KSM-66® has been investigated in human trials on stress and sleep. Here, we look at two studies, their results, and their limitations. They evaluated an ingredient, not the complete Essence of Night™ formula. A daily amount can match a study while the dosing schedule, population, and finished product remain different.
01 / The ingredient
A botanical with a specific identity
Ashwagandha is a shrub used in Ayurvedic traditions. KSM-66® is a branded extract made from its roots. Root, leaf, and combined extracts can differ; results from one preparation should not automatically be transferred to another.[3]
02 / Human research
What happened in the sleep study?
A 2019 randomized, double-blind trial assigned 60 adults with insomnia to 300 mg twice daily or placebo for 10 weeks; 58 completed it. A wrist activity monitor estimated sleep.[1]
| Week 10 measure | KSM-66® | Placebo | Group comparison |
|---|---|---|---|
| Time to fall asleep | 29.00 min | 33.95 min | p = .019 |
| Sleep efficiency | 83.49% | 79.68% | p < .0001 |
| Total sleep time | 311.62 min | 292.37 min | Not significant; p = .076 |
| Awake after sleep onset | 33.05 min | 40.00 min | Not significant; p = .076 |
These are averages among completers. Sleep efficiency means the proportion of time in bed spent asleep. The study supports a difference in falling asleep and sleep efficiency; it does not establish longer sleep or fewer nighttime awakenings. It was small and conducted at one center. The authors reported no financial support and acknowledged Ixoreal supplied the ingredient.
03 / Human research
Stress is another part of the picture
A 2012 randomized, double-blind, placebo-controlled trial enrolled 64 adults with chronic stress. Participants took concentrated ashwagandha root extract, 300 mg twice daily, for 60 days; 61 completed the trial. Perceived stress scores improved more than with placebo (p < .0001). Serum cortisol also declined more.[2]
The trial did not measure nighttime cortisol patterns, estrogen balance, or menopause symptoms. Stress questionnaires and a blood measurement answer different questions. This was a small study, and neither trial was designed specifically for women after 35.
04 / Our serving
600 mg, with the context included
Essence of Night™ provides 600 mg per two-capsule serving, the same daily total used in these studies. Both trials divided it into two servings; our directions recommend an evening serving. Matching the daily amount does not establish equivalent effects from a different schedule or from an eight-ingredient formula.
For an individual reader, a group average is a useful reference rather than a promised result. A statistically significant finding also does not tell us how noticeable a change will feel.
05 / Useful questions
What should I know about safety?
Ashwagandha may cause drowsiness or digestive upset, and rare liver injury has been reported. Avoid it during pregnancy or breastfeeding. NIH guidance does not recommend it for people with thyroid or autoimmune disorders or before surgery. It may interact with medicines, including sedatives and thyroid medication. Discuss suitability with a clinician; long-term safety remains uncertain.[3]
KSM-66® is not melatonin. An ashwagandha extract and the hormone involved in sleep timing are different substances.
References
Sources
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[1] Langade et al. 2019. Cureus. Ashwagandha sleep trial.
Randomized controlled trial. Sleep values above follow the full-paper Tables 2 and 8. DOI: 10.7759/cureus.5797.
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[2] Chandrasekhar et al. 2012. Indian Journal of Psychological Medicine. Stress trial.
Indian Journal of Psychological Medicine, 34(3), 255-262. DOI: 10.4103/0253-7176.106022.
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[3] NIH NCCIH. Ashwagandha ingredient and safety guidance.
Ingredient and safety overview. Accessed October 18, 2026.
Linked studies examine individual ingredients or specific preparations, rather than the complete Essence of Night™ formula. *These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.