vomiting
It also states that short-term use, up to around three months, may be safe for some people, while there is insufficient information to determine its long-term safety.
This is why “natural” should never be interpreted as “risk-free”.
Can Ashwagandha Affect the Liver?
This is one of the most important safety issues to understand.
Although clinically significant liver injury appears to be uncommon, multiple case reports and clinical reviews have associated ashwagandha supplements with liver injury.
A 2026 scoping review identified 25 patients across 13 publications involving suspected ashwagandha-associated liver injury. Liver injury commonly developed after several weeks of use, and cholestatic or mixed patterns were frequently reported. Most patients recovered after stopping the product, but severe cases have also been documented.
Earlier clinical research from India also documented cases of liver injury associated with single-ingredient ashwagandha products, including severe outcomes among individuals with pre-existing chronic liver disease.
When Should You Stop Taking Ashwagandha?
Anyone taking an ashwagandha supplement who develops symptoms such as:
- Yellowing of the skin or eyes
- Dark urine
- Unusual itching
- Persistent nausea
- Significant abdominal discomfort
- Unexplained severe fatigue
should stop the supplement and seek medical advice promptly.
These symptoms can have many causes, but liver-related symptoms should not be ignored.
Who Should Avoid Ashwagandha?
Certain groups should be particularly cautious.
According to NCCIH, ashwagandha should be avoided during pregnancy and breastfeeding. It is also not recommended for people with autoimmune or thyroid disorders, people preparing for surgery, and individuals with certain hormone-sensitive conditions.
People with liver disease should also discuss its use with a healthcare professional, especially given the accumulating reports of supplement-associated liver injury.
Anyone taking prescription medication should also check for potential interactions before starting supplementation.
Ashwagandha and Medication Interactions
Ashwagandha may interact with certain medicines.
Potential interaction categories include:
- Blood pressure medications
- Diabetes medications
- Sedatives
- Immunosuppressants
- Anti-seizure medications
- Thyroid hormone medications
These interactions do not mean that everyone taking one of these medicines will experience a problem. They mean that combining the substances should be evaluated by a healthcare professional.
This is especially important when a person takes several medications simultaneously.
How to Choose a Quality Ashwagandha Supplement
Not all ashwagandha supplements are identical.
When choosing a product, look for clear information about:
1. The plant part
Check whether the product contains:
- Root extract
- Leaf extract
- Root and leaf extract
This matters because different plant parts can have different chemical profiles.
2. Standardisation
A reputable product should clearly state the amount or percentage of key compounds, such as withanolides, when applicable.
3. Ingredient transparency
The label should clearly identify:
- Ashwagandha amount per serving
- Type of extract
- Standardisation information
- Other active ingredients
- Recommended serving
- Manufacturer information
4. Quality testing
Third-party testing and appropriate quality-control procedures can provide additional confidence in product identity, purity and consistency.
This is particularly relevant because the quality of herbal supplements can vary between manufacturers.
Ashwagandha Root vs Leaf Extract
One of the most overlooked details when comparing ashwagandha products is the plant part used.
Traditional preparations have commonly involved the root, while some modern supplements use root-and-leaf or leaf-containing extracts.
Because clinical trials use specific preparations, their findings cannot automatically be applied to every formulation containing Withania somnifera.
For consumers, the practical lesson is simple:
Do not compare products based only on the number of milligrams on the front of the bottle.
A lower dose of a concentrated, standardised extract is not necessarily equivalent to a higher dose of an unstandardised powder.
How Long Does Ashwagandha Take to Work?
There is no universal timeline.
Some studies have evaluated outcomes after several weeks, while others have followed participants for a few months.
For stress and sleep-related outcomes, clinical studies often examine changes over multiple weeks rather than expecting an immediate effect.
More importantly, individual responses can vary considerably.
If someone does not notice a meaningful benefit after an appropriate period, taking increasingly larger amounts is not necessarily the answer.
Long-term safety remains an area where more research is needed.
Is Ashwagandha Safe for Daily Use?
For many healthy adults, short-term use of appropriately prepared ashwagandha appears to be reasonably well tolerated.
However, “safe for daily use” should not be interpreted as “safe indefinitely.”
NCCIH notes that evidence is currently insufficient to establish long-term safety.
More recent research has also highlighted the need for continued monitoring of possible liver, endocrine and immune-related effects.
The safest approach is to use a clearly labelled product according to its directions and seek professional advice if you have a medical condition or take medication.
Frequently Asked Questions About Ashwagandha
What is Ashwagandha used for?
Ashwagandha is traditionally used for general vitality and wellbeing and is now commonly marketed for stress, sleep, exercise performance and hormonal health. Scientific evidence is strongest or most promising for some stress- and sleep-related outcomes, while evidence for several other uses remains limited.
Does Ashwagandha reduce cortisol?
Some clinical trials and meta-analyses have reported reductions in cortisol. However, newer evidence suggests that a reduction in cortisol does not necessarily correspond to a significant improvement in perceived stress.
Does Ashwagandha help with sleep?
Some evidence suggests that certain ashwagandha preparations may improve sleep, particularly in people experiencing sleep difficulties. However, it should not be considered a replacement for proper assessment and treatment of persistent insomnia.
Does Ashwagandha increase testosterone?
There is limited evidence that some men may experience increased testosterone after several months of supplementation, but it is not guaranteed and should not be marketed as a universal testosterone booster.
Can women take Ashwagandha?
Ashwagandha is used by both men and women, but pregnancy and breastfeeding are important exceptions. NCCIH recommends avoiding it during pregnancy and breastfeeding. People with thyroid or autoimmune disorders should also seek medical advice before use.
Can Ashwagandha cause side effects?
Yes. Possible side effects include digestive upset, diarrhoea, vomiting and drowsiness. Rare but potentially serious liver injury has also been reported.
Is Ashwagandha a medicine?
Ashwagandha is a medicinal plant traditionally used in Ayurveda, but an ashwagandha dietary supplement should not automatically be considered equivalent to a prescription medicine or clinically proven treatment.
The Bottom Line: Is Ashwagandha Worth Taking?
Ashwagandha is an interesting herbal supplement with a long history of traditional use and a growing body of modern research.
The strongest current discussion centres around stress management and sleep, with some evidence also suggesting possible effects on testosterone, reproductive parameters and exercise-related outcomes. However, the evidence varies substantially depending on the preparation and population studied.
At the same time, it is important to avoid exaggerated claims.
Ashwagandha is not a guaranteed treatment for anxiety, insomnia, high blood pressure, cancer, diabetes or other chronic diseases. Nor should it automatically replace medical treatment.
Safety deserves equal attention. Most healthy adults appear to tolerate short-term supplementation reasonably well, but long-term safety remains uncertain, and rare cases of clinically significant liver injury have been reported.
For consumers, the best approach is therefore straightforward:
Choose a transparent, appropriately standardised product, follow the recommended serving, avoid assuming that higher doses are better, and speak with a qualified healthcare professional if you take medication, have an underlying medical condition, are pregnant or breastfeeding, or plan to use ashwagandha for an extended period.
Ashwagandha may have a useful place in a broader wellness routine, but its benefits should be judged by the quality of the evidence—not by the strongest claim on a supplement label.
Medical Disclaimer: This article is provided for general educational purposes only and is not intended to diagnose, treat, cure or prevent any disease. Dietary supplements can interact with medicines and may not be appropriate for everyone. Consult a qualified healthcare professional before starting ashwagandha, particularly if you have an existing medical condition, take prescription medicines, are pregnant or breastfeeding, or are considering long-term use.