KSM-66 Ashwagandha: What It Is, Dose, and How It Compares (UK)

Last updated: October 2026

KSM-66 is a branded ashwagandha extract made by Ixoreal Biomed from the root only, without alcohol or chemical solvents, and standardised to at least 5% withanolides. Most KSM-66 trials gave 300mg twice a day (600mg in total) for 8 to 10 weeks. In the UK it’s sold as a food supplement, with no authorised health claims.

Facts here come from the makers’ own sites and the published trials, checked October 2026. Evopure isn’t connected with Ixoreal or any brand named here.

What is KSM-66?

KSM-66 is Ixoreal’s trademarked extract of ashwagandha (Withania somnifera). Its site describes it as:

• Root only, with no leaves; Ixoreal notes that most human trials used root.
• Full-spectrum. Ixoreal uses this to mean the extract keeps the plant’s compounds in roughly their natural balance, rather than concentrating one.
• Solvent-free. Made by a “green chemistry” process without alcohol or other chemical solvents.
• Low in withaferin A, a compound Ixoreal says the leaves are rich in.

The 5% figure comes from the trial papers: the 2012 stress trial describes KSM-66 as standardised to at least 5% withanolides, measured by HPLC. Withanolides are the compounds researchers usually measure in ashwagandha.

KSM-66 vs normal ashwagandha

Same plant, different processing. Plain root powder is ground, dried root and isn’t standardised, so trials used far more of it (around 5g a day). Unbranded root extracts vary: UK labels we checked this month gave 1.5% to 7% withanolides. A branded name like KSM-66 tells you which extract is inside, so you can compare a product with the trials that used it.

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KSM-66 dose and what the trials found

The best-known KSM-66 trials all used 300mg capsules:

• Stress (2012): 64 adults with chronic stress took 300mg twice a day for 60 days.
• Dose comparison (2019): 60 stressed adults took 125mg or 300mg twice a day, or a placebo, for 8 weeks.
• Sleep (2019): 60 adults with insomnia took 300mg twice a day for 10 weeks.

In all three, stress or sleep scores improved more than on placebo. The trials were small and run in India, and in each one Ixoreal supplied the KSM-66; the authors declared no competing interests. A 2022 review of 12 ashwagandha trials (1,002 people, several extracts) found it may help a little with how stressed people feel, clustering at 300 to 600mg a day, but rated the certainty of the evidence as low. No food supplement can claim to treat anxiety or insomnia.

300mg or 600mg? The UK KSM-66 capsules we checked were 300mg (once or twice a day) or 600mg (once a day), matching the trial amounts. Follow your product’s label and don’t combine products. Our guide to how much ashwagandha per day compares doses by extract, and when to take ashwagandha covers morning versus night. For the research by topic, see ashwagandha for anxiety, for sleep, for men and for women.

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Where Evopure fits

We sell online, direct from our own website:

• Flow CBD Oil: broad spectrum CBD with ashwagandha extract and maca root extract in MCT oil, plus our Energise terpene blend, in 500mg and 1,000mg 10ml bottles. The herbs are extracted in-house. Its page doesn’t name KSM-66 or give an amount of ashwagandha per dose, so it can’t be matched to the trials above. More in CBD and ashwagandha.
• Magnesium Glycinate Sleep Complex: a berry drink powder with magnesium bisglycinate and citrate (148mg of magnesium per serving), glycine, L-theanine, chamomile, passionflower, hops and oat straw. Magnesium contributes to a reduction of tiredness and fatigue. See ashwagandha vs magnesium.
• Reishi Mushroom Adaptogenic Complex: a reishi hot chocolate with reishi mushroom extract, organic cacao, maca, coconut milk powder and coconut sugar. It contains a little natural caffeine.

The FSA’s 10mg a day figure is precautionary advice rather than a legal limit, set while longer-term safety research continues. At Evopure we think it is a very cautious figure, and many adults use more. If you go above it, increase slowly, and check with your GP or pharmacist first if you take any medication.

Our products are for adults (18+) only. We don’t recommend our products during pregnancy or breastfeeding. For choosing a CBD oil in general, see our UK CBD oil guide.

KSM-66 vs Sensoril vs Shoden

These are the three branded extracts people compare most:

Three points help with “which is better?”:

• The percentages aren’t like for like. KSM-66 is measured as withanolides and Shoden as withanolide glycosides, so a higher number doesn’t simply mean stronger. That’s why Shoden’s dose is lower: Arjuna suggests 60 to 120mg a day.
• Root or leaf. Shoden and Sensoril include leaf, which is less studied than root. Arjuna now also sells a root-only version, Shoden-R.
• Each has its own trials, mostly small and supported by the maker. The Shoden stress trial and a Sensoril strength trial were both funded by their makers. No trial has compared the extracts head to head, so nobody can say one works better.

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Best KSM-66 in the UK: how to check a label

We don’t rank brands, but these checks work anywhere, from Home Bargains to online:

• KSM-66 named in the ingredients, not just on the front. If a label says “root extract” with no brand, it isn’t necessarily KSM-66: Vitabiotics’ tablet names none.
• mg of KSM-66 per daily dose. Holland and Barrett’s own-brand capsule gives 600mg once a day; Wild Nutrition gives 600mg in two capsules.
• Gummies and drinks often carry less. Wild Nutrition’s gummies give 100mg each, and mushroom drinks such as Spacegoods and Rheal’s Magic Matcha list 300mg per serving, often alongside caffeine.
• Other ingredients: added vitamins, magnesium, herbs or sweeteners.
• Testing and warnings: ask for lab results; read the pregnancy, liver and medication warnings.

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Is KSM-66 safe? The UK position

KSM-66 is legal as a food supplement in the UK in October 2026, but ashwagandha’s safety is under review:

• FSA: published a summary of its call for evidence in June 2026; a risk assessment will follow.
• Committee on Toxicity: discussed a third draft statement on ashwagandha in September 2026, still confidential.
• Meanwhile, the FSA has said it would advise people with pre-existing liver conditions and pregnant women to avoid ashwagandha supplements.
• Denmark banned ashwagandha in food supplements in 2023.

The US NCCIH notes drowsiness and stomach upset as side effects, rare liver injury, possible interactions with diabetes, blood pressure, thyroid, sedative, anti-seizure and immune-suppressing medicines, and that long-term safety is unknown. Avoid it in pregnancy or breastfeeding, if you’re under 18 or have a liver condition, and check with your GP or pharmacist first if you have a thyroid or autoimmune condition or take any regular medicine. Stop and see a doctor if your skin or eyes turn yellow. More in ashwagandha side effects and our UK safety review.

For the research on ashwagandha in general, see what does ashwagandha do?.

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FAQs

Sources

• Ixoreal. What is KSM-66? and Why choose KSM-66, checked 26 October 2026.
• Arjuna Natural. Shoden ashwagandha, checked 26 October 2026.
• Chandrasekhar K et al (2012). High-concentration full-spectrum ashwagandha root extract in reducing stress and anxiety in adults. PMID 23439798.
• Salve J et al (2019). Adaptogenic and anxiolytic effects of ashwagandha root extract in healthy adults. PMID 32021735.
• Langade D et al (2019). Ashwagandha root extract in insomnia and anxiety. PMID 31728244.
• Lopresti AL et al (2019). Stress-relieving and pharmacological actions of an ashwagandha extract (Shoden). PMID 31517876.
• Ziegenfuss TN et al (2018). An aqueous extract of Withania somnifera on strength training: the STAR trial (Sensoril). PMID 30463324.
• Akhgarjand C et al (2022). Ashwagandha for anxiety and stress: a systematic review and meta-analysis. PMID 36017529.
• Food Standards Agency, GOV.UK. Summary of responses to call for evidence on ashwagandha (June 2026).
• Committee on Toxicity, GOV.UK. Draft minutes of the 8 September 2026 meeting.
• Which? Ashwagandha: stress buster or health risk? (June 2026, FSA statement).
• NutritionInsight. International authorities’ response to ashwagandha safety concerns (2024).
• NCCIH. Ashwagandha: usefulness and safety.

General information, not medical advice. Evopure makes Flow CBD Oil, the Magnesium Glycinate Sleep Complex and the Reishi Mushroom Adaptogenic Complex, and isn’t connected with Ixoreal, Arjuna, Natreon or any brand named here. If something here is out of date, email support@evopure.co.uk and we will correct it.