Ashwagandha Cortisol RCT: Do Clinical Trials Show Lower Cortisol?

Ashwagandha has become a familiar ingredient in supplements marketed for stress management, relaxation, and sleep support. Yet the presence of a botanical ingredient on a product label does not tell you how well it has been studied or whether a particular formulation produces the outcomes reported in clinical research. Cortisol, often called the stress hormone, is essential to normal physiology, and interpreting changes in its concentration requires more than comparing a number before and after supplementation. The most useful evidence comes from controlled human studies that compare a defined preparation with an appropriate control group.

Randomized controlled trials suggest that certain ashwagandha extracts can reduce measured cortisol compared with placebo in some adults experiencing stress. Studies using specific root extracts at 250–600 mg daily for about six to eight weeks have reported favorable results. However, findings differ across preparations and populations, and lower cortisol does not necessarily mean less perceived stress or prove that every supplement delivers the same effect.

That distinction matters when comparing products, reading health claims, or deciding whether a supplement belongs in an everyday routine. One trial may report a substantial percentage reduction, while another may show a different result because the participants, extract, measurement schedule, or study design differs. Understanding those details makes it easier to separate promising findings from conclusions that the evidence cannot yet support.

Do Ashwagandha RCTs Show Lower Cortisol?

Randomized controlled trials have reported lower cortisol levels with certain ashwagandha extracts compared with placebo. The results are encouraging, but they apply to the preparations and participants studied. Current evidence does not establish that every ashwagandha product lowers cortisol, that all users will respond similarly, or that a measured reduction necessarily produces a meaningful improvement in everyday well-being.

What Did Major Clinical Trials Find?

A frequently cited study by Chandrasekhar and colleagues, published in 2012 in the Indian Journal of Psychological Medicine, enrolled 64 adults experiencing chronic stress. Participants were assigned to receive either a concentrated ashwagandha root extract or placebo in a randomized, double-blind study lasting 60 days. The active group received 300 mg twice daily, totaling 600 mg per day. Researchers assessed serum cortisol alongside standardized questionnaires measuring participants' reported stress and anxiety symptoms.

At the end of the study, mean serum cortisol had decreased by 27.9% from baseline in the ashwagandha group, compared with 7.9% in the placebo group. The difference in cortisol changes was statistically significant. The researchers also reported favorable changes in the questionnaire-based outcomes, making the findings relevant to both a biological marker and participants' reported experiences.

The trial nevertheless had limitations. It included a relatively small group of adults, followed them for only two months, and evaluated a particular concentrated root extract. Its results cannot automatically be transferred to other extracts, different daily amounts, or people with different health circumstances. It provides a meaningful piece of human evidence, rather than proof that all ashwagandha supplements produce the same outcome.

Read the 2012 randomized controlled trial.

What Do Recent Meta-Analyses Show?

Systematic reviews and meta-analyses can provide a broader picture by combining results from multiple studies. A 2025 review by Albalawi examined seven studies reporting cortisol outcomes and six reporting perceived stress outcomes, with 488 participants across the included evidence. The pooled cortisol analysis found a mean difference of −1.16 µg/dL in favor of ashwagandha, with a 95% confidence interval from −1.64 to −0.69 µg/dL. This result suggests that the preparations studied were associated with lower measured cortisol compared with control conditions.

The same review, however, did not find a statistically significant pooled improvement in perceived stress scores. The estimated standardized mean difference was −0.355, with a 95% confidence interval from −1.188 to 0.47 and a P value of 0.40. The analysis also reported moderate heterogeneity, with an I² value of 50.9%, indicating meaningful variation among the included study results.

A separate 2026 systematic review and meta-analysis examined 23 randomized trials involving 1,706 participants across several hormonal outcomes. It reported a statistically significant pooled cortisol effect, while also identifying differences between studies and limited data for certain outcomes. Importantly, the 1,706 participants represented the broader hormonal review, not necessarily the number contributing cortisol data alone.

Taken together, these reviews support continued scientific interest in ashwagandha, but they do not eliminate uncertainty about the ideal extract, dose, treatment duration, or likely individual response.

Read the 2025 cortisol meta-analysis and the 2026 hormonal meta-analysis.

Are Results Better Than Placebo?

A placebo-controlled trial helps researchers determine whether a measured change is greater than the change that occurs without the active intervention. This is particularly important in stress research because participants' experiences can shift naturally as workloads, sleep habits, relationships, exercise, and other circumstances change. Without a suitable comparison group, an improvement after starting a supplement cannot confidently be attributed to that supplement alone.

In a 2019 randomized, double-blind trial, Salve and colleagues compared 250 mg and 600 mg of a specific ashwagandha root extract daily with placebo over eight weeks. Sixty adults were randomized, and 58 completed the study. Both ashwagandha groups showed statistically significant reductions in serum cortisol relative to placebo, with the larger change reported in the 600 mg group.

The results provide additional evidence that certain ashwagandha preparations may affect cortisol under controlled study conditions. They do not establish that a higher dose will always produce a better result, because the comparison was conducted with one particular extract in a relatively small population.

Placebo comparisons strengthen the evidence, but the overall conclusion still depends on trial quality, participant characteristics, outcome selection, and consistency across independent studies. A product claim should not be based on a single favorable result while ignoring the limits of the wider research.

Read the 2019 randomized clinical trial.

How Much Did Cortisol Levels Change?

The magnitude of cortisol changes varies across ashwagandha studies. The 2012 trial reported a 27.9% reduction from baseline in its ashwagandha group, while a 2025 meta-analysis estimated a pooled difference of −1.16 µg/dL compared with control. These figures describe different statistical outcomes and should not be treated as interchangeable predictions for an individual or a particular supplement.

What Cortisol Reductions Were Reported?

Percentages make clinical results easier to understand, but they do not tell the whole story. A 25% reduction from a relatively high starting concentration represents a different absolute change from a 25% reduction from a lower starting concentration. To interpret a trial properly, readers need to consider the baseline measurements, final values, placebo response, and variability between participants.

In the 2012 study, mean serum cortisol in the ashwagandha group changed from 15.7 to 11.3 µg/dL over 60 days. The placebo group's mean changed from 15.6 to 14.4 µg/dL. In the 2019 study, the 250 mg/day group changed from 16.30 to 13.61 µg/dL over eight weeks, while the 600 mg/day group changed from 16.12 to 10.86 µg/dL. The placebo group's mean changed from 16.15 to 15.52 µg/dL.

Study group	Baseline serum cortisol	End-of-study serum cortisol	Duration
2012 ashwagandha group	15.7 µg/dL	11.3 µg/dL	60 days
2012 placebo group	15.6 µg/dL	14.4 µg/dL	60 days
2019 ashwagandha, 250 mg/day	16.30 µg/dL	13.61 µg/dL	8 weeks
2019 ashwagandha, 600 mg/day	16.12 µg/dL	10.86 µg/dL	8 weeks
2019 placebo group	16.15 µg/dL	15.52 µg/dL	8 weeks

Values are group means reported in the original trials. They are not target values for consumers, and differences between the study preparations limit direct comparisons.

These figures illustrate why it is important to distinguish a change within a treatment group from the difference between treatment and placebo. A decline from baseline does not by itself prove that a supplement caused the change. Researchers need to assess the comparative effect and its statistical uncertainty before drawing conclusions about the intervention.

How Was Cortisol Measured?

Cortisol can be measured in blood, saliva, or urine, with each method providing different information. The 2012 and 2019 trials discussed above measured serum cortisol using blood samples. Other studies may use salivary cortisol or different collection schedules, which can make the findings difficult to compare directly. The sample type and laboratory method should therefore be considered when interpreting a published result.

Timing is especially important because cortisol follows a daily rhythm. Concentrations are generally higher around waking and decline throughout the day, although the pattern varies with sleep timing and individual physiology. Physical activity, acute illness, disrupted sleep, medication use, and the stress associated with a blood draw can also influence measurements. Researchers try to reduce these effects by standardizing collection conditions across treatment groups and study visits.

Even when collection is carefully controlled, a single result represents a measurement at a particular moment rather than a complete picture of hormone activity throughout the day. A value collected early in the morning should not be casually compared with a value collected later in the afternoon, particularly when the testing conditions are unknown.

For consumers, a cortisol result should be interpreted in the context of the collection time, laboratory reference interval, testing method, and reason for the test. Clinical testing is not a supplement performance scorecard, and decisions about abnormal results belong with a qualified healthcare professional.

Does Lower Cortisol Mean Less Stress?

Lower cortisol does not automatically mean less perceived stress, and lower is not always better. Cortisol plays essential roles in normal physiology, including energy regulation and the body's response to changing demands. A healthy system requires appropriate hormonal activity and daily variation, not simply the lowest possible concentration. A measurement should therefore be interpreted in context rather than treated as an isolated indicator of wellness.

A person may feel better rested after improving sleep habits, managing daily demands, or changing other routines without showing a large difference in a single cortisol measurement. Conversely, a laboratory value may change without a noticeable improvement in everyday experience. These outcomes are not necessarily contradictory because biological markers and self-reported symptoms measure different aspects of health.

The 2025 meta-analysis illustrates this distinction: its pooled cortisol outcome was statistically significant, but its pooled perceived stress outcome was not. This does not prove that ashwagandha cannot influence how people experience stress. Instead, the studies included in that analysis did not establish a statistically significant overall effect on the perceived stress measure they evaluated.

Some individual trials have reported improvements in stress questionnaires, which is one reason the wider evidence needs to be assessed as a whole. The most useful perspective considers laboratory findings alongside sleep quality, daily functioning, perceived stress, and tolerability, without assuming that one result predicts every other outcome.

Which Doses and Extracts Were Studied?

Clinical trials have investigated different ashwagandha preparations and daily amounts, including 250–600 mg of specific root extracts over approximately six to eight weeks. These amounts describe the protocols used in particular studies, not universal dosing recommendations. Extract composition, plant part, standardization, manufacturing methods, and the population being studied all influence how confidently results can be applied to another supplement.

What Daily Doses Were Tested?

Several randomized trials have examined daily amounts within the range of a few hundred milligrams. In the 2012 study, participants received 300 mg of a concentrated root extract twice daily, totaling 600 mg per day. In the 2019 trial, researchers compared 250 mg and 600 mg per day of the studied root extract with placebo. Both doses were associated with favorable cortisol results under the conditions of that particular trial.

These amounts are useful reference points when reviewing the literature, but the milligram figure alone does not establish equivalence between products. A concentrated extract and raw root powder can have different compositions even when a label displays the same number. Similarly, two concentrated extracts may differ in their chemical profiles and standardization specifications.

The 2019 study reported a larger cortisol reduction in the 600 mg group than in the 250 mg group. This is relevant evidence for the preparation tested, but it does not establish a universal dose-response relationship. A higher amount is not automatically more beneficial or suitable for everyone, and individual health circumstances, medication use, and tolerance may influence whether a product is appropriate.

Consumers should not choose a serving amount solely because it matches the largest dose reported in a clinical trial. The actual product formulation, available quality information, directions, and personal circumstances all matter when interpreting the evidence.

How Do Ashwagandha Extracts Differ?

Ashwagandha, botanically known as Withania somnifera, is sold in several forms, including powdered root, concentrated root extract, and preparations containing different plant parts. These materials can differ in their chemical composition and concentrations of naturally occurring constituents. The word "ashwagandha" on two product labels therefore does not establish that the products are equivalent or that they will produce the same outcome.

Some extracts disclose standardization to withanolides, a group of naturally occurring compounds found in the plant. Standardization can help characterize an ingredient, but it does not independently prove clinical effectiveness. The stated percentage, analytical method, extract amount, and specifications all contribute to understanding what a product contains.

KSM-66 is a branded root extract used in some commercial supplements and clinical research. Other branded and non-branded preparations may use different extraction processes, plant parts, or ingredient specifications. Findings from one preparation should not automatically be transferred to another without evidence that the products are sufficiently comparable.

A useful label review checks the botanical name, plant part, extract amount, standardization details, and complete ingredient list. Where available, supplier specifications and certificates of analysis can provide additional information about ingredient identity and consistency. These documents support quality assessment, but they do not replace clinical evidence for a particular health outcome.

How Long Did the Trials Last?

Many frequently discussed cortisol studies lasted approximately six to eight weeks. The 2012 trial ran for 60 days, while the 2019 study followed participants for eight weeks. These periods allowed researchers to investigate changes during sustained use, but they do not establish how quickly every consumer should expect a response or whether the same result would occur after a single serving.

A finding measured after eight weeks cannot support a claim that an ingredient works within 30 minutes. It also cannot establish that the effect persists after supplementation stops or remains unchanged during many months of continuous use. Those questions require different study designs and appropriate follow-up periods.

Longer trials may provide more information about durability and safety, although they introduce challenges involving adherence, changes in participants' routines, and the need to monitor adverse events. Research involving larger and more diverse populations would also help clarify whether results extend beyond the specific groups already studied.

The National Center for Complementary and Integrative Health notes that ashwagandha may be safe for short-term use, up to approximately three months, while available information is insufficient to establish long-term safety. This is a summary of the current evidence, not a guarantee that every preparation is safe for that duration.

Study timelines should be treated as boundaries of the available evidence rather than guaranteed schedules for results or instructions to continue supplementation for a particular period.

Can Results Apply to Different Formulas?

A clinical trial's results can only be applied to another formulation with appropriate caution. A study of a single ashwagandha extract does not establish the effectiveness of a finished supplement that combines ashwagandha with other botanicals, amino acids, minerals, or flavoring ingredients. The complete formulation, ingredient amounts, and delivery format may differ substantially from those used in the original research.

For example, AirVigor Night Calm Liquid Sticks – Blackberry is described as a melatonin-free, ready-to-drink evening formulation containing KSM-66 ashwagandha, L-theanine, magnesium glycinate, chamomile, and lemon balm. Its individual liquid sticks provide a convenient format for people who prefer not to prepare a powder or swallow capsules. These characteristics describe the product's composition and format; they do not establish that the finished formula produces the cortisol changes reported in a single-ingredient clinical trial.

The same principle applies when comparing capsules, powders, gummies, and liquid supplements. A convenient format does not independently demonstrate superior absorption or effectiveness, and a branded ingredient does not prove that the complete product has been clinically tested for every advertised outcome.

Consumers can make a more informed comparison by checking the amount of each active ingredient, serving size, relevant standardization details, directions, warnings, and quality information. When exact amounts are not disclosed or cannot be verified, it becomes more difficult to determine how closely a product matches the preparations used in published research.

How Strong Is the RCT Evidence?

The evidence is promising but not definitive. Multiple randomized controlled trials have reported reductions in cortisol with particular ashwagandha extracts, and meta-analyses have found an overall favorable effect. However, differences in preparation, dose, population, study methods, and duration limit certainty. Current research does not establish one universally effective formula or guarantee that every user will experience the same result.

Were the Trials Large Enough?

Randomized controlled trials are valuable because random assignment helps reduce systematic differences between treatment groups. Double-blinding and placebo controls can further limit the influence of expectations on participant behavior and outcome assessment. These methods strengthen a study, but they cannot eliminate every limitation, especially when relatively few participants are enrolled.

The 2012 trial enrolled 64 adults, while the 2019 study randomized 60 participants and had 58 completers. These studies provided useful human evidence, but they were not large enough to establish the full range of possible responses across different ages, medical histories, medication use, and lifestyles. Their findings should not automatically be generalized to populations that were not represented.

Small studies also have limited ability to identify uncommon adverse events. A trial that reports no serious safety concern over eight weeks cannot establish that a supplement is safe for every person or that rare problems will never occur. Safety assessment requires attention to study duration, adverse-event reporting, and information gathered beyond individual efficacy trials.

Meta-analyses can increase statistical precision by combining results, but a larger pooled sample does not automatically resolve weaknesses shared by the underlying studies. If the trials use different extracts, inconsistent outcome measures, or methods with a risk of bias, the combined findings still require careful interpretation.

The available evidence supports further investigation and informed consumer interest, rather than a definitive claim that ashwagandha will lower cortisol for everyone.

What Explains Differences Between Studies?

Differences between trial results can arise for several reasons. Participants may begin with different levels of perceived stress, sleep disruption, or baseline cortisol. An extract tested in adults reporting persistent stress may not produce the same measured change in a group with different characteristics. Baseline differences can also influence the size of a percentage reduction.

Formulation is another important factor. Root powder, concentrated root extract, and root-and-leaf preparations may have different chemical profiles. Even when two products are standardized, their specifications and amounts of relevant constituents may not be identical. These differences complicate comparisons between trials and make it difficult to identify one universally optimal preparation.

Study methods also matter. Cortisol measurements collected at different times of day may not be directly comparable because the hormone follows a daily rhythm. Different laboratories, sample types, analytical methods, and follow-up schedules can add further variation. Researchers also need to consider whether participants followed the protocol consistently and whether other changes during the trial could have influenced outcomes.

Finally, studies may assess different endpoints. A trial focused on serum cortisol does not answer exactly the same question as one primarily measuring perceived stress, sleep quality, or anxiety symptoms. A statistically significant result for one outcome can coexist with a nonsignificant result for another.

The 2025 meta-analysis reported moderate heterogeneity, with an I² value of 50.9%. This indicates meaningful variation among the included study results but does not identify one specific cause. The findings reinforce the importance of comparing like with like instead of assuming that every ashwagandha preparation has an identical effect.

What Are the Main Research Limitations?

Several limitations deserve attention when interpreting ashwagandha cortisol research. Many trials have relatively small samples and short follow-up periods, while the extracts and daily amounts vary. Differences in cortisol sampling, questionnaire methods, and statistical analysis can also affect the interpretation of results. These issues make it difficult to establish one optimal protocol or confidently predict an individual's response.

Other concerns include incomplete reporting of allocation concealment, possible selective reporting, and uncertainty about whether findings apply to populations not represented in the original trials. Financial relationships and study sponsorship should also be reviewed when disclosed, although funding alone does not determine whether a result is valid. A careful assessment considers the complete study rather than accepting or dismissing it on the basis of one characteristic.

When evaluating a trial, readers can look for several important features:

• Randomization and appropriate blinding.
• A suitable placebo or comparison group.
• Clear identification of the extract and serving amount.
• Consistent measurement and transparent reporting of outcomes.
• A sample size appropriate to the research question.
• Systematic monitoring and reporting of adverse events.
• Independent studies that reproduce similar findings.

The 2025 review judged the overall risk of bias to be generally moderate and noted that some studies lacked adequate allocation concealment. The 2026 hormonal meta-analysis also highlighted heterogeneity and limited data for certain outcomes. These limitations do not erase the observed cortisol reductions, but they define the level of confidence the evidence can support and explain the need for more standardized, longer-term research.

Is Ashwagandha Safe for Everyone?

No. Ashwagandha is not appropriate for everyone, and short-term clinical studies cannot establish universal or long-term safety. Reported adverse effects include digestive upset and drowsiness, while rare cases of liver injury have been linked to ashwagandha supplements. Pregnancy, breastfeeding, thyroid or autoimmune disorders, upcoming surgery, certain cancers, and medication use require particular caution or avoidance.

What Side Effects Have Been Reported?

Ashwagandha is a botanical ingredient, but natural origin does not guarantee that a supplement is free from adverse effects. Reported side effects include drowsiness, stomach upset, diarrhea, and vomiting. Their likelihood and severity may vary between people and preparations, and small clinical trials cannot establish how frequently every possible reaction occurs.

Rare cases of liver injury have also been linked to ashwagandha-containing supplements. These reports do not mean that liver injury is a common outcome, but they are important when evaluating an ingredient that may be used regularly. Symptoms such as yellowing of the skin or eyes, dark urine, persistent nausea, unusual fatigue, or significant abdominal discomfort require prompt medical evaluation rather than an attempt to manage the symptoms with another supplement.

The complete formulation matters as well. A product containing several ingredients may have a different tolerability profile from an isolated ashwagandha extract, and the effects of one ingredient cannot establish the safety of the entire formula. Consumers should review all active ingredients and warnings rather than evaluating only the most prominent botanical on the label.

The National Center for Complementary and Integrative Health notes that ashwagandha may be safe for short-term use of up to approximately three months, while long-term safety remains insufficiently established. This is a summary of the available evidence, not a guarantee that every preparation is safe for three months or that every person can use it without risk.

Who Should Avoid Ashwagandha?

Ashwagandha should be avoided during pregnancy and should not be used while breastfeeding, according to guidance from the National Center for Complementary and Integrative Health. People with thyroid or autoimmune disorders are also advised not to use it without appropriate medical evaluation, because the ingredient may affect thyroid function or immune-related processes. These concerns are especially relevant when a medical condition requires careful monitoring.

People preparing for surgery should avoid ashwagandha unless their healthcare team advises otherwise. Its potential effects and interactions may be relevant to perioperative care. Individuals with hormone-sensitive prostate cancer should also avoid it because ashwagandha may increase testosterone levels, according to NIH guidance.

Those with a history of liver disease or previous supplement-related liver injury should seek professional advice before considering it. These precautions are important because clinical trials often exclude people with complex medical conditions, meaning the evidence from healthier study participants may not apply to them. Limited trial data should not be mistaken for proof of safety in higher-risk groups.

This does not mean that every person with a medical condition will experience harm. It means that the available evidence is insufficient to assume safety in these circumstances, and potential risks may outweigh uncertain benefits. A careful decision takes account of medical history, current treatment, pregnancy or breastfeeding status, and the purpose of supplementation.

What Medication Interactions Matter?

Ashwagandha may interact with medications used for thyroid disorders, diabetes, high blood pressure, seizures, and immune suppression. It may also interact with sedatives. The significance of these interactions can vary, and evidence is not equally strong for every combination, but the possibility is important enough to warrant professional review before use.

For example, someone taking thyroid hormone medication may need particular caution because ashwagandha has been associated with changes in thyroid-related measurements. A person using sedating medication may be more vulnerable to drowsiness when adding another substance that can cause sedation. Other medication combinations may require consideration of blood glucose, blood pressure, or immune function.

Multi-ingredient supplements make this assessment more complicated. It is not enough to consider ashwagandha in isolation if a product also contains minerals, amino acids, or other botanicals. The complete ingredient list and the amounts taken each day should be reviewed, especially when several supplements are used together.

Before starting a supplement, consumers should tell their healthcare professional or pharmacist about prescription medications, over-the-counter products, and other supplements they use. This helps identify possible interactions and determine whether additional monitoring is appropriate. People should not stop prescribed treatment, change a medication dose, or use ashwagandha to manage a diagnosed condition without medical guidance.

Evidence about cortisol-related outcomes does not establish that the ingredient can replace appropriate care. A responsible decision considers both the potential benefits and the uncertainties around interactions and long-term use.

What Should Consumers Check on Labels?

A clear supplement label makes it easier to understand what a product contains and whether the available research is relevant. Start by checking the botanical name, plant part, extract amount per serving, and any stated standardization. These details help distinguish raw plant material from concentrated extracts and provide a starting point for comparing products. The front-label ingredient name alone is not enough to establish equivalence to a preparation used in a clinical trial.

Next, review the full Supplement Facts panel, other ingredients, serving directions, warnings, and number of servings per container. If the product combines multiple ingredients, the amounts of each active component matter. Quality documentation can provide further information about ingredient identity, specifications, contaminants, and batch consistency. A certificate of analysis may support certain quality claims, but it does not independently prove that a product will produce a specific health outcome.

Consumers should also distinguish research about an ingredient from research about a finished product. If a trial studied a particular extract in a selected population for eight weeks, that result does not automatically support the same claim for a different dose, delivery format, or multi-ingredient formula. A branded ingredient does not establish that the finished supplement has been clinically tested for every advertised outcome.

When comparing products, check the exact ingredient amounts, extract specifications, relevant quality information, directions, and warnings. If important details are missing or cannot be verified, it becomes harder to assess how closely the formulation matches published research. Transparent labeling and realistic claims provide a stronger basis for a decision than broad promises about lowering cortisol.

Conclusion

Ashwagandha cortisol research offers a useful example of how nutrition science can be encouraging without being conclusive. Randomized controlled trials have reported meaningful differences in cortisol concentrations, including results that were statistically significant compared with placebo. Recent systematic reviews provide additional support for an overall cortisol effect while highlighting differences between studies and the gap between hormone measurements and the stress people experience in everyday life.

For consumers, the most important conclusion is that ashwagandha has been studied for cortisol-related outcomes, but the research does not establish a universal result for every person, extract, or supplement formula. Choosing an appropriate product requires more than recognizing a familiar ingredient or comparing the largest percentage reported in a clinical trial. Ingredient identity, serving amount, study quality, potential interactions, and realistic expectations all deserve attention.

A thoughtful approach to wellness also recognizes that cortisol is a normal hormone, not a number that should always be pushed lower. Consistent sleep habits, balanced nutrition, physical activity, and appropriate professional support remain important parts of overall well-being. When considering a supplement, consumers benefit most from clear formulation information, evidence that matches the actual product, and honest communication about both the findings and their limitations.

Frequently Asked Questions

1. Does ashwagandha lower cortisol according to clinical trials?

Several randomized controlled trials have reported lower cortisol levels with specific ashwagandha extracts compared with placebo. However, results vary by preparation, population, and study method. These findings do not establish that every supplement will lower cortisol or that all users will experience the same response.

2. How long did ashwagandha cortisol studies last?

Frequently cited trials lasted approximately six to eight weeks, including a 60-day study published in 2012 and an eight-week trial published in 2019. These durations describe the research protocols rather than a guaranteed timeline for results. Longer-term effects and safety remain less well established.

3. What dose of ashwagandha was used in cortisol RCTs?

Examples include 600 mg per day of a specific root extract in the 2012 trial and 250 mg or 600 mg per day in the 2019 study. These are study-specific amounts, not personalized recommendations. Extract composition and standardization matter, so the milligram amount alone does not establish equivalence between products.

4. Does lower cortisol mean ashwagandha reduces perceived stress?

Not necessarily. Cortisol is a biological marker, whereas perceived stress is usually assessed through questionnaires about a person's experience. A 2025 meta-analysis found a statistically significant pooled cortisol reduction but no statistically significant overall improvement in perceived stress scores. The two outcomes should therefore be considered separately.

5. Is ashwagandha safe for daily use?

Safety depends on the preparation, duration, and individual circumstances. Ashwagandha may cause digestive upset or drowsiness, and rare cases of liver injury have been reported. Long-term safety remains uncertain. Pregnancy, breastfeeding, thyroid or autoimmune disorders, upcoming surgery, certain cancers, and medication use warrant particular caution or avoidance.

6. Can an ashwagandha supplement claim to lower cortisol because its ingredient was studied?

Ingredient-level research does not automatically establish the effectiveness of a finished supplement. The formulation, ingredient amount, extract specifications, and study population may differ from those in the published trial. Product claims should be supported by appropriate evidence and reviewed for applicable regulatory requirements rather than inferred solely from the presence of ashwagandha.