Benefits
Lower stress scores, in trials of plain ashwagandha
The evidence here is for ashwagandha in general, not for Zenroot. A 2024 systematic review pooled 9 randomized trials and 558 people and found lower Perceived Stress Scale scores with ashwagandha than placebo (average 4.72 points lower, 95% confidence interval 0.99 to 8.45 points). A separate randomized trial in 130 healthy adults also reported lower perceived stress and cortisol, but that capsule contained 5 mg of piperine (black pepper extract) alongside 500 mg of ashwagandha, so the result cannot be credited to ashwagandha alone. None of these studies used 125 mg a day and none named Zenroot. OmniActive's own 12-week study of the 125 mg dose is not among the references cited here.
Modestly better sleep, at doses higher than this one
A 2021 systematic review pooled 5 randomized trials and 400 participants and found a modest improvement in overall sleep quality with ashwagandha (standardized mean difference 0.59, 95% confidence interval 0.42 to 0.75). The effect was clearer in adults who already had insomnia, at doses of 600 mg a day or more, and over 8 weeks or longer. The pooled trials were small and several were funded by ingredient makers. None tested 125 mg a day and none tested Zenroot.
Absorption: a manufacturer claim, not a published outcome
OmniActive reports a single-dose crossover study in which 125 mg of Zenroot produced higher withanolide levels in the blood than larger doses of two other ashwagandha extracts. That study is not among the peer-reviewed references cited on this page, so its methods and funding cannot be checked. Two things worth knowing either way: an absorption measurement is not a health outcome, and no published trial has shown that 125 mg of this extract does what 600 mg of ordinary ashwagandha did in the pooled sleep and stress trials.
Anxiety and mood measures
In the 2024 pooled analysis, ashwagandha lowered Hamilton Anxiety scores by an average of 2.19 points versus placebo (95% confidence interval 0.55 to 3.83 points), a small difference. A 2024 randomized placebo-controlled trial also reported improvements in some mood and cognitive performance measures after ashwagandha, in a small, industry-supported study. Again, these were plain ashwagandha extracts at higher doses, not Zenroot at 125 mg.
Root-only sourcing, and why it is not a safety guarantee
European regulators have raised concerns about ashwagandha leaves and aerial parts, which contain more withaferin A, and root-only extracts are the traditional Ayurvedic preparation. That is a real point in this product's favor for sourcing. It is not proof of liver safety: the US National Institutes of Health LiverTox database records 23 cases of clinically apparent liver injury attributed to ashwagandha, typically appearing as cholestatic hepatitis about a month after starting, and a separate published case series describes serious liver injury from single-ingredient ashwagandha products. Read the safety section before using this or any ashwagandha long term.
A low dose is easier to swallow, but it is a smaller dose
A 125 mg dose fits into gummies, shots and drinks, where the usual 500 to 600 mg ashwagandha doses are hard to hide, and the extract is close to tasteless. That is a practical convenience. Bear in mind that the published evidence for ashwagandha comes from those larger doses, so a smaller, better-absorbed dose is a manufacturer's argument rather than something a published trial has demonstrated.
Mechanism of action
HPA axis modulation
Ashwagandha withanolides modulate the hypothalamic-pituitary-adrenal axis, reducing baseline cortisol and dampening cortisol response to stressors. In the 2024 pooled analysis of 9 trials, serum cortisol was lower with ashwagandha than placebo by an average of 2.58 units (95% confidence interval 0.16 to 4.99), a result that only just reached statistical significance. This is a proposed explanation for the stress and sleep findings, not a proven chain of cause and effect.
GABAergic activity
Laboratory studies suggest withanolides interact with GABA-A receptors, the same receptor family that calming prescription medicines act on. This is a laboratory finding offered as an explanation, not something measured in the human trials cited here, and some people do report feeling drowsy on ashwagandha.
Absorption claim (company data)
OmniActive says its extraction and standardization process yields withanolides that are absorbed better, and reports higher blood levels from 125 mg than from a 600 mg 5% withanolide comparison product. That comparison comes from the company and is not among the peer-reviewed references cited on this page, and better absorption has not been shown to produce equal results at the lower dose.
Antioxidant and anti-inflammatory effects
In cell and animal experiments, withanolides show antioxidant activity and act on inflammatory signaling pathways. Those are laboratory observations. The human trials cited on this page measured stress, anxiety, sleep and mood questionnaires, not inflammation, so this remains a theory rather than a demonstrated benefit.
Clinical trials
Randomized double-blind single-dose crossover comparative oral bioavailability study in 20 healthy adults under fasting conditions.
20 healthy adults
Randomized double-blind single-dose crossover comparative oral bioavailability study in 20 healthy adults under fasting conditions. Three arms: Zenroot 125 mg (1.5% withanolides), a 600 mg reference (5% withanolides) and a 500 mg reference (10% withanolides), with blood withanolide levels measured over 24 hours. The company reports that 125 mg of Zenroot gave 2.1 times higher absorption than the 600 mg reference and 1.3 times higher than the 500 mg one. Limitations to weigh: only 20 people, a single dose, and no published version of this study appears among the references cited on this page, so its methods and funding cannot be checked. It also measured blood levels only. It did not measure stress, sleep or anything you would feel.
12-week randomized double-blind placebo-controlled trial in 90 adults aged 18-55 with mild-to-moderate stress. Intervention: 125 mg/day Zenroot or placebo.
90 adults aged 18-55 with mild-to-moderate stress
12-week randomized double-blind placebo-controlled trial in 90 adults aged 18-55 with mild-to-moderate stress. Intervention: 125 mg/day Zenroot or placebo. The company reports lower Perceived Stress Scale scores and skin-response readings within 30 days, better sleep quality by day 28, and improvements in mood and occasional anxiety over 12 weeks, all versus placebo, in 90 adults. Conducted at Bengaluru Neuro Center, Santosh Hospital. Important limitation: this study is not among the peer-reviewed references cited on this page, so its methods, funding and results cannot be independently checked. Treat it as manufacturer-reported until it is published. The published evidence on this page is for plain ashwagandha at higher doses, not for Zenroot at 125 mg.