http://www.ksm66ashw...d_you_know.html
"Make sure that you assess the concentration of Withaferin A. Not all withanolides are beneficial. Withaferin A is one withanolide which is cytotoxic, as has been established in multiple scientific studies. So, it is undesirable to have Withaferin A in an ashwagandha extract when the intended use is for classical applications like building anti-stress ability, energy, cognition and immunity. Some ashwagandha extracts have high levels of Withaferin A because the manufacturers use ashwagandha leaves. Using leaves spikes up the overall withanolide content, but it also brings in the undesirable withanolide ‘Withaferin A’. KSM-66 consists of negligible levels of Withaferin A, making it very safe for human consumption."
The reference above is to a scare tactic claim with no references from the manufacturer of "KSM ashwagandha". It is total hogwash.
Google Ashwagandha toxicity, or see Safety assessment of Withania somnifera extract standardized for Withaferin A: Acute and sub-acute toxicity study
The toxicity study was performed in Wistar rats by oral administration. An acute toxicity study was done at the dose of 2000 mg/kg
... administration of extract did not show any toxicologically significant treatment related changes in clinical observations, ophthalmic examination, body weight gain, feed consumption, clinical pathology evaluation, and organ weight. Hematological and serum chemistry parameters were within the normal limits. Terminal necropsy did not reveal any treatment related gross or histopathological findings.
Based on this study, the no-observed-adverse-effect-level of WSE is 2000 mg/kg body weight, the highest level tested.
They didn't actually find the NOAEL level, just that it's some unspecified amount higher than 2 g/kg
Edited by RWhigham, 08 April 2018 - 10:04 PM.