For stress relief and cortisol management, this delivers 600mg of **KSM-66 Ashwagandha** per capsule — hitting the top of the 300–600mg clinical range used in research. KSM-66 is the most studied branded ashwagandha extract, standardized to a minimum 5% withanolides, and multiple RCTs show it can reduce your perceived stress and lower cortisol levels within 8 weeks.

The formula includes 5mg of **BioPerine** (black pepper extract) to support absorption. The single-capsule serving keeps things simple, and the 60-capsule count gives you a full two-month supply at one per day.

One thing to keep in mind: ashwagandha may interact with thyroid medications and is not recommended during pregnancy. If you're taking it for sleep support, some studies used doses split between morning and evening, so a single 600mg dose may work differently than two 300mg doses spread throughout your day.

BioStacks
Nutricost

KSM-66, Ashwagandha Root Extract, 60 Capsules

1 Capsule · 60 servings · $0.25/serving

iHerbAmazon

Best for

Stress & Mood

Ingredients (2)

Organic KSM-66 Ashwagandha Extract

100%

Dose

600 mg

Target

300–600 mg

Form

Premium

BioPerine Black Pepper Extract

100%

Dose

5 mg

Target

5–20 mg

Form

—

Other Ingredients (4)

Magnesium StearateLubricant

A salt of stearic acid used as a lubricant in tablet and capsule production

Silicon DioxideAnti-caking

Fine silica powder used to prevent clumping

HypromelloseCapsule

Plant-derived capsule material from cellulose

StarchBinder

Carbohydrate polymer used as a binder, filler, and disintegrant in tablets and capsules

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Sources & Scoring

Nutrient data (RDA, UL, and safety thresholds) sourced from: NIH Office of Dietary Supplements and National Academies Dietary Reference Intakes (DRI).

This is not medical advice. Consult a healthcare provider before making changes to your supplement routine.

The score analyzes what's on the label: ingredient doses vs. clinical ranges, chemical forms, evidence levels, and known interactions. It does not verify label accuracy or test for contaminants — for that, look for third-party certifications like USP or NSF.

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