Ashwagandha.
May help manage stress and support healthy testosterone levels. Helps your body manage stress by lowering cortisol. Think of it as turning down the volume on your body's stress response.
Reviewed July 2026
- Category
- Herb
- Also filed under
- Stress reductionMay support healthy testosterone levelsImproved sleep quality
- Also called
- Withania Somnifera, Ashwagandha Root, Ashwagandha Root Powder Extract, Ashwagandha Extract
What Ashwagandha is, and what it does.
- Does it work
- Yes. It's a solid, well-studied adaptogen for stress. If you're constantly wired, it's worth a shot. Testosterone benefits are a possible bonus, not the main event.
- How much to take
- Start with 300 to 500mg a day of a root extract carrying a stated withanolide percentage. That band is where daily use sits. 1,200mg shows up in trials as a research condition.
- Time to feel it
- About eight to nine weeks of daily use.
- The first dose
- Probably nothing. It needs to build up in your system over a few weeks.
- With regular use
- After 2-4 weeks, a noticeable drop in general anxiety. Better sleep. You feel more resilient to stress, not numb to it.
- How well tolerated
- Generally well tolerated for most people. The main watch-outs are for thyroid and autoimmune conditions. Don't take it if you're pregnant.
- How it feels
- Calming, not sedating. It's the feeling of having a bit more bandwidth to deal with life. Less snapping at people in traffic.
- The overlooked benefit
- The trials that measured sleep rather than stress found people settled faster and rated their nights better, so it earns a place in an evening routine as much as a morning one.
300 to 500mg a day is where Ashwagandha works.
Source: Chandrasekhar 2012 + Lopresti 2019 meta-analysis
What the trial measured, in its words
In a 60 day randomised, double-blind, placebo-controlled trial, 60 stressed healthy adults took 240 mg of a standardised ashwagandha extract (Shoden) once daily or placebo. The ashwagandha arm showed a larger fall in Hamilton Anxiety Rating Scale scores (p = .040) and in morning cortisol (p < .001) than placebo, with the DASS-21 change near-significant (p = .096). A separate 8 week randomised, double-blind, placebo-controlled dose-ranging trial enrolled 131 adults with self-reported high stress and analysed 98, measuring reduced Perceived Stress Scale scores at 125, 250 and 500 mg per day of an aqueous root and leaf extract. Two trials on two different extracts, both landing in the same eight to nine week band.
The proof, claim by claim.
What these words mean
These words describe the research, not the molecule's worth. Research strength is how much work stands behind one claim, and it is never a product score.
There's a good body of evidence supporting ashwagandha's stress-reducing effects. The evidence for testosterone support is promising but requires further investigation, particularly comparing it to other readily available supplements.
- Perceived stress and serum cortisol, a marker of the stress axisMeta-analysis
- Sleep quality and time taken to fall asleepMeta-analysis
5 more claims
- Testosterone already in the normal range in menRandomised trial
- Strength and lean mass alongside resistance trainingRandomised trial
- Endurance capacity measured as peak oxygen uptakeMeta-analysis
- Memory and attention scores in healthy adultsRandomised trial
- Sexual wellbeing and reported driveRandomised trial
Questions people ask about Ashwagandha.
- Will it make me sleepy during the day?
- Shouldn't. It's calming, not a sedative. Most people take it anytime without issues.
5 more questions
- Can I take it forever?
- You can, but some people like to cycle it. Try 8-12 weeks on, then a few weeks off to give your body a reset.
- What's KSM-66?
- Just a brand name for a well-studied extract. It's a good sign of quality on the label. Sensoril is another one.
- Will it actually boost my testosterone?
- Maybe. Some studies show a modest bump, especially in men with lower levels. But don't expect steroid-like results. That's not how biology works.
- Can I take this with my antidepressant?
- Talk to your doctor. Seriously. It can interact with meds that affect your brain chemistry.
- Does it taste bad?
- Yes, the powder is notoriously bitter. That's why most people use capsules.
Why these belong in the same formula, 30 pairings
Why these belong in the same formula. Each row says what the basis is, from settled biochemistry through to a trial that measured the pair.
Ashwagandha supports a calmer stress response, and magnesium is an essential mineral cofactor for the nerve signaling and muscle function that let the body settle. The two are long paired in evening and stress support blends because they support the same settling physiology by different routes.
L-theanine shifts brain activity toward relaxed alpha wave patterns and supports a calm but alert state, reaching it by a different route than ashwagandha's action on the stress response axis. That complementary pairing is why the two are routinely combined in calm focus formulas.
Both are long used adaptogens that act on the HPA stress response system, with ashwagandha leaning calming and rhodiola leaning more activating and energizing. Formulators pair them so a blend supports steadiness under everyday stress without landing too sedating or too stimulating.
Withanolides act on GABA-A signalling while glycine works at its own inhibitory receptor and lowers core body temperature at night. The two reach settled sleep onset by different routes, which is why they share evening formulas.
Phosphatidylserine acts on feedback sensitivity of the hypothalamic pituitary adrenal axis while ashwagandha lowers cortisol output at the adrenal end. Pairing them addresses the same normal stress response at two points.
Piperine slows intestinal glucuronidation and some CYP-mediated clearance, which raises exposure to a range of lipophilic plant actives. Ayurvedic practice paired pepper with root extracts long before the enzymology was described.
Valerenic acid and the withanolides both act as positive modulators at GABA-A sites, so their calming effects stack. That is useful in an evening formula and worth knowing about for daytime dosing.
Passionflower flavonoids act at benzodiazepine-sensitive GABA-A sites, overlapping the withanolide mechanism. The combined evening effect is likely stronger than either alone.
Ashwagandha raises circulating T4 and T3 within the normal range, and iodine is the substrate the gland needs to make them. Stacking both pushes the same output in one direction, so the pairing warrants attention rather than casual combination.
The deiodinase enzymes that convert T4 to T3 are selenoproteins, so selenium status governs the step ashwagandha nudges. The effect on normal thyroid hormone levels runs in the same direction.
Caffeine blocks adenosine receptors to raise arousal while withanolides lower sympathetic tone, so the pair smooths the jittery edge of a stimulant without cancelling the alertness. This is why ashwagandha appears in stimulant preworkout and focus blends.
Melatonin acts on circadian timing through MT1 and MT2 receptors while ashwagandha lowers evening cortisol and leans on GABA-A signalling. One sets the clock, the other lowers arousal, so evening formulas pair them.
Withanolides are lipophilic steroidal lactones with limited water solubility, and a lipid vehicle helps disperse them for uptake. Oil-based and lipid-loaded ashwagandha presentations rest on this.
Panax ginseng and ashwagandha occupy the same adaptogen category and appear together in stress and stamina formulas. Their characterised constituents differ, ginsenosides against withanolides, so the pairing is compositional rather than mechanistic. No combination trial is cited here.
Eleuthero is a long-standing member of the same adaptogen grouping and is blended with ashwagandha in stress-support products. The rationale is traditional and formulary. Read it as convention, not as demonstrated additivity.
Schisandra lignans and ashwagandha withanolides are combined in classical adaptogen blends aimed at the stress response. The two constituent classes are chemically unrelated and have not been tested together in the evidence supplied here. This is a formulation pairing.
Cordyceps is paired with ashwagandha in stamina and training-support formulas, where each is included for its own reasons rather than for an interaction. No shared pathway is established between a fungal preparation and a withanolide-standardised root extract. The pairing is formulation practice.
Bacopa and ashwagandha are the two most commonly combined Ayurvedic botanicals in cognitive-support blends, and each has its own human literature on cognitive measures. Their active constituent classes differ, bacosides against withanolides. Nothing in the sources supplied tests the combination.
Lion's mane appears alongside ashwagandha in cognitive and stress blends sold as a single product. The two act through unrelated chemistry and have separate literatures. Count the pairing as category convention.
Tyrosine is the amino acid precursor for dopamine and noradrenaline, and it is combined with ashwagandha in products aimed at performance under stress. The precursor role is established biochemistry. The combined effect is not tested in the sources here. The two work on different levels of the same broad system.
Withanolide preparations have been described in preclinical work as acting at GABA-A receptor sites, and supplemental gamma-aminobutyric acid is taken for the same calming intent. Stacking two agents pointed at the same receptor system is worth flagging for additive drowsiness. The receptor work is preclinical.
Chamomile apigenin binds benzodiazepine sites on the GABA-A receptor, the same receptor family implicated in preclinical work on withanolides. Combined use can add to daytime drowsiness even when each alone is mild. Flag the direction rather than assume a benefit.
Lemon balm constituents inhibit GABA transaminase, raising local gamma-aminobutyric acid availability, and ashwagandha is used for the same calming purpose. The combination is common in evening formulas. The interaction to watch is additive sedation.
Honokiol and magnolol are described as positive modulators at GABA-A receptors, which is the same site preclinical ashwagandha work points to. Sleep and stress blends frequently carry both. Additive drowsiness is the practical consequence.
5-hydroxytryptophan is the immediate precursor to serotonin and then melatonin, and it is combined with ashwagandha in evening mood and sleep products. The precursor step is established. The combination is not tested in the sources here. Two calming agents together can add up.
Ashwagandha has been tested for strength, endurance and recovery measures in trained and amateur athletes, which is the same category creatine occupies. The two act through entirely separate mechanisms, one phosphagen and one endocrine and stress-axis. Co-formulation is convention, not a measured interaction.
Turmeric and ashwagandha are classical Ayurvedic companions and are frequently sold in the same formula. Both are lipophilic preparations that are commonly taken with food containing fat. The pairing is traditional and formulary rather than demonstrated.
Both botanicals appear in products aimed at hormonal balance and training response in men, each with its own small human literature. No supplied source tests them together. Stacking two agents pointed at the same axis is a reason to read labels rather than a demonstrated gain.
KSM-66 is a branded root extract standardised to a declared withanolide percentage, so taking it alongside another ashwagandha preparation stacks the same constituent class rather than adding a second one. The practical point is total withanolide intake across the whole stack. Check both labels before combining.
Ascorbic acid is added to botanical stress formulas as an antioxidant and as a stabiliser for the finished blend. Its own role in normal adrenal tissue is established biochemistry, but nothing supplied tests it with ashwagandha. The pairing is formulation practice.
Talk to a doctor before taking Ashwagandha if any of these apply to you: Pregnancy, Thyroid disorders, Autoimmune diseases. These are flags to check first, not effects Ashwagandha is known to cause.
Not medical advice. Show the label to your pharmacist.What Ashwagandha actually does.
The constituents that have been characterised in ashwagandha are withanolides, a family of steroid-like compounds including withaferin A and withanolide A. Extracts are standardised to a stated withanolide percentage.
3 more mechanisms
Root and leaf carry different withanolide mixes, with withaferin A more concentrated in the leaf. So which plant part was used is part of what an extract actually is.
Withanolides are fat-loving steroid-like molecules, so the solvent used during extraction decides which compounds carry through into the finished powder.
The root also holds alkaloids and saponins alongside the withanolides. So a water extract and an alcohol-water extract of the same root aren't chemically interchangeable.
Where Ashwagandha comes from.
The roots are dug up, dried and ground, then soaked in water or in an alcohol and water mix to pull out the compounds called withanolides. That liquid is concentrated and dried back into a powder, and each batch is tested so the label can state a withanolide percentage. Plain ground root is also sold, and it is far less concentrated than an extract, so the two are not swappable gram for gram.
What this route gives you
Made from a plant. What ends up in the capsule tracks the harvest, so batch testing and a stated marker matter more here than with a made molecule.
6 steps on record
The plant is grown as an annual, mainly in India, and the roots are lifted after the growing season. Root diameter and age at harvest affect the constituent profile.
Roots are washed, cut to length and dried to a low moisture content, then milled to a coarse powder before extraction.
The milled root is percolated or macerated with water, or with an ethanol and water mixture, which changes how much of the lipophilic withanolide fraction is recovered.
The liquid extract is filtered to remove plant solids, then concentrated under vacuum at reduced temperature to limit heat exposure of the withanolides.
The concentrate is assayed by HPLC and blended with a carrier such as maltodextrin or with lower-strength material to hit a declared withanolide percentage.
The standardised concentrate is spray-dried to a free-flowing powder, then encapsulated, tableted or blended into a stick pack.
Some labels state only ashwagandha extract without naming the plant part or the extraction solvent, both of which change what is in the capsule.
The forms it comes in.
5 more forms
The essence, in one line each.
- Pooling nine randomized trials in 558 patients, ashwagandha lowered perceived stress scores by about 4.7 points and serum cortisol levels by about 2.6 units compared with placebo.Meta-analysis. Arumugam et al., 2024 (Explore). PMID 39348746 ↗
20 more findings
- Across five randomized trials in 400 adults, ashwagandha extract improved overall sleep with a small pooled effect (standardized mean difference -0.59), an effect the authors noted was more prominent in adults with diagnosed sleep difficulty, at doses of 600 mg or more per day, and for eight weeks or longer.Meta-analysis. Cheah et al., 2021 (PLoS One). PMID 34559859 ↗
- Pooling four randomized trials in 142 athletes and healthy adults, ashwagandha raised maximal oxygen uptake (VO2max) by about 3.0 mL/kg/min compared with placebo.Meta-analysis. Perez-Gomez et al., 2020 (Nutrients). PMID 32316411 ↗
- Pooling randomised trials, ashwagandha supplementation lowered self-reported anxiety and stress scores compared with placebo.Meta-analysis. Akhgarjand et al., 2022 (Phytotherapy research). PMID 36017529 ↗
- In a meta-analysis of trials in mainly young adults and athletes, ashwagandha supplementation was associated with improved exercise performance, with the most consistent evidence for aerobic endurance.Meta-analysis. Li et al., 2026 (Nutrients). PMID 42356302 ↗
- Pooling randomised trials, Withania somnifera was associated with shifts in circulating hormone levels, including testosterone and cortisol.Meta-analysis. Fornalik et al., 2026 (Planta medica). PMID 41740946 ↗
- Both single-dose and repeated ashwagandha supplementation improved measures of cognitive performance and self-reported mood in younger healthy adults.Randomised trial. Leonard et al., 2024 (Nutrients). PMID 38931168 ↗
- In healthy men, ashwagandha root extract was associated with improved self-reported sexual function scores over the study period.Randomised trial. Khanna et al., 2026 (Frontiers in reproductive health). PMID 41766918 ↗
- In young healthy men, adding ashwagandha to an 8-week high-intensity interval training program showed no detectable extra change in body composition, lipid profile, or hormones related to energy metabolism.Randomised trial. Charmas et al., 2025 (Nutrients). PMID 41156498 ↗
- A meta-analysis of 20 trials in adults found that ashwagandha improved several aspects of cognitive function, muscle strength, and testosterone levels, with no detectable effect on body weight or body fat.Systematic review. Zhu et al., 2026 (Frontiers in Pharmacology). PMID 42199854 ↗
- A dose-response meta-analysis of ashwagandha on mental wellbeing measures in adults, reporting how the pooled effect tracks with dose.Meta-analysis. Alsanie et al., 2026 (Complementary Therapies in Medicine). PMID 41644067 ↗
- Ashwagandha root extract was associated with steadier physiological stress response measures across a competitive period in male and female team sport athletes.Randomised trial. Coope et al., 2026 (Nutrients). PMID 41599843 ↗
- A clinical assessment of ashwagandha root extract reporting changes in cognitive performance, sleep and fatigue measures over the study period.Randomised trial. Saxena et al., 2026 (Frontiers in Nutrition). PMID 41889719 ↗
- In a 60-day randomized trial in 126 healthy adults with stress, taking 150 mg or 300 mg of a sustained-release ashwagandha root extract daily significantly reduced perceived stress and improved sleep quality, eating behavior, and psychological well-being compared to a placebo.Randomised trial. Thanawala et al., 2026 (Medicine). PMID 41824889 ↗
- A low-dose ashwagandha regimen was compared with placebo on exercise endurance measures.Randomised trial. Prajapati et al., 2026 (Phytotherapy Research). PMID 41846233 ↗
- In a trial with male handball players, taking 600 mg of ashwagandha daily for 8 days improved handgrip strength compared to a placebo, but did not meaningfully change lower-limb strength, perceived soreness, fatigue, or recovery.Randomised trial. Ferreira et al., 2026 (Nutrition and Health). PMID 41940566 ↗
- In healthy men doing 8 weeks of high-intensity interval training, ashwagandha did not appear to offer additional benefits for aerobic capacity beyond the effects of the training itself.Randomised trial. Ewa et al., 2025 (Biology of Sport). PMID 40657001 ↗
- A prospective study recording tolerability of ashwagandha root extract in healthy adults over the supplementation period.Open-label trial. Movva et al., 2026 (Frontiers in Nutrition). PMID 42253745 ↗
- One adult developed acute involuntary muscle contractions after taking ashwagandha. A single case report describes a temporal sequence and cannot establish cause.Case report. Fazlani et al., 2025 (Cureus). PMID 40896056 ↗
- In a review of five human trials in people with anxiety or stress, ashwagandha led to greater improvements on anxiety and stress scales than a placebo, with the difference being significant in most cases.Systematic review, in people with anxiety or stress. Pratte et al., 2014 (Journal of alternative and complementary medicine). PMID 25405876 ↗
- In a meta-analysis of five trials in 254 adults with diagnosed anxiety or sleep difficulty, ashwagandha was linked to better self-reported sleep quality.Meta-analysis, in patients with anxiety and/or insomnia. Fatima et al., 2024 (Human psychopharmacology). PMID 39083548 ↗
Chosen from the 2,244 we read for Ashwagandha.
The studies, linked.
7 sources behind our Ashwagandha verdict, every one linked to PubMed, the journal or ClinicalTrials.gov.
- Clinical trialEffects on Sleep Quality and Bioelectrical Parameters of Cellular Health After Administration of a Plant Protein Supplement Combined With Ashwagandha and RhodiolaClinicalTrials.gov ↗100 participants, Completed
6 more linked trials
- Clinical trialThe Impact of Ashwagandha on Stress, Sleep and Food Cravings in College Students: A Mixed Method Double-blinded Randomized Control TrialClinicalTrials.gov ↗Phase 2, 60 participants, Completed
- Clinical trialEffects of Daily Intake of Ashwagandha (Withania Somnifera) Root Extract Sustained Release (SR) Capsules 150mg on Disturbed Sleep: a Phase II, Randomized Placebo-controlled Trial With Wearable DeviceClinicalTrials.gov ↗54 participants, Completed
- Clinical trialEfficacy and Safety of Shatavari in Women Sexual Wellness: A Prospective, Randomized, Double-Blind, Three-arm, Parallel, Placebo-Controlled StudyClinicalTrials.gov ↗51 participants, Completed
- Clinical trialEffect of Ashwagandha (Withania Somnifera) as an Adjunct to Scaling and Root Planing on Salivary Antioxidant and Serum c Reactive Protein Levels in Chronic Generalized Periodontitis- a Randomized Double Blind Clinico-biochemical TrialClinicalTrials.gov ↗Phase 1, 50 participants, Completed
- Clinical trialEfficacy and Safety of Ashwagandha (Withania Somnifera) Root Extract on Stress, Anxiety, and Sleep Quality in Adults Experiencing Minority Stress: A Randomized, Double-Blind, Placebo-Controlled StudyClinicalTrials.gov ↗80 participants, Recruiting
- Clinical trialEffects of Root Extract Ashwagandha (KSM-66) on Physiological Stress, Perception of Recovery and Muscle Strength in Youth FootballersClinicalTrials.gov ↗62 participants, Suspended
From clinical trials and PubMed, ranked by study type and citation weight, not cherry-picked.
Problems people have reported.
Read this carefully. These are 800 voluntary, unverified reactions reported to the FDA (openFDA). The number mostly reflects how popular Ashwagandha is, not how risky it is. A report is not proof Ashwagandha caused anything. It is a signal of what to watch for, nothing more.
3 more reported effects
Source: openFDA adverse-event reports. Voluntary reporting, not an incidence rate.
Ashwagandha under a brand name
Companies sell ashwagandha under their own names. Each one below says what it is, who makes it and which verified products carry it.
Made by Arjuna Natural, Ixoreal Biomed, Natreon and Specnova.
FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. This information is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Consult your healthcare provider before starting any supplement regimen.