Ashwagandha KSM-66 – What the Herb Is and How It Is Used
Ashwagandha (Withania somnifera) is an adaptogenic herb with a long tradition in Ayurveda, and KSM-66 is one of the most studied standardised root extracts on the market. A common dose of a standardised extract is around 300–600 mg per day. Ashwagandha has no EU-approved health claims, so below we describe the herb's tradition, what standardisation means and how it is used – not promised health effects.
This guide is an overview. If you want to read about specific angles, we have separate articles on ashwagandha and cortisol/testosterone and on ashwagandha combined with Tongkat Ali.
What is ashwagandha?
Ashwagandha is a small shrub whose root has been used for over 3,000 years in the Ayurvedic tradition. In English it is sometimes called "winter cherry" or "Indian ginseng", although it is not related to true ginseng. The name means roughly "the smell of a horse" in Sanskrit, a reference to the root's characteristic odour.
The herb is counted among the adaptogens – a group of plants described in traditional herbal medicine as supportive of the body's ability to cope with strain. "Adaptogen" is a traditional and functional term, not an approved medical claim.
What does ashwagandha do – short answer
Ashwagandha is thus a traditional Ayurvedic herb that today is sold as a supplement, usually as a standardised root extract in capsule form. In Ayurveda it has been used as a generally strengthening herb, and modern research has taken an interest in how the herb and its withanolides work in the body. Since no health claims are approved in the EU, we can describe this tradition and this research interest – but not promise any effect.
Withanolides – the herb's signature compounds
The compounds that ashwagandha is most often measured and standardised on are called withanolides. They are a group of naturally occurring plant compounds (steroidal lactones) found in both root and leaf. When packaging states, for example, "5% withanolides", it is the level of these compounds that is meant – a measure of the extract's concentration, not a promise of effect.
Different parts of the plant and extraction methods give different withanolide profiles. Root extract and leaf extract differ, and a standardised extract has a more even level than an unmilled root powder where the amount can vary between batches.
What does KSM-66 mean?
KSM-66 is a trademarked ashwagandha extract obtained solely from the root and standardised to a high level of withanolides (at least 5%) – the active compounds the herb is measured on. That an extract is standardised means that each capsule contains an even, defined amount of these compounds, unlike an unmilled root powder where the level can vary. KSM-66 is produced with a water-based extraction method and is one of the most studied ashwagandha extracts on the market.
| Property | KSM-66 | Ordinary root powder |
|---|---|---|
| Part of the plant | Root only | Root (sometimes leaf) |
| Withanolides | Standardised, ≥5% | Varies |
| Documentation | Well studied | Less consistent |
This is why many people choose a standardised extract such as KSM-66 over loose powder – you know what you are getting. See Ashwagandha KSM-66 from Swanson or Ashwagandha from Noop.
KSM-66 vs Sensoril – what separates the extracts?
KSM-66 and Sensoril are the two best-known trademarked ashwagandha extracts, and they are produced in different ways. The differences concern which part of the plant is used and how high the withanolide level is standardised – not promised effects.
| Property | KSM-66 | Sensoril |
|---|---|---|
| Plant part | Root only | Root and leaf |
| Withanolides (standard) | ≥5% | ≥10% |
| Typical dose in studies | Often 300–600 mg | Often lower, e.g. 125–250 mg |
| Taste profile | Milder | More bitter (higher concentration) |
A third extract that is sometimes mentioned is Shoden, which is standardised to an even higher withanolide level. Which extract suits best is individual and depends among other things on the desired dose and form. Always check which extract and which withanolide level are stated on the packaging.
Extract or powder – and which forms are there?
Ashwagandha is sold in several forms, and the most important difference is between a standardised extract and an unmilled root powder:
- Standardised extract (capsule/tablet): concentrated and standardised to a set withanolide level, which gives an even amount per dose. KSM-66 and Sensoril are examples.
- Root powder: the whole, milled root. Traditionally used in Ayurveda, often mixed into a drink, but the withanolide level is lower and can vary.
- Other forms: also available as gummies or powder for a drink. Always read the contents, since such products can contain added sugar or a lower level of active extract.
Traditional use and what the research is looking at
In Ayurveda, ashwagandha has traditionally been used as a strengthening herb (a so-called "rasayana"). Modern research has taken an interest in the herb's role linked to stress management and recovery, but since no health claims are approved in the EU we report this as research interest and tradition – not as proven effects. If you want to read more about the specific cortisol/testosterone angle, we have our in-depth article.
Dosage and use
- Common dose: 300–600 mg standardised extract per day.
- Timing: can be taken with food; some prefer the evening, others split the dose.
- Continuity: adaptogens are traditionally used over time rather than on single occasions.
Always follow the dosage on your packaging.
Morning or evening?
The timing is flexible and there is no officially established "best" time. Some take their dose in the morning with breakfast, others in the evening, and some split the dose over two occasions. Since the extract is often taken with food, it can suit to link it to a meal so that it becomes a routine. Go by the packaging's recommendation and what works for you.
Side effects and tolerance
Ashwagandha is generally described as well tolerated at normal doses, but as with other supplements, side effects can occur. Reported and usually mild problems include gastrointestinal discomfort (for example nausea or loose stools), drowsiness and headache. Occasional individuals may react with hypersensitivity.
Such problems are usually dose-dependent and transient. A common approach is to start with a lower dose to see how the body reacts before possibly increasing. If you get problems that do not go away, you should stop and, if needed, contact a healthcare provider.
Who should be careful?
Ashwagandha is not advised during pregnancy and breastfeeding. If you have a thyroid disease, an autoimmune disease or take medicines, you should consult a doctor first, since the herb can affect certain conditions and medications. The same applies if you are going to have surgery or take sedative medicines. Start with a lower dose to see how you react.
Frequently asked questions (FAQ)
Ashwagandha has no EU-approved health claims, so we cannot promise any effect. It is an adaptogenic herb with a long tradition in Ayurveda, and research is investigating, among other things, its role in stress management.
What does ashwagandha do in the body?We cannot claim any definite effect, since no health claims are approved in the EU. The herb contains withanolides and has in Ayurveda traditionally been used as a strengthening herb. Modern research is investigating how the herb and its compounds work.
What are withanolides?Withanolides are the natural plant compounds (steroidal lactones) that ashwagandha is standardised and measured on. A stated percentage, such as "5% withanolides", describes the extract's concentration.
What does KSM-66 mean?KSM-66 is a standardised ashwagandha extract obtained solely from the root, with a high and even level of withanolides (at least 5%). The standardisation means that each capsule contains a defined amount of active compounds.
What is the difference between KSM-66 and Sensoril?KSM-66 is obtained solely from the root and standardised to at least 5% withanolides. Sensoril is obtained from root and leaf and standardised to a higher level (at least 10%), which often means a lower dose. The differences concern production and concentration, not promised effects.
How much ashwagandha should you take?A common dose of a standardised extract is 300–600 mg per day. Follow the dosage on the packaging and preferably start low.
When should you take ashwagandha – morning or evening?It can be taken with food, and the timing is flexible – some choose the morning, others the evening, and some split the dose. Adaptogens are traditionally used regularly over time.
Does ashwagandha have any side effects?The herb is generally described as well tolerated, but reported, usually mild side effects can include gastrointestinal discomfort, drowsiness and headache. Start low and stop if problems do not go away.
Who should avoid ashwagandha?Pregnant and breastfeeding women are advised against it. Anyone who has a thyroid or autoimmune disease or takes medicines should consult a doctor first.
Summary
Ashwagandha is a classic adaptogenic herb, and KSM-66 is a well-standardised root extract with an even withanolide level. Sensoril differs by being obtained from root and leaf with a higher withanolide level. A common dose is 300–600 mg per day, the timing is flexible and the herb is generally described as well tolerated – preferably start low. Explore ashwagandha from Noop or read on about ashwagandha and Tongkat Ali.
Ashwagandha has no EU-approved health claims. The content is general information, not medical advice. Consult a doctor in case of illness, medication, pregnancy or breastfeeding.
