Ashwagandha · Withania somnifera (KSM-66)
The best-studied adaptogen for stress and sleep.
Short answer
Ashwagandha (Withania somnifera (KSM-66)) is a adaptogen with evidence grade B, meaning it is supported by human RCTs. We track 9 produkter containing Ashwagandha. Typical doses range from 120.0 to 600.0 mg per portion. The top-ranked product scores 8.2 out of 10 on our composite scale (dose, evidence, price, testing, transparency). Prices range up to $32.99 per månad.
Top Ashwagandha produkter
| Product | Varumärke | Dose | Pris/mo | 3rd-party tested | Poäng |
|---|---|---|---|---|---|
| KSM-66 Ashwagandha Supplement | 600.0 mg | $19.95 | Yes | 8.2 | |
| Full Spectrum Ashwagandha - 60 capsules | 600.0 mg | $32.99 | Yes | 8.0 | |
| Ashwagandha Extract Powder | 600.0 mg | $20.97 | No | 7.4 | |
| KSM-66 Capsules | Ashwagandha Root | 300.0 mg | $19.99 | Yes | 7.1 | |
| Jarrow Formulas Ashwagandha (KSM-66), 300 mg | 300.0 mg | $28.92 | No | 6.5 |
Scores are editorial judgments, not a scientific standard. Se how we score.
What it is
A root used in Ayurvedic medicine for thousands of years. Modern trials show it blunts stress hormones (cortisol) and improves sleep quality.
Why people take it
600 mg/day of a standardised extract reduces perceived stress and lowers cortisol ~20% in a couple of months. Also shows benefits in sleep, testosterone (in men), and gym performance.
Our verdict
One of the few 'traditional' herbs with solid modern trial data. Choose KSM-66 or Sensoril, branded extracts with standardised withanolides.
Structure & class
Withania somnifera root extract. Contains withanolides (KSM-66 standardised to 5%).
Mechanism & clinical data
Chandrasekhar 2012 showed 300 mg BID reduced Perceived Stress Scale scores 44% over 60 days. Meta-analyses confirm anxiolytic effect and cortisol lowering.
Pharmacokinetics
Multi-day biological effect.
Dose & forms
What to watch out for
Not for pregnancy, hyperthyroidism, or with sedatives. Effects on TSH can complicate thyroid conditions.
Säkerhet limits and interactions
When a product exceeds the UL or contains an ingredient with clinically significant interactions, a "Review advised" flag appears on its product page and links here.
Where this dose comes from
The trial dose above is our editorial pick from the published human trials for this ingredient. We choose the dose that the best-available studies used on the endpoint most relevant to longevity. The range shows the lowest and highest doses tested in published trials. The landmark studies below are the papers we read to set it. You can click through and check our work.
When new trials publish, our automated sweeps flag them. If a new study materially changes the dose, we update it through editorial review and record the old dose, new dose, and the triggering study in every affected product's recommendation history. The dose is never changed automatically.
Regelverk status
Timeline
Regelverk events, evidence grade changes, and key research milestones for Ashwagandha, most recent first. Every entry links to its primär source.
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EU Court sharpens the bar for botanical health claimsA Court of Justice of the European Union ruling in april 2025 further tightened the requirements for how botanical ingredients (herbs, plant extracts) can be marketed with health claims in the EU, effectively removing much of the flexibility of the on-hold list.
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EU heads of food safety agencies prioritize ashwagandha for restrictionThe HoA Working Group on Food Supplements (26 European countries, chaired by BVL Germany and NVWA Netherlands) published its first report identifying 117 supplement substances as potential health risks. Ashwagandha (Withania somnifera) was among 12 substances prioritized for Article 8 restriction under Regulation (EC) No 1925/2006. The BfR separately recommended ashwagandha root be placed in Annex III Part C (substances under Community scrutiny) based on liver toxicity case reports. Germany and the Netherlands formally submitted the 12 priority substances to the European Commission in september 2024 to initiate the procedure.
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EU report identifies 117 supplement substances as potential health risksThe HoA Working Group on Food Supplements (26 European countries) published its first report evaluating 117 substances used in food supplements. Of these, 65 were assessed as likely novel foods, 6 were already regulated, 34 had insufficient data, and 12 were prioritized for Article 8 restriction under Regulation (EC) No 1925/2006. The 12 priority substances include ashwagandha, curcumin, melatonin, piperine, St. John's wort, coumarin, p-synephrine, maca, holy basil, Melaleuca, black cohosh, and L-tryptophan. The report drew on 1,500 RASFF alerts reviewed between 2017 and mid-2022.
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Chandrasekhar et al. 2012600 mg KSM-66/day for 60 days significantly reduced stress and cortisol.
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EU Health Claims Regulation adoptedRegulation (EC) No 1924/2006 laid down harmonised rules for nutrition and health claims made on foods, including supplements. Only claims listed in the EU Register of authorised claims can be used. Rejected botanical claims are held in a separate on-hold list.
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EU introduces the Novel Food RegulationRegulation (EC) No 258/97 required any food or food ingredient without a history of consumption in the EU before 15 maj 1997 to be authorised before being placed on the market. This is the framework that captures NMN, spermidine as a supplement ingredient, urolithin A, and many other longevity actives.
Ashwagandha (KSM-66 extract) lowers serum cortisol and stress scores in chronically stressed adults, with rare but real liver injury case reports.
Verified 2026-06-16. We update this section as new peer-reviewed trials land.
Best-supported claim
Ashwagandha's best-supported claim is cortisol and stress reduction, using the specific KSM-66 root extract standardized to 5% withanolides. The foundational trial by Chandrasekhar, Kapoor, and Anishetty randomized 64 chronically stressed adults to 300 mg KSM-66 twice daily or placebo for 60 days, finding a 27.9% reduction in serum cortisol versus 7.9% in placebo (p=0.002), alongside a 44% reduction in Perceived Stress Scale scores (https://ksm66ashwagandhaa.com/wp-content/uploads/2018/02/65999KSM66AshwagandhaInfoNo1.pdf). Two independent 2025 meta-analyses reinforced this: one pooling 15 RCTs and 873 adults found significant cortisol reduction and anxiety scale improvement, and another pooling 7 RCTs and 488 participants found a pooled cortisol reduction of -1.16 micrograms/dL (95% CI -1.64 to -0.69, p<0.001). For male fertility, a pilot study of oligospermic men found 90 days of ashwagandha root extract increased sperm concentration by 167% and testosterone by 17% versus baseline, though this was not placebokontrollerad for the sperm outcome and needs replication with a control arm (https://pmc.ncbi.nlm.nih.gov/articles/PMC3863556/).
Not supported by the evidence base
Ashwagandha is marketed as a broad hormone optimizer for testosterone in all men, but the evidence is more selective than that framing suggests. A randomized, dubbelblind, placebokontrollerad crossover trial in healthy males aged 40-70 found ashwagandha increased DHEA-S and testosterone significantly versus placebo, but found no significant effect on cortisol, estradiol, fatigue, vigor, or sexual well-being, meaning the hormone changes did not translate into subjectively noticeable benefits in this healthy population (https://pmc.ncbi.nlm.nih.gov/articles/PMC6438434/). Marketers also frequently omit ashwagandha's documented, if rare, liver risk: a case series identified 6 to 10 documented cases of ashwagandha-induced liver injury with jaundice, at doses as low as 450 mg/day, occurring 2 to 12 weeks into supplementation, though all reported cases were reversible after stopping. Most controlled trials at 300-600 mg/day for 8-12 weeks found no significant change in liver enzymes, so the injury risk appears real but rare rather than a typical dose-response effect.
Typical dose
300 mg twice daily (600 mg/day total) of KSM-66 root extract standardized to at least 5% withanolides
Säkerhet
In the KSM-66-specific evidence base, safety studies including a 12-month trial in 191 participants found no clinically relevant changes in liver enzymes (AST, ALT) or thyroid hormones at 600 mg/day (https://pmc.ncbi.nlm.nih.gov/articles/PMC12986965/). Side-effect rates in KSM-66 trials were comparable between active treatment and placebo groups (around 4% in both). However, documented case reports exist of ashwagandha-induced liver injury, including a case series covering 6-10 cases with a cholestatic or mixed hepatocellular pattern, typically resolving within 1-9 months of stopping. Ashwagandha can raise thyroid hormones (T3, T4) and lower TSH in people with subclinical hypothyroidism, making it contraindicated in hyperthyroidism or Graves' disease. It is contraindicated in pregnancy.
Interactions worth flagging
- thyroid medications (levothyroxine)
- sedatives, benzodiazepines, and sleep medications (additive sedation via GABA activity)
- immunosuppressants
- diabetes medications (may lower blood sugar further)
Three recent studies to know
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Ashwagandha supplementation and cortisol, anxiety outcomes: a systematisk översikt and metaanalysLäs studie →
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The Clinical Implications of Ashwagandha (Withania somnifera) on Liver and Thyroid FunctionLäs studie →
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A Randomized, Double-Blind, Placebo-Controlled, Crossover Studie Examining the Hormonal and Vitality Effects of Ashwagandha in Aging, Overweight MalesLäs studie →
Landmark studies
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Chandrasekhar et al. 2012
600 mg KSM-66/day for 60 days significantly reduced stress and cortisol.
Läs studie →
Found in these produkter (9)
Alla produkter in our catalog that contain Ashwagandha, ranked by our overall score. Ranking is editorial, never paid.
Buying guides and comparisons
Related ingredients
Se alla in Adaptogen →Molekyler in the same class, plus the actives most often formulated alongside Ashwagandha in our catalogue.
Frequently asked questions
What is Ashwagandha?
A root used in Ayurvedic medicine for thousands of years. Modern trials show it blunts stress hormones (cortisol) and improves sleep quality.
What dose of Ashwagandha should I take?
The trial dose in published human studies is 600 mg per dag, with a range of 300 to 1200 mg per dag. Always consult a qualified clinician before starting any supplement.
Is Ashwagandha safe?
Not for pregnancy, hyperthyroidism, or with sedatives. Effects on TSH can complicate thyroid conditions.
What is the best Ashwagandha supplement?
We track 9 produkter containing Ashwagandha. The top-ranked product scores 8.2 out of 10 on our composite scale, which evaluates dose, evidence, price, third-party testing, and transparency. See the comparison table above. Scores are editorial judgments, not a scientific standard.
What is the evidence grade for Ashwagandha?
Ashwagandha has evidence grade B, meaning it is supported by human RCTs. Grade A means replicated human RCTs with hard endpoints. Grade B means human RCTs with biomarker outcomes. Grade C means mixed or small human trials. See our evidence grading methodology.
Data verification
Bevisning grades are reviewed when new human RCTs are published. Product counts update automatically as new produkter are added. Dose ranges reflect published trial data, not brand recommendations. Read how we verify.