Ashwagandha: Lopresti et al., 2026

A 28-day randomized controlled trial of 60 stressed adults found that 30 mg daily ashwagandha extract reduced self-reported stress and blunted cortisol reactivity to a cold-pressor stressor, though the per-protocol analysis missed significance and most secondary outcomes showed no difference. This is a small, preliminary trial with enough rigor to justify larger trials, but not enough power to change behavior yet.

Key takeaways

• The full analysis set showed statistically significant stress reduction (p = 0.046), but the per-protocol analysis — which excluded dropouts — did not reach significance, a sign the effect may be fragile
• Cortisol reactivity to a lab stressor was attenuated in the ashwagandha group (p = 0.047)
• The dose tested — 30 mg daily — is 8-20× lower than the 250-600 mg used in most prior ashwagandha trials, raising questions about dose-response
• The sample size of 60 participants is underpowered for most secondary endpoints, meaning many real effects could have been missed
• The authors call these preliminary findings that support larger trials; this is not definitive evidence to act on

The study

Lopresti and colleagues published this trial in Advances in Therapy in 2026 (PubMed). They recruited 60 adults aged 18-65 with self-reported stress, randomized to receive either 30 mg daily of a proprietary ashwagandha extract (Ashwa.30™) or placebo for 28 days. The trial was double-blind and pre-registered on the Australian and New Zealand Clinical Trials Registry. Outcomes included the Depression, Anxiety, and Stress Scale (DASS), daily mood ratings, and the Chalder Fatigue Scale. On Days 7 and 28, participants underwent the Socially Evaluated Cold-Pressor Test (SECPT) — a validated lab stressor where you submerge your hand in ice water while being watched — during which researchers measured subjective stress, salivary cortisol, chromogranin A, heart rate, skin conductance, and temperature. The duration was short at 28 days, but appropriate for cortisol reactivity endpoints. Demographic details were limited in the abstract.

How to read this study

What this paper does well: The authors pre-registered the protocol, conducted a double-blind RCT, and used both self-report and physiological measures. The SECPT is a validated acute stressor, and measuring cortisol reactivity to it — rather than just baseline cortisol — is a stronger design choice. They analyzed both the full analysis set (intent-to-treat, including all randomized participants) and the per-protocol set (excluding dropouts and non-compliers), which is honest reporting. The 28-day duration is reasonable for stress perception and cortisol response.

What this paper is missing or weak on: The sample size of 60 is small. For many secondary endpoints — fatigue, anxiety, depression, cardiovascular measures — this trial was underpowered, meaning real effects could easily have been missed. The dose of 30 mg is a tenth of what most prior ashwagandha trials use, and the authors don't establish whether this extract is uniquely bioavailable or whether the low dose is simply underdosing. The full analysis set reached significance for stress (p = 0.046), but the per-protocol analysis did not, which raises the possibility that dropouts or non-adherence influenced the result. The trial was funded by Natural Remedies Pvt Ltd, which makes the extract, and five of the seven authors are its employees; the paper states the funder was not involved in data collection or interpretation. That is worth weighing for a proprietary extract trial.

How I'd weight this paper: I treat this as a well-executed preliminary trial that justifies a larger trial, not as evidence to change behavior. The cortisol reactivity finding is interesting — stress perception and cortisol both moved in the same direction, which strengthens the signal. But the small sample, underpowered secondaries, and reliance on a proprietary extract at a dose far below established ranges mean I'd want replication before trusting this dose. If you're already taking 250-600 mg of a standardized ashwagandha extract based on prior evidence, this doesn't change that. If you're not, this doesn't justify starting at 30 mg.

What they found

In the full analysis set, the ashwagandha group showed greater reductions in DASS stress scores than placebo (p = 0.046). Mean daily stress ratings were also lower in the ashwagandha group across the 28 days (p = 0.043). During the SECPT on Day 28, participants receiving ashwagandha reported lower subjective stress ratings during the cold-pressor task (p = 0.044). Salivary cortisol concentrations remained stable in the ashwagandha group during the SECPT, but increased in the placebo group, suggesting blunted cortisol reactivity (p = 0.047). No statistically significant differences were detected for anxiety, depression, fatigue, chromogranin A, heart rate, skin conductance, or skin temperature. The per-protocol analysis — excluding participants who dropped out or were non-adherent — showed directionally consistent results for stress but did not reach statistical significance.

What it means for the average man

If you experience chronic low-grade stress — the kind that shows up as irritability, tension, or feeling on edge — this study suggests a very low dose of ashwagandha might take the edge off. The cortisol reactivity finding is notable: your body's stress response to an acute challenge was dampened, not just your subjective perception. That's mechanistically consistent with prior ashwagandha research. But the dose here — 30 mg — is far below what most evidence supports. The bulk of the ashwagandha literature uses 250-600 mg daily of standardized extracts, and those trials show larger, more consistent effects on stress, cortisol, and testosterone. This trial doesn't tell you whether 30 mg is "enough" or whether a higher dose would perform better. The practical takeaway: if you're already taking ashwagandha at an established dose, this study doesn't change that. If you're considering starting, the evidence still points to 250-600 mg of standardized extracts as the range with the most support.

The caveats

The trial was small and underpowered for most endpoints. The per-protocol analysis missed significance for the primary outcome, which weakens confidence that the effect is robust. The dose is an outlier — most trials use 8-20× more — and the authors don't explain whether this extract has unique bioavailability or whether they simply tested a low dose. The trial was funded by the extract's manufacturer, and five of the seven authors are its employees, which matters for a proprietary extract. The sample was stressed but otherwise healthy adults, so generalizability to clinical populations (e.g., diagnosed anxiety disorders, chronic fatigue) is unknown. The 28-day duration is reasonable for cortisol reactivity but shorter than the 6-8 weeks the authors say most ashwagandha trials have used. Replication in a larger, adequately powered trial is needed before treating this dose as established.

Frequently asked questions

Related reading: Does Ashwagandha Raise Testosterone? Here's What Studies Show. Disclosure: Brookhaven makes Total Men's Package, which contains 300 mg ashwagandha whole herb (5% withanolides) per 7-capsule serving. That is a different preparation and dose from the Ashwa.30™ extract tested in this trial.

Sources

• Lopresti A, Smith S, Bethapudi B, et al. An Examination into the Anti-stress and Anti-fatigue Effects of an Ashwagandha Extract (Ashwa.30™) in Stressed Adults: A Randomised, Double-Blind, Placebo-controlled Trial. Adv Ther. 2026. PubMed
• Chandrasekhar K, Kapoor J, Anishetty S. A prospective, randomized double-blind, placebo-controlled study of safety and efficacy of a high-concentration full-spectrum extract of ashwagandha root in reducing stress and anxiety in adults. Indian J Psychol Med. 2012;34(3):255-262.

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