Ashwagandha, the much-touted ‘adaptogenic’ food supplement, is suddenly everywhere, from the aisles of high street health shops to countless social media posts.
But with a growing list of European countries considering a ban, we investigate whether it’s a safe and proven solution for anxiety, or a possible gamble with your health.
While it might be the latest buzzword in ‘adaptogens’ – supplements believed to help the body adapt to stressors – ashwagandha is about as far from new as it’s possible to get.
Native to regions of Africa, the Middle East and the Indian subcontinent, it has been used in Ayurvedic medicine for centuries.
Does ashwagandha work?
There is some clinical research behind ashwagandha, specifically the root extract.
Several small, double-blind trials have shown that taking between 300mg and 600mg of a standardised extract can lead to a measurable drop in cortisol (often known as the stress hormone). Participants in these studies typically reported lower scores on anxiety scales compared to those taking a placebo.
However, while these results are promising, the studies are small (often involving fewer than 100 people) and run for only 8-12 weeks. Many trials are also funded by the companies that manufacture the extracts.
More work is needed, particularly because scientists have not yet established the impact of taking high doses over longer periods.
Currently, ashwagandha has no authorised health claims in the UK. What’s more, emerging safety warnings from European regulators have raised concerns about the possible health impacts of taking it.
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Is ashwagandha safe? The red flags you need to know
There is often an assumption that things that are ‘natural’ must also be harmless, but that’s not always the case. For example, arsenic is ultimately natural. Plus, the dose/strength of a substance can make a big difference.
The NHS warns that all herbal medicines may potentially interact with other drugs you’re taking, and may also cause bad reactions or side effects.
In the case of ashwagandha, there are potentially significant side effects and interactions that it’s important to be aware of, including possibly liver damage.
In 2024, the UK Food Standards Agency (FSA), which regulates food supplements, launched a ‘call for evidence’ to decide if the UK should restrict ashwagandha sales, based on several other European countries doing the same.
The FSA told us: ‘The COT [Committee on Toxicology, an independent body that advises the FSA on the safety of chemicals] is conducting a review of all available data in evaluating the safety of ashwagandha supplements. This includes effects on thyroid hormone levels and reports of thyroid toxicity, hypoglycaemic effects, and potential liver toxicity.
‘While the review is ongoing, we would advise people with pre-existing liver conditions and pregnant women to avoid ashwagandha supplements.
‘We are not yet able to say whether a direct link exists between ashwagandha and liver injury, but it is sensible to be cautious for those who may be more vulnerable.
‘Some of the data indicate a potential for liver toxicity. The available information is currently being evaluated by the COT for its quality and reliability to determine whether a causal relationship exists between ashwagandha supplementation and liver toxicity.’
The FSA has a guide on food supplement safety, which provides important information on buying them and what to do if you feel unwell after taking a supplement.
The NHS also has useful advice for those considering herbal medicines, including medicines that commonly don’t mix well with them, such as anti-depressants, diabetes meds, blood pressure or blood-thinning meds and statins.
Why you need to be careful with ashwagandha
The potential risks of taking it are currently being investigated, and include:
Liver issues: Several European countries, including Denmark, have raised alarms over rare but serious cases of liver toxicity linked to ashwagandha.
Thyroid impact: There is some evidence that ashwagandha can increase thyroid hormone levels. That means for anyone taking medication for an underactive thyroid, or for those with hyperthyroidism, it’s crucial to consult a doctor before taking it.
Autoimmune risks: Because ashwagandha may stimulate the immune system, it could worsen conditions like lupus, multiple sclerosis, or rheumatoid arthritis. Again, it’s very important to consult a doctor if this applies to you and you are considering taking it.
Pregnancy warning: Ashwagandha should not be taken during pregnancy. In very high doses, it may cause miscarriage, and there isn’t enough evidence for its safety in lower doses.
It may also interfere with some medications.
However, there is some debate over the quality of the research behind some of these concerns, and more research is needed to establish safety. For now, exercising caution and following the FSA guidance on who should avoid it is sensible.
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What to consider if buying ashwagandha
If you’ve weighed the risks and still want to try ashwagandha, take care to buy from a reputable brand that is transparent about its quality assurance processes.
Look out for the Traditional Herbal Registration (THR) logo. The Medicines and Healthcare Products Regulatory Agency (MHRA) runs this scheme to ensure that herbal medicines have gone through a rigorous application process.
Also look for labels that mention the percentage of withanolides (the active compound in ashwagandha). If a brand doesn’t list this, you have no way of knowing how potent the extract actually is.
And do talk to a health professional first, especially if you have any pre-existing conditions or are taking medication.
Our verdict on ashwagandha
The Committee on Toxicity (COT) is currently finalising a formal safety statement on ashwagandha, expected later this year.
For now, given the lack of long-term safety data and the current uncertainty, it’s best to proceed with caution – or preferably hold off for now.
Don’t take it if: You are pregnant, have a liver condition, or an autoimmune disease.
Check with a GP if: You take regular medication or have any existing health conditions, especially thyroid, diabetes, or blood pressure medication.
If you do buy it: Stick to reputable brands and look for root extract, rather than leaf versions.
