Categories & Effectiveness

Cognition

Working & Long-term Memory

4/10

Moderate evidence of effectiveness

Mood

Anxiety / Stress Reduction

7/10

Strong evidence of effectiveness

Relaxation / Sleep Preparation

7/10

Strong evidence of effectiveness

Mood Enhancement / Antidepressant Effect

4/10

Moderate evidence of effectiveness

Dosage & Side Effects

Recommended Dosage

The typical daily dosage for Ashwagandha extract ranges from 120 mg to 1000 mg, often split into two doses, though dried root powder has been used up to 12 grams daily in some studies. Effectiveness can be dose-dependent, with studies suggesting higher doses (e.g., 600mg daily) may be more effective for certain outcomes like anxiety and sleep than lower doses, while optimal effects might require consistent use for 8 weeks or more. Dosing may vary based on the specific extract standardization (e.g., KSM-66, Sensoril, Shoden) and individual needs; consult product labels and consider starting low.

Potential Side Effects

Ashwagandha is generally well-tolerated, with most studies reporting mild and transient side effects comparable to placebo, such as drowsiness or mild gastrointestinal upset. Although rare, there have been cases of reversible liver injury associated with Ashwagandha use, particularly with higher doses (450-1350mg daily) or prolonged use, highlighting the need for more safety research. Individuals with liver conditions, autoimmune diseases, thyroid disorders, or those who are pregnant or breastfeeding should exercise caution or avoid use; potential interactions with sedatives, thyroid medication, and immunosuppressants warrant discussion with a healthcare provider.

Interactions & Stacks

Ashwagandha is often used alone but may complement other adaptogens or calming nootropics; however, specific synergistic stacks lack extensive research. Caution is advised when combining Ashwagandha with sedatives (like benzodiazepines or alcohol), thyroid medications, immunosuppressants, or certain antidepressants, as animal studies suggest potential potentiation or additive effects, though human interaction data is limited. User reports often highlight its calming effects, but always consult a healthcare professional before combining supplements or medications.

Benefits by Use Case

Stress Reduction

Helps lower perceived stress levels and serum cortisol. Consistent daily use for several weeks is typically needed for significant effects.

Anxiety Relief

May reduce symptoms of anxiety, particularly generalized anxiety, as shown by improvements in scales like HAM-A. Higher doses (e.g., 600mg/day) might be more effective than lower doses.

Improved Sleep Quality

Can enhance sleep quality, reduce time to fall asleep (SOL), and decrease nighttime awakenings (WASO), especially in those with insomnia. Benefits often seen after several weeks of use, potentially more pronounced at doses ≥600mg/day.

Cognitive Support

Shows potential for improving aspects of cognitive function, including memory and attention. Research is ongoing, and effects may be linked to stress reduction.

Enhanced Sports Performance

May improve strength, power output, VO2max, and recovery in athletic individuals. Effects observed across various dosages (120-1250mg/day) over 2-12 weeks.

Mechanism of Action

Ashwagandha exerts its effects through multiple pathways, reflecting its adaptogenic nature. It modulates the body's stress response by influencing the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic-adrenal-medullary (SAM) axis, often leading to reduced cortisol levels. Its anxiolytic and sleep-promoting effects are linked to interactions with the GABAergic system, potentially acting as a GABAA receptor agonist or positive allosteric modulator, enhancing inhibitory neurotransmission. Additionally, Ashwagandha may influence serotonergic pathways, possess antioxidant properties that protect against oxidative stress, and exhibit anti-inflammatory actions by reducing pro-inflammatory cytokines (like IL-6 and TNF-α) and modulating immune responses. Specific compounds like withanolides (including withaferin A and withanosides) and sitoindosides are believed to contribute significantly to these activities, though the full spectrum of active components is still under investigation.

Frequently Asked Questions

Is Ashwagandha safe to take daily?

When is the best time to take Ashwagandha?

How long does it take for Ashwagandha to work?

Can Ashwagandha help with anxiety?

Does Ashwagandha increase testosterone?

Will Ashwagandha make me drowsy?

Can I take Ashwagandha with antidepressants?

Which Ashwagandha extract is best?

Summary & Expert Opinion

Ashwagandha is a well-researched adaptogen with substantial evidence supporting its use for reducing stress, anxiety, and improving sleep quality. Its key strengths lie in its multi-target mechanisms, addressing stress via the HPA axis and GABAergic pathways, but limitations include variability between extracts and potential bias in some older studies. Individuals experiencing significant stress, anxiety, or sleep disturbances may find Ashwagandha particularly beneficial, often requiring several weeks of consistent use. Those with thyroid conditions, autoimmune diseases, liver problems, or who are pregnant/breastfeeding, as well as individuals taking sedatives, thyroid medication, or immunosuppressants, should avoid Ashwagandha or consult a healthcare professional before use due to potential interactions and rare safety concerns.

Research Studies

Showing 5 of 7 studies

Withania somnifera (Ashwagandha) supplementation: a review of its mechanisms, health benefits, and role in sports performance (2025)

antioxidant anxiety reduction cognitive function +6 more

Authors:

Mateusz Sprengel, Radosław Laskowski, Zbigniew Jost

Findings:

This review summarizes evidence suggesting Ashwagandha supplementation aids sleep (especially in insomniacs), reduces stress (lowering cortisol and perceived stress), enhances sports performance (improving strength, power, VO2max, recovery), increases testosterone, improves male fertility, reduces anxiety, and benefits cognitive functions (memory, attention, executive function). Potential mechanisms involve GABAergic activity, HPA axis modulation, antioxidant/anti-inflammatory effects, and hormonal changes. While generally safe with mild, transient side effects reported (similar to placebo), rare cases of reversible liver injury have occurred, necessitating further safety research, especially for high doses and long durations.

Participants:

The review covers studies involving various populations: healthy adults, stressed adults, adults with insomnia, adults with Generalized Anxiety Disorder, adults with fertility issues, young adults (17-45 years, mixed sexes, various fitness levels), elderly individuals, aged overweight males, college students, athletes (hockey players, elite cyclists), children. Specific participant numbers mentioned include N=400 (sleep meta-analysis), N=142 (VO2max meta-analysis), N=615 (sports performance review). Animal (rodent) and cell (glioblastoma, neuroblastoma, muscle) models were also discussed for mechanistic insights.

Dosage:

Dosages varied by study: Sleep (≥600mg/d more effective than <600mg/d, ≥8 weeks better than <8 weeks); Stress (250-500mg daily for 4-13 weeks); VO2max (330-1000mg/d for 2-12 weeks); Sports performance review (120-1250mg daily for 2-12 weeks); Anxiety (125-1000mg/d); Acute cognition (single 400mg dose); Safety studies (300-600mg daily for 8-12 weeks); Liver injury cases (associated with 450-1350mg daily).

Study Quality Assessment:

This document is a narrative review citing systematic reviews, meta-analyses, and randomized controlled trials (RCTs), many of which were double-blind and placebo-controlled. Methodologies mentioned include specific scales (Sleep Quality Scale, Perceived Stress Scale, Hamilton Anxiety Scale, etc.), physiological measures (cortisol, VO2max, strength tests), and biochemical markers. Acknowledged limitations include the paucity of data in certain areas (mechanisms, physical performance, especially in trained athletes), small numbers of studies and heterogeneity in some meta-analyses, potential high risk of bias in early anxiety studies, limited human data on metabolic health and cognition in aging, need for higher quality sleep measurement methods (polysomnography vs. actigraphy), and insufficient data on long-term/high-dose safety. The funding source is mentioned (National Ministry of Science Grant).

All Effects:

antioxidant anxiety reduction cognitive function fertility safety sleep quality sports performance stress reduction testosterone

Effects of Withania somnifera (Ashwagandha) on Stress and the Stress-Related Neuropsychiatric Disorders Anxiety, Depression, and Insomnia (2021)

anxiety reduction depression insomnia +2 more

Authors:

Alex B Speers

Findings:

Withania somnifera (WS) root and leaf extracts demonstrated noteworthy anti-stress and anti-anxiety activity in both animal and human studies reviewed. WS also showed potential benefits for improving symptoms of depression and insomnia, although fewer studies investigated these applications. Proposed mechanisms involve modulation of the HPA and SAM axes, as well as GABAergic and serotonergic pathways.

Participants:

Human trials involved adults aged 18-85 years (N ranged from 39 to 150), including healthy individuals, those experiencing stress, anxiety (including GAD), insomnia, non-restorative sleep, overweight/obesity with chronic stress, or schizophrenia/schizoaffective disorder. Animal studies involved rats, mice, and horses.

Dosage:

Human trials used daily doses ranging from 120 mg to 1000 mg of various extracts (KSM-66, Sensoril, Shoden, ethanolic extracts) administered once or twice daily, and up to 12 g daily of dried root granules. Animal studies used various doses, often specified in mg/kg body weight (e.g., 10-500 mg/kg p.o. or i.p.) or g/day (horses). Specific standardizations mentioned include >5% withanolides, 5% withanolides, ≥8% withanolide glycosides, 11.90% withanolide glycosides, 35% withanolide glycosides.

Study Quality Assessment:

Review of preclinical (animal) and clinical (human) studies. Human trials described included randomized, double-blind, placebo-controlled designs. Methods mentioned include various behavioral questionnaires (e.g., PSS, HAM-A, DASS, PSQI, GHQ-28, PANSS, RSQ-W, sleep quality ratings), objective sleep actigraphy, and biological markers (e.g., serum cortisol, hsCRP, DHEA-S, testosterone, IL-6, S100B). Sample sizes in human trials ranged from N=39 to N=150. Limitations acknowledged include significant variability in WS extracts tested, lack of consensus on optimum preparation/dosage, need for further elucidation of active compounds, and need for herb-drug interaction studies. Conflicts of interest were declared as none.

All Effects:

anxiety reduction depression insomnia sleep quality stress reduction

A randomized, double blind, placebo controlled study to evaluate the effects of ashwagandha (Withania somnifera) extract on sleep quality in healthy adults (2020)

Authors:

Abhijit Deshpande, Irin Rosanna Benny, Nushafreen Irani, Ratna Balkrishnan

Participants:

healthy adults

Study Quality Assessment:

randomized, double blind, placebo controlled study

An alternative treatment for anxiety: a systematic review of human trial results reported for the Ayurvedic herb ashwagandha (Withania somnifera)

anxiety reduction placebo comparison stress reduction +1 more

Findings:

Five human trials met inclusion criteria. Three studies compared Ashwagandha (WS) extract dosages to placebo using anxiety scales (two showed significant benefit, one approached significance). Another study found naturopathic care with WS reduced BAI scores more than psychotherapy (56.5% vs 30.5%, p<0.0001). A fifth study found WS reduced PSS scores more than placebo (44.0% vs 5.5%, p<0.0001). All five studies concluded WS resulted in greater improvements on anxiety/stress scales than placebo, but evidence should be viewed cautiously due to methodological issues and potential bias.

Participants:

Human trials participants (details not specified in abstract)

Dosage:

Three studies compared 'several dosage levels of WS extract' with placebos, but specific dosages are not detailed in the abstract.

Study Quality Assessment:

Systematic review of human randomized controlled trials. Searches conducted in PubMed, SCOPUS, CINAHL, Google Scholar, reference lists, and AYUSH Research Portal. Inclusion criteria applied during abstract screening. Outcome measures included Hamilton Anxiety Scale, Beck Anxiety Inventory (BAI), Perceived Stress Scale (PSS). Limitations: All included studies exhibited unclear or high risk of bias; heterogenous design and reporting prevented meta-analysis.

All Effects:

anxiety reduction placebo comparison stress reduction systematic review

An investigation into the stress-relieving and pharmacological actions of an ashwagandha (Withania somnifera) extract: A randomized, double-blind, placebo-controlled study

Participants:

N=60 stressed, healthy adults

Dosage:

240 mg of a standardized ashwagandha extract (Shoden) once daily

Study Quality Assessment:

60-day, randomized, double-blind, placebo-controlled study, N=60

Effects of Acute Ashwagandha Ingestion on Cognitive Function

cognitive function memory mood +1 more

Findings:

The study aims to determine if acute ashwagandha supplementation affects memory and cognitive function, noting that prior reports suggest it may decrease stress, enhance mood, and improve cognition.

Dosage:

acute supplementation (dose not specified)

All Effects:

cognitive function memory mood stress

Efficacy and Safety of Ashwagandha (Withania somnifera (L.) Dunal) Root Extract in Improving Memory and Cognitive Functions

cortisol reduction memory psychological well-being +2 more

Findings:

Ashwagandha SR significantly improved recall memory and reduced errors in pattern recall (CANTAB), significantly reduced perceived stress (PSS-10) and serum cortisol levels, significantly improved sleep quality (PSQI), and significantly enhanced psychological well-being (OHQ) compared to placebo over 90 days. No adverse events were reported.

Participants:

130 healthy, cognitively sound, stressed adults (age 20-55 years, BMI 18-29 kg/m2, Perceived Stress Scale [PSS] score 14-24).

Dosage:

One 300mg sustained-release (SR) capsule (Prolanza™) daily for 90 consecutive days.

Study Quality Assessment:

Randomized, double-blind, placebo-controlled clinical study; N=130 randomized (125 completed); Duration: 90 days; Primary endpoint measured by Cambridge Neuropsychological Test Automated Battery (CANTAB); Secondary outcomes: PSS-10, serum cortisol, Oxford Happiness Questionnaire (OHQ), Pittsburgh Sleep Quality Index (PSQI), serum BDNF; Registered on Clinical Trials Registry-India (CTRI/2019/11/021990); Ethics committee approved; Conducted per Good Clinical Practice/Declaration of Helsinki; Funded by Inventia Healthcare Ltd. and Laila Nutraceuticals; Limitation acknowledged: need for larger, longer studies.

All Effects:

cortisol reduction memory psychological well-being sleep quality stress reduction

We value your privacy

Categories & Effectiveness

Cognition

Working & Long-term Memory

Mood

Anxiety / Stress Reduction

Relaxation / Sleep Preparation

Mood Enhancement / Antidepressant Effect

Dosage & Side Effects

Recommended Dosage

Potential Side Effects

Interactions & Stacks

Benefits by Use Case

Stress Reduction

Anxiety Relief

Improved Sleep Quality

Cognitive Support

Enhanced Sports Performance

Mechanism of Action

Frequently Asked Questions

Summary & Expert Opinion

Research Studies

Withania somnifera (Ashwagandha) supplementation: a review of its mechanisms, health benefits, and role in sports performance (2025)

Authors:

Findings:

Participants:

Dosage:

Study Quality Assessment:

All Effects:

Effects of Withania somnifera (Ashwagandha) on Stress and the Stress-Related Neuropsychiatric Disorders Anxiety, Depression, and Insomnia (2021)

Authors:

Findings:

Participants:

Dosage:

Study Quality Assessment:

All Effects:

A randomized, double blind, placebo controlled study to evaluate the effects of ashwagandha (Withania somnifera) extract on sleep quality in healthy adults (2020)

Authors:

Participants:

Study Quality Assessment:

An alternative treatment for anxiety: a systematic review of human trial results reported for the Ayurvedic herb ashwagandha (Withania somnifera)

Findings:

Participants:

Dosage:

Study Quality Assessment:

All Effects:

An investigation into the stress-relieving and pharmacological actions of an ashwagandha (Withania somnifera) extract: A randomized, double-blind, placebo-controlled study

Participants:

Dosage:

Study Quality Assessment:

Effects of Acute Ashwagandha Ingestion on Cognitive Function

Findings:

Dosage:

All Effects:

Efficacy and Safety of Ashwagandha (Withania somnifera (L.) Dunal) Root Extract in Improving Memory and Cognitive Functions

Findings:

Participants:

Dosage:

Study Quality Assessment:

All Effects:

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