Ashwagandha KSM-66®
stress
Ashwagandha (Withania somnifera) is an adaptogenic herb with a 3,000-year history in Ayurvedic medicine. An adaptogen helps your body resist and recover from various stressors—physical, chemical, or psychological.
We use KSM-66®, widely regarded as one of the most researched ashwagandha extracts available. It’s a full-spectrum root extract standardized to 5% withanolides (the active compounds) through a process that took 14 years to develop and maintains the natural balance of the root’s components.
The statements on this page have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Ashwagandha Benefits — What Studies Found
Chronic stress suppresses testosterone and stalls recovery. KSM-66® ashwagandha helps break the cycle at the source.
Cortisol & Stress Relief
CortisolTestosterone Support
Testosterone (Men)Strength & Recovery
PerformanceWhy a 400mg dose of Ashwagandha KSM-66®
Clinical studies showing benefits typically use 300–600mg of KSM-66® daily.
- Research-Range Dose 400mg sits within the 300–600mg range used in clinical studies on KSM-66®.
- Full-Spectrum Root Extract Standardized to 5% withanolides through a process that preserves the root's natural constituent balance.
- Formula-Balanced Amount Calibrated for a multi-ingredient formula so it supports stress adaptation without over-competing.
- Consistent With Trial Doses Matches the dosing used in randomized controlled trials examining cortisol, testosterone, and exercise performance.
We chose KSM-66® over other ashwagandha forms because it has the most clinical research, uses a proprietary extraction method that preserves the natural constituent balance, and has consistent quality standards.
The Clinical Sweet Spot
Clinical studies showing benefits use 300–600mg of KSM-66® daily. Our 400mg dose sits comfortably in the effective range.
Three millennia of traditional use, and the mechanism still holds up: lower cortisol so everything downstream — testosterone, recovery, drive — has room to work.
01
Testosterone & Cortisol: Meta-Analysis of 23 Trials
Hormonal Modulation with Withania somnifera: Systematic Review and Meta-Analysis of RCTs. Planta Medica (2026).
Source
Testosterone & Cortisol: Meta-Analysis of 23 Trials
Hormonal Modulation with Withania somnifera: Systematic Review and Meta-Analysis of RCTs. Planta Medica (2026). Source
The strongest evidence to date: a 2026 meta-analysis pooling 23 randomized controlled trials (1,706 participants) found ashwagandha raised testosterone in men by an average of 57 ng/dL and significantly lowered cortisol (pooled SMD -1.18). (No testosterone effect was seen in women.) This places the individual trials below on firm, pooled footing.
02
Spermatogenesis and Testosterone (KSM-66®)
Ambiye VR, et al. (2013). Evidence-Based Complementary and Alternative Medicine.
Source
Spermatogenesis and Testosterone (KSM-66®)
Ambiye VR, et al. (2013). Evidence-Based Complementary and Alternative Medicine. Source
A pilot study using KSM-66® in oligospermic (subfertile) men found significant improvements in sperm concentration (167%), motility (57%), and semen volume (53%) alongside a 17% increase in serum testosterone over 90 days. These results are specific to men with fertility issues — effects in healthy men would likely be smaller.
03
Testosterone in Men
Lopresti AL, et al. (2019). American Journal of Men's Health.
Source
Testosterone in Men
Lopresti AL, et al. (2019). American Journal of Men's Health. Source
A randomized controlled trial in overweight men (aged 40-70) showed ashwagandha supplementation significantly increased testosterone levels (by approximately 15%) compared to placebo. (Note: this study used Shoden extract, not KSM-66®. KSM-66® has demonstrated comparable testosterone effects in other trials — see Ambiye et al.)
04
Cortisol Reduction
Chandrasekhar K, et al. (2012). Indian Journal of Psychological Medicine.
Source
Cortisol Reduction
Chandrasekhar K, et al. (2012). Indian Journal of Psychological Medicine. Source
In a randomized, double-blind trial, ashwagandha supplementation reduced serum cortisol by approximately 28% from baseline in chronically stressed adults. This cortisol-lowering effect is one of ashwagandha’s most consistent findings across studies. A 2026 meta-analysis of 23 trials confirmed this cortisol-lowering effect (pooled SMD -1.18).
05
Exercise Performance
Wankhede S, et al. (2015). Journal of the International Society of Sports Nutrition.
Source
Exercise Performance
Wankhede S, et al. (2015). Journal of the International Society of Sports Nutrition. Source
An 8-week randomized, double-blind trial found that the ashwagandha group achieved 74% greater bench press gains, 48% greater leg extension gains, and 62% greater muscle size gains compared to placebo. These are relative comparisons between groups — not absolute increases. The ashwagandha group also showed reduced exercise-induced muscle damage and increased testosterone in healthy young male subjects.
06
Anxiety and Stress Reduction
Pratte MA, et al. (2014). Journal of Alternative and Complementary Medicine.
Source
Anxiety and Stress Reduction
Pratte MA, et al. (2014). Journal of Alternative and Complementary Medicine. Source
A systematic review found consistent evidence for ashwagandha’s ability to reduce stress and anxiety symptoms, with effects occurring within weeks of supplementation. Two 2025-2026 meta-analyses now pool this evidence: ashwagandha significantly reduced anxiety, stress, and depression symptoms across dozens of randomized trials.
07
Sleep Quality
Langade D, et al. (2021). Journal of Ethnopharmacology.
Source
Sleep Quality
Langade D, et al. (2021). Journal of Ethnopharmacology. Source
Research shows ashwagandha can improve sleep quality and reduce sleep onset latency, particularly in people with insomnia or stress-related sleep issues. A 2025 systematic review (BJPsych Open) found a robust improvement in sleep quality (SMD -1.35), and a 2024 RCT confirmed better subjective sleep at 250-600 mg.
Published Research
153 studiesEvery claim we make is grounded in peer-reviewed research. Tap any study to read the abstract.
Our Assessment: Ashwagandha KSM-66®
Strong, now meta-analysis-backed evidence for cortisol and stress reduction; testosterone support in men is real but modest. KSM-66® is one of the most researched adaptogens available.
- Cortisol reduction is well-documented across multiple studies
- Stress and anxiety benefits are consistent in the literature
- KSM-66® specifically has extensive clinical research
- Testosterone increase is demonstrated in multiple male populations
- Exercise performance benefits are supported by randomized trials
- Safety profile is well-established at recommended doses
- Individual response varies—not everyone responds equally
- Effects on already-healthy individuals with low stress may be less pronounced
- Long-term effects beyond 8-12 weeks are less studied
- Mechanism of testosterone increase isn’t fully understood
How Ashwagandha KSM-66® Fits the Formula
No ingredient works alone. Ashwagandha KSM-66® was chosen because it amplifies — and is amplified by — specific formula partners.
Testosterone Support
Ashwagandha’s cortisol-lowering effect may create a better hormonal environment for the testosterone-supporting ingredients (fenugreek, tongkat ali, zinc, boron) to work. Lower stress means better hormone signaling throughout the body.
Cellular Energy
Chronic stress depletes cellular energy. By supporting stress resilience, ashwagandha complements the cellular energy benefits of NMN and PQQ.
B6
Vitamin B6 supports neurotransmitter production involved in stress response. The combination provides nutritional and adaptogenic support for stress management.
Safety and Precautions
Always consult with a healthcare professional before starting any new dietary supplement, especially if you have an existing medical condition or take prescription medications.
