Everything about KSM-66® Ashwagandha — the most clinically studied form. Published RCTs, clinical dose, mechanism and how it compares to generic ashwagandha.
⚡ Quick AnswerLast Reviewed: July 2026
KSM-66® is the most clinically studied form of ashwagandha (Withania somnifera). It is a full-spectrum root extract standardised to minimum 5% withanolides with 22+ published human clinical trials. The clinical dose is 600mg daily. Multiple RCTs confirm cortisol reduction (~28%), testosterone support (+17%) and stress relief.
What Is KSM-66® Ashwagandha?
KSM-66® is a patented, full-spectrum ashwagandha root extract manufactured by Ixoreal Biomed. It is standardised to a minimum of 5% withanolides — the active compounds responsible for ashwagandha's adaptogenic effects. Unlike generic ashwagandha root powder or low-standardisation extracts, KSM-66® uses a proprietary extraction process that preserves the full-spectrum alkaloid and withanolide profile.
Published Clinical Evidence
Chandrasekhar et al. (2012) — 27.9% cortisol reduction, significant stress score improvements vs placebo at 600mg/60 days
Ambiye et al. (2013) — 17% testosterone increase, significant sperm quality improvement vs placebo
Wankhede et al. (2015) — Greater testosterone, strength and muscle recovery in trained men vs placebo
Langade et al. (2019) — Significant sleep quality improvements including sleep onset latency
Generic ashwagandha root powder is typically 1-2% withanolides (vs 5% minimum for KSM-66®). Low-standardisation extracts at common supplement doses of 150-300mg provide insufficient withanolide content to replicate the clinical trial results. The published evidence specifically applied to KSM-66® at 600mg daily cannot be assumed to apply to generic alternatives.
KSM-66® is a patented full-spectrum ashwagandha root extract standardised to minimum 5% withanolides, with 22+ published human clinical trials. The most studied form of ashwagandha available.
600mg daily — the dose used in the most-cited published RCTs. Doses below 300mg are unlikely to produce the studied effects.
KSM-66® is standardised to 5%+ withanolides using a proprietary extraction process. Generic ashwagandha is typically 1-2% withanolides at uncontrolled potency.
Testosil®, TestRX® and CortiSync all contain KSM-66® at 600mg — the clinical dose. Many products include ashwagandha but not in the KSM-66® form or at adequate dose.
Well-established safety profile across 22+ human clinical trials at the 600mg dose. Consult GP if taking prescription medication.
Disclaimer: For informational purposes only. Dietary supplements — not medicines. Not intended to diagnose, treat, cure or prevent any disease. FDA/MHRA not evaluated. Individual results vary. Consult healthcare professional. Affiliate commissions may be earned. Full disclaimer →