Low dose ashwagandha extract shows higher bioavailability and stress relief in clinical studies

Two recently published studies examined the bioavailability of the ashwagandha (Withania somnifera) extract Zenroot and its effect on sleep and stress. The root-only extract from OmniActive is standardized 1.5% withanolides and can be formulated for use in gummies, shots, and functional beverages. Both studies were published in August in Advances in Therapy.

How does the bioavailability of Zenroot compare to other ashwagandha extracts?

The study, “Superior Bioavailability of a Novel 1.5% Ashwagandha Formulation (Zenroot™): A Randomized, Double-Blind, Single-Dose, Comparative, Oral Bioavailability Study in Healthy Adults,” involved 20 adult participants under fasting conditions who were given a single dose of three ashwagandha extracts: ZEN 1.5 (Zenroot Ashwagandha 1.5% 125 mg), ASH 5 (Ashwagandha 5% 600 mg) and ASH 10 (Ashwagandha 10% 500 mg)¹. Measurements were taken at several time points within 24 hours for total withanolides.

At a 125 mg dose, Zenroot demonstrated 2.1–fold higher bioavailability compared to ASH 5 and 3.1-fold higher bioavailability compared to ASH 10. Compared to ASH 5, participants in the Zenroot group showed higher total withanolides in plasma concentrations at all time points except 12 and 24 hours, and when compared to ASH 10, the participants showed higher total withanolides at 0.25, 1, 2, 3, and 4 hours. The extract was also well-tolerated throughout the study, the abstract notes.

“To our knowledge, this is the most comprehensive bioavailability study of ashwagandha extract in human volunteers,” stated Abhijeet Morde, divisional vice president of clinical research at OmniActive, in a September 3 press release². “By measuring individual withanolides (withanoside IV, withanolide A, 12-deoxywithastramonolide, and withaferin A) as per FDA guidance, we’ve set a new benchmark for ingredient transparency and performance, data that empowers brands to select clinically supported solutions aligned with consumer health goals."

What is Zenroot’s effect on reducing stress and anxiety?

The prospective study, “A New Ashwagandha Formulation (Zenroot™) Alleviates Stress and Anxiety Symptoms While Improving Mood and Sleep Quality: A Randomized, Double-Blind, Placebo-Controlled Clinical Study,” involved 90 participants with non-chronic mild to moderate stress. Participants received either 125 mg of Zenroot or a placebo over an 84-day study period³. Changes in stress, the primary focus of the study, were measured using the Perceived Stress Scale (PSS) score, while other measurements included changes in anxiety using the Beck Anxiety Inventory (BAI) and sleep quality using Pittsburgh Sleep Quality Index (PSQI).

Participants in the Zenroot group demonstrated improvements in multiple categories:

• On days 28, 56, and 84, participants showed significant improvements in PSS, BAI, and PSQI scores compared with the placebo
• On days 14, 28, and 84, improvements were seen in the Mindfield eSense Skin Response (SCR)
• Improvements in Mindfield eSense PULSE Heart Rate Variability (HRV)–Root Mean Square of Successive Differences (RMSSD) were seen on day 14
• Improvements in Profile of Mood States (POMS) were seen on days 56 and 84

Serum cortisol and salivary alpha amylase (sAA) levels were not different between the groups. The extract was also well-tolerated, the abstract noted.

“The ashwagandha category is booming as consumers look for clean label, nonpharmacological solutions to support mood, sleep and stress management,” stated Keya Shah, category manager at OmniActive. “Zenroot’s studies reinforce its ability to deliver a clinically validated, high-performance botanical ingredient that meets these demands in a crowded, fast-growing market. As we continue investing in new science, we see Zenroot as a cornerstone ingredient for formulators seeking to lead in the mental and overall wellness space.”

The press release also notes that the global ashwagandha extract market is expected to grow to $1.79 billion by 2035, according to Future Market Insights, supported by interest from younger US consumers in adaptogens in functional formats.

Earlier this year, Zenroot and another plant-based ingredient from OmniActive, Sleeproot, were launched in European markets⁴. Both aim to support sleep, stress, and mood.

References

1. Ramapalaniappan, A., Loganathan, V., Morde, A. Padigaru, M.; Patni, P.; Joshua, L.; Thomas, JV. Superior Bioavailability of a Novel 1.5% Ashwagandha Formulation (Zenroot™): A Randomized, Double-Blind, Single-Dose, Comparative, Oral Bioavailability Study in Healthy Adults. Adv Ther 2025. DOI: 10.1007/s12325-025-03292-7
2. OmniActive. Two New Peer-Reviewed Studies on Zenroot https://omniactives.com/press-releases/two-new-peer-reviewed-studies-on-zenroot/ (accessed 2025-09-05).
3. Mahadevan, M., Gopukumar, K., Gupta, R. Morde, A.; Patni, P.; Srinivas, SS.; Bhuvanendran, A.; Phanindra, A. A New Ashwagandha Formulation (Zenroot™) Alleviates Stress and Anxiety Symptoms While Improving Mood and Sleep Quality: A Randomized, Double-Blind, Placebo-Controlled Clinical Study. Adv Ther 2025. DOI: 10.1007/s12325-025-03327-z
4. McEvoy, E. Two ingredients by OmniActive Health Technologies launched in European markets https://www.nutritionaloutlook.com/view/two-ingredients-by-omniactive-health-technologies-launched-in-european-markets (accessed 2025-09-05).