Ashwagandha: What Is It and What Does the Research Say?

Ashwagandha has moved quickly from traditional herbal medicine into mainstream supplements.

You will now find it in capsules, powders, drinks and gummies, often marketed for stress, sleep, mood, energy, hormones and focus.

Some of those ideas have been studied in people. Others are much less certain.

The useful approach is to separate what is interesting from what has actually been established.

The short version

Ashwagandha, or Withania somnifera, is a plant with a long history of use in Ayurvedic traditions.

Modern research has focused particularly on stress and sleep. Some clinical trials and systematic reviews have found improvements in measures of stress, anxiety or sleep with certain ashwagandha extracts, but studies have often been relatively small and have used different preparations and doses.

That means the research is promising, but it does not justify treating ashwagandha as a proven treatment for stress, anxiety, insomnia or other health conditions.

Short-term use appears to be tolerated by many adults, but there is less information about long-term safety. Ashwagandha is not suitable for everyone and can interact with medicines.

UK regulators are also reviewing its safety, including possible effects involving the liver, thyroid and blood glucose.

What is ashwagandha?

Ashwagandha is an evergreen shrub found in parts of India, Africa and the Middle East.

Its botanical name is Withania somnifera.

Different parts of the plant have historically been used in traditional medicine, particularly Ayurveda. Modern food supplements commonly use extracts of the root, the leaf, or combinations of plant material.

Ashwagandha contains a range of naturally occurring compounds, including a group called withanolides.

You will often see the word adaptogen used alongside ashwagandha.

Adaptogen is a term used for plants or substances proposed to help the body respond to stress. It is useful as a description of how ashwagandha is commonly discussed, but the word itself is not evidence that a product will reduce stress or improve health.

What does the research say about stress?

Stress is probably the area where ashwagandha has received the most attention.

A 2024 systematic review and meta-analysis looked at nine randomised controlled trials involving 558 participants. It found improvements in some measures of perceived stress, anxiety and cortisol compared with placebo, although the studies used different preparations and further safety information was considered necessary.

Research published since then has not made the picture completely straightforward.

A 2025 meta-analysis found a reduction in cortisol but did not find a clear effect on perceived stress, while a larger 2026 review reported promising improvements in stress, anxiety and depressive symptoms but concluded that better-quality trials are still needed because the existing research is heterogeneous.

So there is a genuine research signal here.

But "some trials show an effect" and "ashwagandha reliably treats stress" are not the same statement.

What about sleep?

Sleep is another area where the evidence is interesting.

A systematic review of five randomised trials involving 400 adults found a modest overall improvement in sleep with ashwagandha extract. Effects appeared greater in participants with insomnia and in some studies using longer durations and higher doses.

A later review looking at anxiety and insomnia also found promising results, while noting that the available trials were limited and that larger studies are still needed.

That makes sleep worth researching further.

It does not mean ashwagandha should replace proper assessment of persistent insomnia, particularly when poor sleep may be related to stress, medication, sleep apnoea, mental health, lifestyle or another underlying problem.

Does ashwagandha balance hormones?

This is where marketing often becomes much broader than the evidence.

Ashwagandha has been studied in relation to cortisol, thyroid hormones, testosterone and reproductive health.

A 2026 systematic review found changes in some hormone measures, including cortisol and testosterone in men, but results varied and the authors highlighted substantial differences between studies.

That is not the same as showing that ashwagandha "balances hormones".

Hormones are not one system that can simply be moved into balance by a supplement. Different hormones have different functions, and abnormal hormone levels can have medical causes that require proper investigation.

I would be cautious of any supplement marketed broadly as a solution for "hormonal balance".

What about focus, energy and athletic performance?

These areas have also attracted interest, but the evidence is less established.

The US National Center for Complementary and Integrative Health notes that there is not currently enough evidence to determine whether ashwagandha is helpful for areas including cognitive function and athletic performance.

This is a good example of why one ingredient can accumulate a very long list of supposed benefits online.

A plausible mechanism or an early study can be interesting, but it should not automatically become a consumer promise.

Are all ashwagandha supplements the same?

No.

Studies have used different plant parts, extracts, extraction methods, concentrations and doses.

A study using one particular root extract cannot automatically prove that every product labelled "ashwagandha" will have the same effect.

This is especially important when comparing a dried plant powder with a concentrated extract.

An extract ratio such as 10:1 or 30:1 describes how the ingredient was produced, but it does not by itself tell you how clinically effective the final supplement will be.

Similarly, a higher number on the label does not automatically make a product better.

Is ashwagandha safe?

Many people appear to tolerate ashwagandha in the short term, but that does not mean it is suitable for everybody.

Reported side effects can include stomach upset, diarrhoea, vomiting and drowsiness. There have also been uncommon reports linking ashwagandha supplements with liver injury. Long-term safety is less well understood.

Ashwagandha should be avoided during pregnancy and is not recommended while breastfeeding. It is also not recommended for people who are about to have surgery or who have certain thyroid or autoimmune conditions.

There may also be interactions with medicines used for diabetes, blood pressure, seizures, thyroid conditions, sedation and suppression of the immune system.

If you take regular medication or have an existing medical condition, it is sensible to check with an appropriate healthcare professional before using it.

Why are UK regulators reviewing ashwagandha?

The Food Standards Agency began gathering evidence after concerns were raised about the safety of ashwagandha supplements.

Areas under review include possible effects involving thyroid hormones, blood glucose and the liver. The FSA has said that no safe level for ashwagandha in food supplements has yet been established in the UK.

The Committee on Toxicity has been reviewing the evidence, and its work remains ongoing in 2026.

That does not mean ashwagandha has suddenly been shown to be unsafe.

It means there are still questions that regulators are working through.

For us, that is a reason to be more careful with the ingredient, not a reason to ignore either the research or the uncertainty.

A note about Khan Nutrition Ashwagandha Gummies

Our Ashwagandha Gummies use an ashwagandha root extract in a raspberry-flavoured gummy format.

The directions are two gummies daily.

They are intended for adults and are suitable for vegetarians and vegans. They are halal.

We do not present them as a treatment for anxiety, insomnia, hormonal problems or any other medical condition.

If you are pregnant or breastfeeding, take regular medication, have a thyroid or autoimmune condition, have concerns about your liver, or are preparing for surgery, ashwagandha may not be appropriate for you.

Explore Ashwagandha Gummies

What is worth remembering?

Ashwagandha is more interesting than either extreme suggests.

It is not fair to dismiss it simply because it is a traditional herbal ingredient. There are human trials suggesting potentially useful effects, particularly around stress and sleep.

But it is equally unhelpful to turn those early and mixed findings into promises about stress relief, hormones, energy, focus, immunity, fitness and general wellbeing all at once.

The current evidence is promising in some areas and uncertain in others.

Safety matters too, particularly because ashwagandha is biologically active and may not be appropriate for everyone.

That makes it an ingredient worth following with interest rather than one that needs hype.

Sources and further reading

Food Standards Agency: Ashwagandha
The FSA's evidence review and explanation of the current UK safety assessment.
Read the FSA information

Committee on Toxicity: Ashwagandha safety review
Current information on the ongoing UK review of ashwagandha in foods and supplements.
Read the Committee on Toxicity update

NCCIH: Ashwagandha
Overview of current research, side effects, medicine interactions and safety considerations.
Read the NCCIH overview

PubMed: Ashwagandha, stress and anxiety systematic review
A 2024 systematic review and meta-analysis of randomised controlled trials.
View the research

PubMed: Ashwagandha and sleep systematic review
A systematic review and meta-analysis of randomised trials examining sleep outcomes.
View the sleep research

Last reviewed: September 2026