RCTJadad 5/5RandomizedDouble-BlindPlacebo-Controlled

Ashwagandha for Stress and Testosterone: What This 60-Day Trial on the "Shoden" Extract Actually Found

MedicineSeptember 1, 2019Vol. 98 (37)

Summary

If you've scrolled past an ashwagandha ad promising "lower cortisol, less anxiety, more testosterone" in the last few years, this 2019 study is one of the trials behind those claims — and it's worth understanding exactly what it did and didn't show. Researchers in India ran a 60-day, randomized, double-blind, placebo-controlled trial in 60 healthy adults (37 men, 23 women, ages 18–65) who reported mild-to-moderate stress and anxiety. Half took 240 mg/day of a standardized ashwagandha root extract branded Shoden (concentrated to 35% withanolide glycosides, the plant's active steroidal compounds); half took a look-alike placebo capsule made of roasted rice powder. Neither participants nor staff knew who got what.

This is a smaller dose than most ashwagandha research — many prior trials used 600 mg/day of less-concentrated extract, so Shoden's higher withanolide percentage let researchers test a much lower milligram amount. That distinction matters when you're comparing label doses at the pharmacy.

The headline results: anxiety, measured by a clinician-administered scale (HAM-A), dropped 41% in the ashwagandha group versus 24% with placebo — a statistically significant difference (p=.040). A self-reported stress/anxiety/depression questionnaire (DASS-21) improved more with ashwagandha too (30% vs 10%) but just missed the conventional significance cutoff (p=.096). On the hormone side, morning cortisol fell 23% in the ashwagandha group versus a negligible 0.5% uptick with placebo (p<.001), and DHEA-S (another adrenal stress hormone) dropped 8% versus a slight rise on placebo (p=.004) — both effects held up in men and women separately. Testosterone rose 11% in men taking ashwagandha (a real within-group effect, p=.038), but placebo men barely moved either, and the group-vs-group comparison didn't reach statistical significance (p=.158) — likely because only 37 men total were split across two arms, too few to detect that size of difference reliably. Women saw no testosterone change either way. Everyone finished the trial, no one reported an adverse event, and blood counts and cholesterol markers were unchanged — a genuinely clean tolerability profile.

Since this trial published, larger 2024–2025 meta-analyses pooling multiple ashwagandha studies have converged on a similar pattern: cortisol reliably comes down, but effects on subjectively perceived stress are more mixed and modest than headlines suggest — so treat "more cortisol drop" as the most reproducible finding, and "cures anxiety" as an overstatement of the current evidence.

What This Means For You

If you're considering an ashwagandha supplement for stress, this trial supports a starting point of 240 mg/day of a concentrated extract (35% withanolide glycosides, ~84 mg active withanolides) taken once daily after food, for at least 4–8 weeks before judging effect — the between-group anxiety benefit here only became significant by day 60, not earlier timepoints. Because commercial products vary enormously (5% withanolide "full-spectrum" extracts at 600 mg vs. 35% concentrated extracts at 120–240 mg), check the label for both the standardization percentage and the milligram dose, not just "ashwagandha 600 mg" — a lower headline number can still deliver more active compound. Look for the same extraction method (ethanol:water) and third-party standardization data on the certificate of analysis if the brand publishes one.

Who might benefit most: adults with mild, self-reported stress/anxiety rather than a diagnosed anxiety disorder — that's who was studied here. Men interested in the testosterone finding should read it as a modest, statistically-fragile signal (significant only within the treatment group, not clearly better than placebo) rather than a proven T-booster effect; don't expect gym-level performance changes from this alone.

Who should be cautious: pregnant or breastfeeding people, anyone with thyroid disease (ashwagandha can increase thyroid hormone levels), those on sedatives, thyroid medication, immunosuppressants, or diabetes medication, and anyone with existing liver disease — regulators in Australia and elsewhere have flagged rare but real cases of ashwagandha-associated liver injury since 2024 (see Caveats). Cost-wise, concentrated extracts like Shoden or KSM-66 cost more per capsule than generic ashwagandha powder, but this study's dosing (240 mg once daily) is inexpensive relative to most stress supplements — roughly $10–25/month at typical retail pricing.

Important Considerations

This was a small trial (30 per group) run at two clinics in India in adults with mild self-reported stress — not a clinical population with diagnosed anxiety or depression, and not necessarily representative of other diets, climates, or genetics. The study was funded by Arjuna Natural Ltd, the manufacturer of Shoden, and one author had a prior financial relationship with the company — a common pattern in supplement research that doesn't invalidate the data but warrants extra scrutiny of the reported effect sizes. The primary self-report measure (DASS-21) didn't reach statistical significance, and the testosterone finding — the one most likely to be marketed aggressively — was not significantly different from placebo between groups, only within the treatment group over time; treat any ad claiming "boosts testosterone" as an overstatement of what this study actually showed. The trial only ran 60 days, so nothing here tells you about long-term safety, whether benefits persist after stopping, or whether cortisol/DHEA-S changes actually translate into meaningful daily-life improvements — the researchers themselves note they couldn't link hormone changes to symptom relief. It was also retrospectively registered (registered after enrollment began), a methodological flag worth knowing about. Separately, and after this paper published, regulators including Australia's TGA issued 2024 safety alerts about rare ashwagandha-associated liver injury; anyone with liver disease, on multiple medications, or noticing symptoms like jaundice, dark urine, or unusual fatigue after starting ashwagandha should stop and consult a doctor. As always, talk to a healthcare provider before starting any new supplement, especially if pregnant, on thyroid or psychiatric medication, or managing a chronic condition.

Terms Explained

WithanolidesThe main active steroidal compounds in ashwagandha root, believed responsible for its stress-relieving and hormonal effects; supplement labels often list a withanolide percentage as a potency marker.
Standardized extractA supplement extract processed and tested to guarantee a consistent percentage of an active compound (here, 35% withanolide glycosides) batch to batch, unlike raw or 'full-spectrum' powders.
HAM-A (Hamilton Anxiety Rating Scale)A 14-item, clinician-administered questionnaire that scores the severity of anxiety symptoms; lower scores mean less anxiety.
DASS-21A 21-item self-report questionnaire measuring symptoms of depression, anxiety, and stress; used alongside clinician ratings to capture how participants themselves feel.
CortisolThe body's primary stress hormone, released by the adrenal glands; chronically elevated morning cortisol is commonly used as a biological marker of stress.
DHEA-SDehydroepiandrosterone-sulfate, another adrenal hormone that tends to rise with acute stress; the study used its reduction as a secondary sign of lowered stress-axis activity.
HPA axis (hypothalamic-pituitary-adrenal axis)The body's central stress-response system linking the brain and adrenal glands; researchers believe ashwagandha may work partly by calming this system's activity.
Double-blind, placebo-controlled trialA study design where neither participants nor researchers know who receives the real treatment versus a fake (placebo) pill, reducing bias in reported results.
Statistical significance (p-value)A measure of how likely a result occurred by chance; a p-value below .05 is conventionally called 'statistically significant,' meaning the result probably wasn't a fluke.
Intention-to-treat analysisA method of analyzing results that includes all randomized participants in their original group, which here didn't matter much since no one dropped out.
Technical Study Details

Study Design

RegistrationClinical Trials Registry - India (CTRI): CTRI/2017/08/009449

Total Score

JADAD Quality Assessment
5
/ 5

評価詳細

Randomization

2 / 2
Is the study described as randomized?
Yes+1
Rationale: The article repeatedly and explicitly describes the study as "randomized" (e.g., "randomized, double-blind, placebo-controlled study/trial"), and also details the randomization process ("randomly allocated," "randomized into 1 of 2 treatment conditions" using "a random number table").
Is the method of randomization described and appropriate?
Yes+1
Rationale: The article explicitly describes the randomization method as use of a random number table, which is a recognized appropriate method of randomization, satisfying the Jadad criterion for Q2.

Blinding

2 / 2
Is the study described as double-blind?
Yes+1
Rationale: The article explicitly and repeatedly describes the study as "double-blind" in the abstract, methods (study design), and discussion sections.
Is the method of blinding described and appropriate?
Yes+1
Rationale: The article explicitly describes the blinding method: the ashwagandha and placebo capsules were identical in appearance, shape, color, and packaging (oblong green-colored capsules), which is an appropriate double-blinding technique (indistinguishable placebo) consistent with Jadad criteria for appropriate blinding.

Dropouts/Withdrawals

1 / 1
Is there a description of dropouts and withdrawals?
Yes+1
Rationale: The article explicitly states that all 60 enrolled participants (37 males, 23 females) completed the 60-day trial with no missing data, and reiterates in the results/adverse events section that all participants completed the study. This constitutes an explicit description of withdrawals/dropouts (i.e., zero withdrawals) accounted for across the sample, satisfying the Jadad criterion.</rationale> </invoke>

Study Population

Sample Size60
Age Range18-65 years
ConditionSelf-reported high/mild stress and anxiety in healthy adults (HAM-A 6-17)
Inclusion Criteria
  • Healthy male and female adults aged 18-65 years
  • HAM-A score between 6 and 17
  • Willing to participate and comply with study procedures (signed informed consent)
  • Female participants of child-bearing age using an effective contraceptive method and negative pregnancy test
  • Non-child-bearing women postmenopausal for at least 12 consecutive months or surgically sterilized
  • Willing to avoid major lifestyle changes during the study period

Interventions

Ashwagandha extract (Shoden)

Treatment
Dose240 mg capsule (84 mg withanolide glycosides)
FrequencyOnce daily, after dinner
Duration60 days
RouteOral

Placebo

Control
DoseN/A
FrequencyOnce daily, after dinner
Duration60 days
RouteOral

Outcomes

OutcomeTypeEffectp-value
Hamilton Anxiety Rating Scale (HAM-A)Primary-P = .040Significant
Depression, Anxiety and Stress Scale-21 (DASS-21)Primary-P = .096
Serum morning cortisolSecondary-< .001Significant
Serum dehydroepiandrosterone-sulphate (DHEA-S)Secondary-P = .004Significant
Serum testosteroneSecondary-P = .150
Adverse events / tolerabilitySecondary--

Safety

Adverse Events0
Serious AEs0
Dropout Rate0.0%
Ashwagandha was well tolerated with no adverse events reported. All 60 participants completed the 60-day trial. Compliance was high (>90% of allocated capsules consumed, per returned capsule counts at days 15, 30, 45, 60). Pre- and post-hematological measures (full blood count and lipid profile) showed no statistically significant between-group differences over time.

Conclusion

In this 60-day randomized, double-blind, placebo-controlled trial, 240 mg/day of a standardized ashwagandha extract (Shoden) was associated with a statistically significant reduction in anxiety (HAM-A, P=.040) and a near-significant reduction in stress/depression/anxiety symptoms (DASS-21, P=.096) compared with placebo, in healthy adults with self-reported high stress. Ashwagandha also produced significantly greater reductions in morning cortisol (P<.001) and DHEA-S (P=.004) versus placebo, and was associated with a significant within-group increase in testosterone in men (P=.038), though the between-group difference for testosterone did not reach statistical significance (P=.158). No adverse events were reported and all 60 participants completed the trial. The findings suggest ashwagandha's anxiolytic effects may occur via a moderating effect on hypothalamic-pituitary-adrenal axis activity, though larger, more diverse, and longer trials are needed to confirm these findings.

Limitations

  • Study conducted only in healthy adults with mild stress; effects in clinical populations with diagnosed anxiety/affective disorders not examined
  • Study population drawn only from India; findings may not generalize to other cultural populations
  • Did not examine impact of feeding habits, economic conditions, or daily occupation on anti-stress effects
  • Relatively short (60-day) treatment duration; longer-term safety and efficacy not established
  • No follow-up assessment after intake cessation to assess withdrawal effects or sustainability of benefits
  • Small sample size (especially per-gender subgroups, e.g., 37 males) limited ability to detect statistically significant between-group effects for testosterone
  • Could not examine whether hormonal changes (cortisol, DHEA-S, testosterone) were related to symptomatic/clinical improvement
  • Varying ashwagandha extracts, extraction techniques, and dosages used across the field's trials make cross-study comparison and determination of optimal dose difficult
  • Trial was retrospectively registered (registered August 2017 after recruitment occurred April-July 2016)
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Ashwagandha for Stress and Testosterone: What This 60-Day Trial on the "Shoden" Extract Actually Found | Re:Vital Nexus