The short answer
Six of the seven ashwagandha supplements we compared use the same patented extract, KSM-66, organic, standardised to 5% withanolides. At the same dose of 600 mg a day, the one used in clinical trials, the price ranges from 121 EUR a year at Dynveo to 176 EUR at Nat&Form: a 46% gap for an identical ingredient. But the most important point is not the price: Anses, the French food safety agency, advises several groups of people against this plant, and the evidence for its effectiveness remains of low certainty.
The ranking, at the same dose
| Brand and size | Extract | Price | Price for 600 mg | One year at 600 mg a day |
|---|---|---|---|---|
| Dynveo, 60 capsules of 600 mg | Organic KSM-66, root | 19.90 EUR | 0.332 EUR | 121 EUR |
| Nutri&Co, 120 capsules, 600 mg for 2 | Organic KSM-66, root | 20.90 EUR | 0.348 EUR | 127 EUR |
| Dieti Natura, 60 capsules of 250 mg | Organic KSM-66, root | 9.95 EUR | 0.398 EUR | 145 EUR |
| Novoma, 60 capsules of 500 mg, 1,000 mg for 2 | Organic KSM-66, root | 21.90 EUR | 0.438 EUR | 160 EUR |
| Sensilab, 120 capsules, 600 mg for 2 | KSM-66, root, with piperine | 26.99 EUR | 0.450 EUR | 164 EUR |
| Nat&Form, 60 capsules, 600 mg for 2 | Organic KSM-66, root | 14.50 EUR | 0.483 EUR | 176 EUR |
| Nutrimuscle, 30 capsules | Shoden, leaf and root | 19.95 EUR | 0.665 EUR per capsule | 243 EUR |
What this table tells us
KSM-66 is everywhere, so price is the only thing to compare
Dynveo, Nutri&Co, Dieti Natura, Nat&Form, Novoma and Sensilab buy the same aqueous root extract, at the same standardisation. Between them, the difference is mainly the price and the size of the capsule; Sensilab adds piperine (black pepper), selenium and pantothenic acid, and the amount of piperine is not the same in the table on its page and in its ingredient list. Dynveo is the cheapest and puts 600 mg in a single capsule; Nutri&Co, Nat&Form, Novoma and Sensilab need two, Dieti Natura two and a half.
Watch the dose on the label
Dieti Natura recommends four capsules a day, i.e. 1,000 mg of extract. The bottle of 60 capsules then lasts fifteen days and works out at 0.66 EUR a day. Brought back to the 600 mg used in studies, it becomes competitive again. Always read the dose of extract per day, not the number of capsules.
Novoma: KSM-66 at 1,000 mg a day
Novoma uses the same organic KSM-66, standardised to 5% withanolides, but recommends two 500 mg capsules, i.e. 1,000 mg of extract and 50 mg of withanolides a day. At that dose, a bottle of 60 capsules lasts a month and works out at 0.73 EUR a day (recorded on 27/10/2026). Brought back to the 600 mg used in studies, the cost falls to 0.438 EUR, or 160 EUR a year, between Dieti Natura and Nat&Form; in a pack of three bottles, 0.394 EUR. The page offers a certificate of analysis to download.
Nutrimuscle makes a different choice, and it matters
Nutrimuscle uses the Shoden extract, standardised to 35% withanolide glycosides, taken from the leaf and the root. Its page states 215 mg of ashwagandha per capsule, of which 6 mg of withanolide glycosides. Two remarks. First, the largest number of trials concern KSM-66 at 600 mg; results do not carry over from one extract to another. Second, Anses points out that the leaves of the plant are rich in alkaloids and notes cases of « root » supplements adulterated with leaves. An extract that openly uses the leaf is not adulterated, but it is not comparable.
What the studies say
The founding KSM-66 trial, published in 2012, involved 64 stressed adults for 60 days at 600 mg a day, with a reduction in perceived stress and blood cortisol compared with placebo. A 2022 meta-analysis pooling 12 trials and 1,002 participants confirms an effect on stress and anxiety, greatest between 300 and 600 mg a day for stress. But its authors consider the certainty of the evidence low: short trials, small samples, and very heterogeneous results from one study to another.
Our guide on diet and stress management reviews the best-established levers, and the one on foods for sleep completes the topic.
What Anses says
In its opinion of 19 April 2024, Anses concludes that it is impossible to define a safe level of intake, for lack of sufficient data, and joins the findings of Germany, Denmark and the Netherlands. Denmark and Germany recommend not using the plant in food supplements. In France it remains authorised, but Anses advises against its use:
- in pregnant or breastfeeding women;
- in under-18s;
- in people with endocrine disorders, in particular of the thyroid;
- in people with liver or heart disorders;
- in people on treatment that depresses the central nervous system.
It also advises against it when driving or using machinery, because of its sedative effects. The most commonly reported adverse effects in France are digestive, drowsiness and skin reactions.
Our view
If you do not fall into any of the groups above and want to try it, choose a root KSM-66 at 600 mg a day, for a limited period, and stop at the first unusual sign. On price, Dynveo and Nutri&Co are ahead. If you take any medication, talk to your doctor or pharmacist first.
Our sources
- Official Dynveo, Nutri&Co, Dieti Natura, Nat&Form and Nutrimuscle pages, accessed on 24/09/2026, and Novoma, accessed on 27/10/2026.
- Official Sensilab page, accessed on 27/10/2026: composition, dosage, format and price.
- Anses, opinion of 19 April 2024 on the risks linked to the use of Withania somnifera preparations in food supplements, referral no. 2021-SA-0077.
- Chandrasekhar K. et al., Indian Journal of Psychological Medicine, 2012 (PMID 23439798).
- Akhgarjand C. et al., Phytotherapy Research, 2022, meta-analysis of 12 randomised trials (PMID 36017529).