Glossary · Chemistry
Withanolide
Steroidal lactone compounds in Ashwagandha. The fraction standardized extracts (KSM-66, Sensoril) report by percent.
Plain language
The active fraction in Ashwagandha. The percent on the bottle is the number to compare across brands. KSM-66 and Sensoril are the two most-studied standardized extracts.
Definition
Withanolides are a class of naturally-occurring C28 steroidal lactones found primarily in plants of the Solanaceae family, with the highest concentrations in Withania somnifera (Ashwagandha). The total withanolide content is the standard metric on Ashwagandha extract labels: KSM-66 reports approximately 5 percent withanolides, Sensoril reports approximately 10 percent. Most Ashwagandha trials dose by total milligrams of extract at a known withanolide percent.