Ashwagandha KSM-66, Sensoril or powder: what is the difference?

KSM-66 is an extract of the root only, standardised to at least 5 percent withanolides. Sensoril uses root and leaf and is standardised to around 10 percent. Ground root powder is not an extract at all and holds far less active compound per gram.

So you cannot carry doses across. 300 mg of one product is a very different thing from 300 mg of another.

What strikes me here is how rarely this gets explained. The ten results Google returns are almost all web shops, and they rarely compare their own form with the rest.

What is KSM-66 good for?

KSM-66 is the form that turns up most often in a sports context. It is a water-based root extract, standardised by its manufacturer to at least 5 percent withanolides, and usually dosed between 300 and 600 mg a day. That sits close to what the resistance training study used: 300 mg of root extract, twice daily (Wankhede, 2015).

There is a caveat here that you rarely see stated.

The abstract of that study names no brand. It says root extract, not KSM-66. A product page that ties the study to the brand is giving you an interpretation, not a quote.

What is the difference between ashwagandha and KSM-66?

Ashwagandha is the plant; KSM-66 is one patented extract of that plant. The difference lies in the plant part, the production process and the guaranteed percentage of active compound. A jar that only says ashwagandha tells you nothing about that percentage.

The bottom row is the trap. Say you buy a capsule holding 500 mg of powder. That sounds like a high dose and is not.

Powder is the whole root, fibre and starch included. Extract is concentrated, and that can easily mean a tenfold difference in active compound.

Which extract did the trials use?

Of the four most quoted trials, exactly one names a branded extract in its abstract. That is the crossover study in men aged 40 to 70, which used Shoden and delivered 21 mg of withanolide glycosides a day (Lopresti, 2019).

That figure of 21 mg sits on a completely different scale from the 600 mg a day in the other studies.

It is not a contradiction: one number is extract, the other is the active fraction inside it. Put the two side by side without explanation and you are comparing apples with pears.

The thyroid study used 600 mg of root extract a day (Sharma, 2018), with no brand named in the abstract.

What happens if you take ashwagandha daily?

In the trials it was taken every day, for eight to sixteen weeks, and that is where the measured effects come from. What happens after that has not been studied well. For long-term daily use over months or years, the data are missing.

That is neither reassurance nor a warning. It is a gap in the knowledge.

On 5 March 2024 RIVM advised against using supplements containing ashwagandha, after reports including harmful effects in the liver. What has been reported is covered in ashwagandha side effects.

Which form suits which goal?

The honest summary is that no head-to-head comparison exists between KSM-66 and Sensoril in the same participants. What you read online about one form being better for energy and the other for sleep comes from marketing, not from a comparative trial.

What is true is that the doses differ because the withanolide content differs.

If you want to know what it does in you, I would say what I say in ashwagandha reviews: a feeling is a weak yardstick. A cortisol test beforehand at least gives you a reference point.

What to look for on the label

Three things make a label readable. Does it say extract or powder, does it state a withanolide percentage, and does it name a branded extract such as KSM-66, Sensoril or Shoden.

If that percentage is missing, you do not know what you are taking.

The full picture of what this does to your blood values is in the ashwagandha overview. Other supplements judged the same way are in 9 supplements for athletes.

Every blood test result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.

References

• RIVM. Advice on products containing Huperzia serrata, Tabernanthe iboga or ashwagandha. 5 March 2024.
• Wankhede S, Langade D, Joshi K, Sinha SR, Bhattacharyya S. J Int Soc Sports Nutr. 2015 (PMID 26609282).
• Sharma AK, Basu I, Singh S. J Altern Complement Med. 2018 (PMID 28829155).
• Lopresti AL, Drummond PD, Smith SJ. Am J Mens Health. 2019 (PMID 30854916).