Root extract (unstandardized or low-ratio) vs. Standardized root extract, >=5% withanolides (KSM-66-type)
Among 1,088 on-market ashwagandha (withania somnifera) products with an identifiable primary form, 93.6% use Root extract (unstandardized or low-ratio) (1,018 products) and 6.4% use Standardized root extract, >=5% withanolides (KSM-66-type) (70).
| Root extract (unstandardized or low-ratio) | Standardized root extract, >=5% withanolides (KSM-66-type) | |
|---|---|---|
| Quality tier | Tier 2 | Tier 1 |
| Ashwagandha (Withania somnifera) by weight | — | — |
| Share of market | 93.6% | 6.4% |
| On-market products | 1,018 | 70 |
| Median declared dose | 250 mg middle half: 125–470 | 100 mg middle half: 50–300 |
| Most common brands | Bluebonnet, Pure Encapsulations, Source Naturals | Herbadiet, Himalaya, MRM |
Doses are declared per serving in mg. “By weight” is the share of the ingredient that is the nutrient itself (e.g. elemental magnesium in a magnesium salt).
Why Root extract (unstandardized or low-ratio) is tier 2
Concentrated relative to raw powder but without a guaranteed withanolide %, so potency is less reproducible than standardized extracts used in RCTs.
Source: uncertain -- needs review
Why Standardized root extract, >=5% withanolides (KSM-66-type) is tier 1
This is the specific material used in the largest and most-cited RCT and multiple subsequent trials -- the strongest direct clinical evidence base of any commercial ashwagandha form.
Source: Chandrasekhar K et al. 2012, Indian J Psychol Med 34(3):255-262, PMID 23439798