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Best Supplements for Anxiety (2026)

Last reviewed: 2025-03-01 | Based on 10 products scored | Clinical dose: 300-600mg daily of a standardized root extract (KSM-66 or Sensoril)

Several supplements have clinical trial evidence for reducing anxiety, but the strength of that evidence varies dramatically. Ashwagandha (specifically KSM-66 extract) has the most consistent RCT data, with multiple studies showing significant reductions in perceived stress and anxiety scores versus placebo. Magnesium, L-theanine, and certain probiotics also show promise. We scored the top anxiety-related supplements by the rigor of their clinical evidence, because this is a category where placebo effects are strong and marketing claims outpace the science.

Our Top Picks

A
Best Overall

KSM-66 Ashwagandha Extract 300mg

$0.25/day at effective dose

B+
Best Value

Ashwagandha 450mg Standardized Extract

$0.14/day at effective dose

A
Best Quality-Verified

KSM-66 Ashwagandha 600mg

$0.42/day at effective dose

Detailed Reviews

#1Best Overall

KSM-66 Ashwagandha Extract 300mg

KSM-66 Root Extract (5% withanolides) | 300mg/serving | 180 servings

A
Evidence
A
Quality
A-
Value
A
Transparency
A
Price: $22.99
Cost/day: $0.25
Third-party tested: Yes
Proprietary blend: No

Nootropics Depot is known in the supplement community for rigorous quality testing and genuine ingredient sourcing

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#2Best Quality-Verified

KSM-66 Ashwagandha 600mg

KSM-66 Root Extract (5% withanolides) | 600mg/serving | 90 servings

A
Evidence
A
Quality
A-
Value
B
Transparency
A
Price: $37.99
Cost/day: $0.42
Third-party tested: Yes
Proprietary blend: No

600mg per capsule means you only need 1 capsule for a full clinical dose

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#3

KSM-66 Ashwagandha 300mg

KSM-66 Root Extract (5% withanolides) | 300mg/serving | 120 servings

A-
Evidence
A
Quality
B
Value
A
Transparency
A
Price: $17.99
Cost/day: $0.30
Third-party tested: No
Proprietary blend: No

Well-established supplement brand with a straightforward KSM-66 product at a competitive price

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Also Scored

#4
A-

Optimized Ashwagandha (Sensoril)

$0.35/day | Sensoril Root + Leaf Extract (10% withanolides)

#5
B+

Ashwagandha 450mg Standardized Extract

$0.14/day | Root Extract (2.5% withanolides)

#6
B+

Ashwagandha 500mg

$0.52/day | Root Extract (2.5% withanolides)

#7
B

Organic Ashwagandha 670mg

$0.28/day | Organic Root Extract + Supercritical CO2 Root Extract

#8
B

mykind Organics Ashwagandha

$0.50/day | KSM-66 Root Extract + Organic Ginger + Organic Probiotics

#9
B

Ashwagandha Root Liquid Phyto-Caps

$0.67/day | Root Extract (liquid phyto-cap)

#10
B-

Ashwagandha 1000mg

$0.23/day | Root Extract (standardization not specified)

What to Look For When Buying

  • Ashwagandha as KSM-66 at 300-600mg daily has the most consistent anxiety-reduction evidence in clinical trials
  • L-theanine at 200-400mg promotes calm without drowsiness - good for daytime anxiety and can be combined with ashwagandha
  • Magnesium glycinate at 200-400mg addresses a deficiency that can itself worsen anxiety symptoms
  • Avoid products marketed as 'natural anxiety cures' - no supplement replaces professional mental health treatment for clinical anxiety disorders
  • Start one supplement at a time so you can assess what actually helps you specifically
  • Kava has evidence for anxiety but carries liver toxicity concerns with long-term use - use with caution and medical guidance

Frequently Asked Questions

What is the difference between KSM-66 and Sensoril?

Both are clinically studied standardized ashwagandha extracts, but they differ in composition. KSM-66 is a full-spectrum root extract standardized to 5% withanolides. Sensoril uses both root and leaf, standardized to 10% withanolides, so it requires a lower dose (125-250mg vs 300-600mg). Both have clinical evidence for stress reduction. KSM-66 has more published trials overall (24+).

When should I take ashwagandha - morning or night?

There is no definitive evidence that timing matters significantly. For stress and anxiety, many people take it in the morning. For sleep benefits, taking it in the evening may be preferable. Some studies used twice-daily dosing (300mg morning and evening). Consistency matters more than timing.

How long does ashwagandha take to work?

Most clinical trials showing significant effects ran for 8-12 weeks. Some participants notice reduced stress within 2-4 weeks, but the full benefit typically develops over 6-12 weeks of consistent daily use. Do not expect immediate effects.

Can ashwagandha cause liver damage?

There have been rare case reports of liver injury associated with ashwagandha, which led to regulatory attention in some countries. However, controlled clinical trials have not found liver toxicity at standard doses. If you have pre-existing liver conditions, consult your doctor before use and monitor liver enzymes.

Is ashwagandha safe to take with medications?

Ashwagandha may interact with thyroid medications (it can increase thyroid hormone levels), immunosuppressants, sedatives, and blood sugar-lowering drugs. It should be discontinued 2 weeks before surgery. Always consult your doctor if you take any medications.

FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. The products discussed on this page are not intended to diagnose, treat, cure, or prevent any disease. Always consult with a qualified healthcare professional before starting any supplement regimen.