KSM-66 vs Shoden — which ashwagandha extract is better?

Both are legitimate, well-studied root extracts; they just concentrate differently. KSM-66 is root-only, standardized to about 5% withanolides, and is the most researched extract (used in most stress and testosterone trials) at 300-600mg/day. Shoden is a higher-potency extract standardized to roughly 35% withanolides, so it works at much smaller doses (around 120-240mg) and features in several sleep studies. Neither is clearly superior — choose by which has evidence for your goal and dose accordingly.

How much ashwagandha should I take per day?

Most positive trials used 300-600mg per day of a standardized root extract (like KSM-66), typically split into two doses or taken once daily, for at least 8 weeks. Higher-potency extracts like Shoden are dosed lower (about 120-240mg) because they contain more withanolides per milligram. More is not better — stay within the studied range.

Is ashwagandha safe? Are there risks?

For most healthy adults short-term use is well tolerated, but there are real cautions. Rare cases of liver injury have been reported, so stop and see a doctor if you notice yellowing skin, dark urine, or unusual fatigue. Do not take ashwagandha if you are pregnant (it may cause miscarriage). Use caution if you have a thyroid condition (it can raise thyroid hormone levels), an autoimmune disease, or take sedatives or immunosuppressants. Long-term safety beyond a few months is not well established.

Best Ashwagandha Supplement (2026): KSM-66 vs Shoden, Ranked by Dose & Cost

Q: What is the best ashwagandha supplement?

For most people the best ashwagandha is a KSM-66 root extract at 300-600mg per day — it is the most clinically studied extract, standardized to root only with at least 5% withanolides. Best value is Nootropics Depot KSM-66 (~$0.22/day, third-party tested). For a clinically-tested high-potency option, Thorne Ashwagandha uses Shoden extract and carries NSF Certified for Sport. Match the dose to the studies: 300-600mg/day of a standardized extract.

By Verified Supplement Data · Updated May 30, 2026 · Methodology · About Us

Buy a standardized root extract at the studied dose. The two that matter are KSM-66 (root-only, ~5% withanolides, the most-researched, dosed 300-600mg/day) and Shoden (higher-potency ~35%, dosed lower). Skip cheap "generic root" with no standardization.

Best value: Nootropics Depot KSM-66 — 300mg, third-party tested, ~$0.22/day. Budget KSM-66: Jarrow KSM-66. Cleanest label: Thorne (Shoden), NSF Certified for Sport.

What it's actually good for: stress and anxiety (best evidence), sleep (good), and modest testosterone/strength support in men. For stress · for sleep.

The only thing that matters: extract and dose

Ashwagandha is one of the rare herbal supplements with genuinely decent clinical evidence — but only at the doses and extracts that were actually studied. The single biggest mistake is buying "ashwagandha root powder, 1000mg" with no standardization and assuming it matches the research. It doesn't. What was tested were standardized extracts, and two dominate the literature.

The two extracts worth buying
	KSM-66	Shoden
Source	Root only	Root + leaf, high-concentration
Standardization	~5% withanolides	~35% withanolides
Studied dose	300-600mg/day	~120-240mg/day
Strongest evidence	Stress, cortisol, testosterone	Sleep
Research volume	Most-studied extract	Newer, growing

Withanolides are the active compounds, which is why a 120mg Shoden capsule can match a 600mg KSM-66 dose — it's more concentrated. Don't compare ashwagandha products by milligrams alone; compare by extract and the dose used in the trials for your goal.

What the evidence supports

Stress & anxiety (strongest): A randomized, placebo-controlled trial of KSM-66 found significant reductions in perceived stress and morning cortisol (Lopresti 2019, PMID: 31517876), and a 2022 meta-analysis of RCTs concluded ashwagandha meaningfully reduced anxiety and stress measures (Akhgarjand 2022, PMID: 36017529).
Sleep (good): A systematic review and meta-analysis found ashwagandha improved sleep, with larger effects at 600mg/day and 8+ weeks (Cheah 2021, PMID: 34559859).
Strength & testosterone in men (modest): Combined with resistance training, ashwagandha increased muscle strength and testosterone versus placebo in one RCT (Wankhede 2015, PMID: 26609282).

Best ashwagandha, ranked

Ashwagandha supplements ranked by cost per day
Product	Extract	Dose	Servings	Price	Cost/Day	Certification	Buy
NOW Foods Ashwagandha Extract (450mg, 90ct)	Generic root (~2.5%)	450mg	90	$9.88	$0.11	None	Buy
Nootropics Depot KSM-66 Ashwagandha (300mg, 90ct) Best Value	KSM-66 (5% withanolides)	300mg	90	$22.99	$0.25	Third-Party Tested	Buy
Jarrow Formulas Ashwagandha KSM-66 (300mg, 120ct) Budget Pick	KSM-66 (5% withanolides)	300mg	60	$17.99	$0.30	None	Buy
Thorne Ashwagandha (Shoden, 120mg, 30ct) Quality Pick	Shoden (~35% withanolides)	120mg	30	$22.00	$0.73	NSF Certified for Sport	Buy

Which to pick

Best value: Nootropics Depot KSM-66

Nootropics Depot KSM-66 gives you the most-researched extract at a studied 300mg dose, third-party tested, for about $0.22/day. For the majority of people taking ashwagandha for stress, this is the pick.

Cleanest label: Thorne (Shoden)

Thorne Ashwagandha uses high-potency Shoden and carries NSF Certified for Sport — third-party tested for banned substances and label accuracy. Costs more per day, but it's the choice if you compete in a tested sport or want maximum certainty, and Shoden has the better sleep evidence.

Budget KSM-66: Jarrow

Jarrow KSM-66 is the same studied extract at the lowest KSM-66 price here. A reasonable entry point.

Safety: the part most "best ashwagandha" lists leave out

Ashwagandha is well tolerated by most people short-term, but it is not risk-free, and honest guidance matters here:

Liver injury (rare but real): Documented cases of ashwagandha-associated liver injury exist. Stop and see a doctor if you develop yellowing of the skin/eyes, dark urine, nausea, or unusual fatigue.
Pregnancy: Do not use — it may cause miscarriage.
Thyroid: It can raise thyroid hormone levels. If you have a thyroid condition or take thyroid medication, talk to your doctor.
Autoimmune disease: It may stimulate immune activity; caution with autoimmune conditions and immunosuppressant drugs.
Sedatives: Effects can be additive with sedatives and alcohol.
Duration: Most studies ran 8-12 weeks. Long-term safety beyond a few months isn't well established; periodic breaks are reasonable.

Safety summary drawn from the NIH Office of Dietary Supplements fact sheet.

Frequently asked questions

What is the best ashwagandha supplement?

A KSM-66 root extract at 300-600mg/day for most people — most studied, standardized. Best value: Nootropics Depot KSM-66 (~$0.22/day). For a tested high-potency option: Thorne (Shoden), NSF Certified for Sport.

KSM-66 vs Shoden — which is better?

Both are legitimate. KSM-66 is root-only (~5% withanolides, 300-600mg, most-researched, best stress/testosterone data). Shoden is higher-potency (~35%, ~120-240mg, more sleep data). Pick by your goal and dose accordingly.

How much should I take?

300-600mg/day of a standardized extract like KSM-66 for at least 8 weeks. Higher-potency Shoden is dosed lower (~120-240mg). More isn't better.

Is it safe?

Usually well tolerated short-term, but rare liver-injury cases exist; avoid in pregnancy; use caution with thyroid conditions, autoimmune disease, sedatives, and immunosuppressants. Long-term safety isn't well established.

Related guides

Sources

Lopresti AL, et al. "An investigation into the stress-relieving and pharmacological actions of an ashwagandha (Withania somnifera) extract." Medicine (Baltimore). 2019;98(37):e17186. PMID: 31517876
Akhgarjand C, et al. "Does Ashwagandha supplementation have a beneficial effect on the management of anxiety and stress? A systematic review and meta-analysis of RCTs." Phytother Res. 2022;36(11):4115-4124. PMID: 36017529
Cheah KL, et al. "Effect of Ashwagandha (Withania somnifera) extract on sleep: A systematic review and meta-analysis." PLoS One. 2021;16(9):e0257843. PMID: 34559859
Wankhede S, et al. "Examining the effect of Withania somnifera supplementation on muscle strength and recovery: a randomized controlled trial." J Int Soc Sports Nutr. 2015;12:43. PMID: 26609282
NIH Office of Dietary Supplements. "Ashwagandha: Is it helpful for stress, anxiety, or sleep?" ods.od.nih.gov