Ashwagandha is a herbal supplement, not a proven performance aid. Some small studies suggest it may help with stress, sleep, or strength gains, but the evidence is early, mixed, and nowhere near strong enough to support the confident claims made on a lot of product pages – and it has no EU-authorised health claim at all.
What ashwagandha is and why athletes take it
Ashwagandha (Withania somnifera) is a root used for centuries in Ayurvedic medicine, sold today mostly as a standardised root extract in capsule or powder form, often labelled by a specific extract name and standardisation percentage rather than sold as a raw powder. Athletes take it hoping it will lower stress, improve sleep quality, or add a bit extra to strength and recovery. It has become one of the fastest-growing categories in the supplement aisle over the last few years, largely on the back of marketing and social media rather than a settled body of evidence, which is exactly why it’s worth separating what’s actually been tested from what’s simply been repeated often enough to sound true.
What the research shows on stress and sleep
A handful of small randomised trials have looked at ashwagandha extract and measures of perceived stress or sleep quality, generally over 8-12 weeks. Some report modest improvements in stress questionnaires and sleep scores compared with placebo. But most of these trials are small, often run or funded by supplement manufacturers, use different extracts and doses, and rely on subjective self-reported scores rather than objective measures. That combination makes it hard to separate a genuine effect from placebo response, expectation, or simply reporting bias in an unblinded-feeling trial.
- Early and mixed, not settled – a few positive small trials do not add up to strong evidence, especially without independent replication.
- Nothing here supports a claim that ashwagandha treats anxiety or a sleep disorder – it is a supplement, not a medicine.
What the research shows on strength and performance
Ashwagandha has also been studied for strength training outcomes, with some small trials in resistance-trained men reporting slightly greater gains in strength or muscle size compared with placebo over 8-12 weeks. Other trials find no meaningful difference. Study quality varies widely, sample sizes are small, and results have not been consistently replicated across independent labs. It is not established as an ergogenic aid for endurance performance, and there is no good evidence it raises testosterone in any meaningful, reliable way – a claim frequently repeated in marketing copy that outruns what the trials actually show.
- Possible small effect on strength training outcomes in some studies – but inconsistent and unproven as a general rule.
- No credible evidence it meaningfully raises testosterone or directly boosts endurance performance.
Safety and interactions
Ashwagandha appears to be reasonably well tolerated in most short-term studies, with mild digestive upset the most commonly reported issue. It is not appropriate for everyone, though: it may interact with thyroid medication, sedatives, and immunosuppressants, and it is not recommended during pregnancy or for people with autoimmune conditions or certain liver issues. Most trials only run 8-12 weeks, so long-term safety data beyond that window is limited, and rare reports of liver problems linked to ashwagandha products have appeared in the medical literature, usually in case reports rather than controlled trials. As with any herbal supplement, check with a GP or pharmacist before starting it if you take regular medication or have an existing health condition.
Why there’s no EU health claim
Under EU law, a health claim on a supplement label can only be made if it has been formally assessed and authorised – most botanical ingredients, including ashwagandha, currently have no authorised health claim in the EU register at all. That is not a technicality; it reflects that the evidence base, as it stands, has not met the bar regulators require before allowing a company to state a specific health benefit as fact. Any product claiming ashwagandha “reduces stress” or “boosts testosterone” as an established fact is going further than the science, and further than EU rules allow.
The marketing versus the evidence
This is the honest part: ashwagandha’s marketing is well ahead of its evidence. Search interest and sales have grown enormously, driven largely by social media claims about stress relief, better sleep, and testosterone, none of which are backed by strong, consistent, independently replicated trials. That doesn’t mean the ingredient is useless or dangerous – it means “promising but unproven” is the accurate description, not “clinically proven” or “backed by science,” phrases that show up constantly on product listings without the trial base to support them. A useful test when reading a product page is to ask whether the claim would survive being rewritten as “some small studies suggest” instead of “proven to” – if the sentence suddenly sounds a lot less impressive, that’s usually the honest version.
Should you take it – the honest bottom line
If you’re generally healthy, not on interacting medication, and curious to try it, ashwagandha is unlikely to cause harm at typical doses used in studies (commonly 300-600mg of a standardised root extract per day). Just go in with realistic expectations: it is not a proven performance supplement, it will not reliably replace addressing poor sleep habits or training stress directly, and any benefit you notice may be real, may be placebo, or may be nothing at all. Basics – sleep, recovery, protein, and training load management – do far more for performance than any herbal extract, and that’s where your money and attention are better spent first.
Source: EU Register of nutrition and health claims, NHS – Herbal medicines.
Frequently asked questions
Does ashwagandha actually work for athletes?
The evidence is early and mixed. Some small studies suggest possible benefits for perceived stress, sleep, or strength training gains, but trials are small, inconsistent, and often not independently replicated. It is not a proven performance supplement, and it has no EU-authorised health claim.
Does ashwagandha boost testosterone?
There is no credible evidence that ashwagandha meaningfully or reliably raises testosterone. This claim appears often in marketing but is not supported by a solid body of independent clinical evidence.
Is ashwagandha safe to take?
It appears reasonably well tolerated in most short-term studies, with mild digestive upset the most common side effect. It may interact with thyroid medication, sedatives, and immunosuppressants, and is not recommended during pregnancy or for people with certain autoimmune or liver conditions - check with a GP or pharmacist first if you take regular medication.
Why doesn't ashwagandha have an EU health claim?
Under EU law, a health claim can only appear on a label if it has been formally assessed and authorised. Ashwagandha, like most botanical ingredients, currently has no authorised health claim in the EU register, reflecting that the evidence has not yet met the bar regulators require.
What dose of ashwagandha is used in studies?
Most clinical trials use somewhere around 300-600mg of a standardised root extract per day, typically over 8-12 weeks. Results at these doses are still inconsistent across studies, so no dose can be described as proven effective.