Ashwagandha

important Ashwagandha facts

Ashwagandha is small evergreen shrub in the Solanaceae (nightshade) family. It is known as an adaptogen, which means it helps the body adapt to physical, emotional, and environmental stress. It helps to promote balance in the body without stimulating or sedating. It works to support multiple body systems at once in ways that the body need.

• It grows mainly in India, the Middle East, and parts of Africa
• Known as Indian ginseng (though unrelated to Panax ginseng) and winter cherry
• In Sanskrit, Ashwagandha means smell of horse (ashwa = horse, gandha = smell), referring to the root’s odour and its traditional association with strength and vitality
• Used for over 3,000 years in Ayurveda as a rasayana (rejuvenating tonic)
• Believed to promote strength, stamina, longevity, and resilience to stress
• It is also known as Withania

Ashwagandha’s adaptogenic actions

• HPA axis regulation – this means Ashwagandha modulates the hypothalamic-pituitary-adrenal (HPA) axis, which governs stress response. This lowers cortisol levels in clinical trials, reducing the physiological burden of chronic stress
• Neurotransmitter balance – it influences GABA’s neurotransmitter activity by calming it and possibly affects serotonin pathways in positive ways. It supports relaxation without causing sedation
• Immune modulation – it enhances the immune response when it’s low, but doesn’t overstimulate stress-related immune dysfunction. This bidirectional effect is typical of adaptogens
• Energy and resilience – traditionally believed to impart the strength of a horse

In modern times, it’s one of the most researched adaptogens, studied for stress reduction, sleep improvement, athletic performance, and cognitive health. Studies show improvements in energy, endurance, and recovery without being a stimulant.

Ashwagandha and health

Ashwagandha is considered good for health because it supports whole body balance. It reduces stress, enhances energy, improves sleep and strengthens both physical and mental resilience. Health benefits in detail include:

Stress reduction

• Ashwagandha is one of the best studied adaptogens
• Clinical trials show it can reduce cortisol (the stress hormone) and lower scores on validated anxiety and stress scales
• Works by modulating the HPA axis (hypothalamic–pituitary–adrenal system), which regulates the stress responses

Improved sleep

• Shown to increase total sleep time and sleep quality in people with insomnia and poor sleep patterns
• Appears to improve both sleep onset (falling asleep faster) and sleep maintenance (fewer awakenings)
• Works by calming the nervous system, partly through the effect of the neurotransmitter GABA

Energy and vitality

• Traditionally used as a rasayana (rejuvenator) in Ayurveda for improving stamina and resilience
• Studies in healthy adults and athletes show improvements in energy, endurance and reduced fatigue
• Provides steady support without being a stimulant

Cognitive support

• Preliminary evidence suggests better memory, focus and information processing speed
• Believed to protect brain cells from oxidative stress and support neurotransmitter balance
• May help reduce “mental fog” associated with stress and fatigue

Physical performance

• Multiple trials report improvements in muscle strength, aerobic capacity (VO₂ max) and recovery when combined with training
• Useful for athletes and those looking to improve exercise performance or recovery

Immune modulation

• Supports both innate and adaptive immunity
• Can boost immune response when low, but also reduce excess inflammation — a hallmark of adaptogens
• This balancing effect may help with resilience to infections and stress-related immune suppression

Metabolic benefits

• Some studies show there are improvements in fasting blood sugar and cholesterol levels
• May support insulin sensitivity and reduce oxidative stress that contributes to metabolic syndrome

Hormonal and reproductive health

• Traditionally prescribed for male fertility and vitality
• Research shows it can improve sperm count, motility and testosterone levels in men with fertility concerns
• May also help with stress-related reproductive hormone imbalances in women

Deficiency

There is no known deficiency in Ashwagandha as it isnt vital to human health. Some people might want to take it for specific health concerns:

Stress and anxiety

• Clinical studies show ashwagandha lowers cortisol (the body’s main stress hormone)
• Helps regulate the HPA axis (hypothalamic–pituitary–adrenal system), improving how the body adapts to stress
• Can reduce symptoms of generalised anxiety, tension and stress-related fatigue

Sleep issues

• Shown to improve both sleep onset and quality, particularly in people with insomnia
• May enhance slow-wave sleep (deep, restorative sleep stages)
• Does not act like a sedative but calms the nervous system via GABA-like activity

Low energy or vitality

• Used in Ayurveda as a rasayana (rejuvenation) for stamina, strength and recovery
• Helps reduce fatigue linked to stress or illness
• Provides steady energy without over-stimulation, unlike caffeine

Cognitive support

• Recent studies suggest it provides improvements in working memory, focus and reaction time
• Protects neurons against oxidative stress and inflammation, supporting long-term brain health
• May reduce “mental fog” and improve mental clarity under stress

Exercise and recovery

• Clinical trials show increases in muscle strength, muscle size and endurance when combined with resistance training
• Improves VO₂ max (aerobic capacity), meaning better cardiovascular fitness
• May reduce exercise-induced muscle damage and speed up recovery

Metabolic balance

• Studies indicate support for healthy blood sugar regulation by improving insulin sensitivity
• May reduce LDL (bad) cholesterol and triglycerides while supporting HDL (good) cholesterol
• Antioxidant effects may reduce oxidative stress that contributes to metabolic syndrome

Reproductive health

• In men, research shows improvements in sperm count, motility and testosterone levels, especially in stress-related infertility
• Traditionally used to promote male vitality and reproductive strength
• Some studies suggest potential for women with stress-related menstrual cycle irregularities, though more research is needed

Immune resilience

• This balancing effect supports resilience during times of chronic stress or illness
• Acts as an immune modulator, helping balance both under-active and over-active immune responses
• May increase white blood cell activity when needed (low immunity), yet calm excessive inflammation

Ashwagandha food sources

Ashwagandha is not a dietary nutrient. It can only be obtained from the root and leaves of ashwagandha and supplements

Types of ashwagandha supplements

Root powder (traditional form)

• Finely ground dried root
• Commonly used in Ayurveda mixed into warm milk, ghee, honey or water
• Typical dosage: 3–6 g per day
• Less concentrated, larger amounts required for therapeutic effect

Standardised root extract

• Concentrated extract, usually standardised to 5% withanolides
• Most clinical studies use this form (e.g. KSM-66®, Sensoril®)
• Typical dosage: 300–600 mg per day
• Available in capsules, tablets or bulk powder

Capsules and tablets

• Convenient form containing root powder or standardised extract
• Common doses: 250–600 mg per capsule
• Usually taken once or twice daily with meals

Liquid extracts and tinctures

• Alcohol or glycerin-based liquid extracts
• Useful for faster absorption or those who prefer not to take capsules
• Dosage depends on concentration, typically 2–4 mL per day

Gummies

• Growing in popularity as a user-friendly option
• Contain measured amounts of extract, often 150–300 mg per gummy
• May be combined with other calming herbs (eg lemon balm, valerian)

Teas

• Usually combined with other herbs in herbal tea blends
• Dried root pieces or powder brewed into tea
• Less concentrated and often used for general wellbeing or relaxation

Key supplements info

• Extracts are stronger and better studied than raw powders or teas
• Powder and teas align more with traditional Ayurvedic practices
• Capsules and gummies are the most convenient and standardised for modern use

Ashwagandha recommended dosage

Standardised extract (root or root+leaf)

• 300–600 mg per day, usually divided into 1–2 doses
• Most clinical studies use KSM-66® or Sensoril® extracts standardised to 5% withanolides
• Shown effective for stress, anxiety, sleep, energy, and exercise performance

Root powder (traditional form)

• 3–6 g per day, typically taken as a powder mixed into warm milk, water or honey in Ayurveda
• Less concentrated than extracts, so higher amounts are required

Capsules or tablets

• Common strengths: 250 mg, 500 mg, or 600 mg
• Usually taken once or twice daily with food

Liquid extracts/tinctures

• Dosage depends on concentration (e.g. 1:1 or 1:2 extracts)
• Typically 2–4 mL per day, in divided doses

Timing

• Can be taken morning or evening
• If used for energy, morning is best
• If used for sleep or stress relief, evening is preferred

Key dosage info

• Benefits are usually seen after 6–8 weeks of consistent use
• Higher doses (up to 1,000 mg/day of extract) have been used in short-term studies, but long-term safety data is limited
• Always best to start low and increase gradually under guidance

Overdosage, toxicity and side effects

Overdosage

• Very high intakes of crude powder (e.g. >10 g/day) are not well studied and may pose risks
• Clinical doses are usually 300–600 mg/day of standardised root extract (sometimes up to 1,000 mg/day short term)
• Overdosage above 1,500–2,000 mg/day may increase the likelihood of side effects

Toxicity

• Ashwagandha is generally considered low in toxicity when used in recommended amounts
• Animal studies show high safety margins, but extremely large doses can cause gastrointestinal distress and lethargy
• Toxicological data suggests caution with long-term high-dose use

Side effects (most are dose-related)

Common

• Stomach upset, diarrhoea or nausea
• Drowsiness or excessive sleepiness
• Headaches in sensitive individuals

Less common

• Increased thyroid hormone levels in some users
• Dizziness or drop in blood pressure (particularly with other antihypertensives)
• Vivid dreams or restlessness at higher doses

Rare but serious

• Liver toxicity (few case reports, usually reversible after stopping use)
• Allergic reactions (itching, rash, rarely swelling)
• Possible interactions with sedatives, thyroid medication, or immunosuppressants leading to unwanted effects

Precautions

Always use with caution if any of the following apply to you:

Pregnancy

• Traditionally contraindicated in pregnancy as it may stimulate uterine contractions
• Could increase the risk of miscarriage or preterm labour
• Not recommended unless specifically prescribed under medical supervision

Breastfeeding

• Insufficient safety data on use during lactation
• Possible risk of transfer through breast milk with unknown effects on infants
• Safer to avoid unless directed by a healthcare provider

Thyroid disorders

• Ashwagandha may increase thyroid hormone production (T3 and T4)
• Can be risky in hyperthyroidism or if taking thyroid hormone replacement (levothyroxine)
• Needs careful monitoring of thyroid function if used in hypothyroidism under practitioner guidance

Autoimmune conditions

• As an immune stimulant, it may worsen autoimmune activity in conditions like:
  • Rheumatoid arthritis
  • Systemic lupus erythematosus (SLE)
  • Multiple sclerosis (MS)
  • Hashimoto’s thyroiditis (caution if unstable)
• Should only be considered under medical advice in these situations

Diabetes and blood sugar disorders

• Ashwagandha can lower blood sugar, which may interact with:
  • Insulin injections
  • Oral hypoglycaemic drugs (metformin, sulfonylureas, etc)
• Risk of hypoglycaemia if not monitored

Low blood pressure or hypertension medication

• Can reduce blood pressure slightly
• May interact with blood lowering medications, leading to dizziness, fainting or hypotension (very low blood pressure)

Gastrointestinal conditions

• High doses may cause diarrhoea, nausea or stomach upset
• People with sensitive digestion, irritable bowel syndrome or ulcers should start with low doses or avoid if symptoms worsen

Before surgery

• Ashwagandha may affect blood sugar and interact with anaesthesia
• Best practice is to stop supplementation at least 2 weeks before scheduled surgery

People with liver concerns

• Very rare cases of liver damage have been reported (usually from high doses or poor-quality supplements)
• Should be used cautiously in those with existing liver disease or elevated liver enzymes

Interactions with Ashwagandha

Ashwagandha can adversely interact with a number of medications.

Sedatives, anti-anxiety or sleep medications

• Ashwagandha may enhance the effects of benzodiazepines (eg diazepam, lorazepam), barbiturates, prescription sleeping medications (zolpidem, eszopiclone)
• Could cause excess drowsiness or slowed reaction times if taken with these medications so it’s best to avoid mixing them

Thyroid medication

• Ashwagandha can increase thyroid hormone levels (T3 & T4)
• May interfere with levothyroxine or other thyroid medications, which increases the risk of hyperthyroidism symptoms (palpitations, anxiety, weight loss)

Blood sugar–lowering drugs

• Ashwagandha may reduce blood glucose
• Can interact with insulin injections, metformin
• May increase risk of hypoglycaemia

Blood pressure–lowering drugs

• Ashwagandha may reduce blood pressure slightly
• Increases the risk of hypotension (low blood pressure, dizziness, fainting)

Immunosuppressants

• Ashwagandha can stimulate immune activity
• May reduce the effectiveness of corticosteroid medications (prednisone, dexamethasone), biologics (adalimumab, infliximab)

Thyroactive herbs or supplements

• Combining with iodine, guggul, kelp or other thyroid boosters may cause overstimulation of the thyroid

CNS depressants (alcohol, opioids, antihistamines)

May enhance sedation and impair alertness so it’s best to avoid taking Ashwagandha with alcohol, opioids or antihistamines.

Food & supplement interactions

• Alcohol – can increase sedative effects and risk of liver stress at high doses
• Other calming herbs (valerian, kava, passionflower, hops, lemon balm) – may amplify drowsiness
• Adaptogens (rhodiola, ginseng, holy basil) – usually compatible, but combining multiple adaptogens should be monitored for overstimulation or hormonal effects
• Iron – some traditional use of ashwagandha with iron in Ayurveda, but no strong modern evidence. People with iron overload (eg haemochromatosis) should be cautious

Clinical caution

• Pre-surgery – may affect blood sugar and sedation. It’s recommended to stop taking ashwagandha at least 2 weeks before surgery
• Autoimmune conditions – ashwagandha may worsen disease activity due to immune stimulation

References

• 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;34:255-62
• Lopresti AL, Drummond PD, Smith SJ. A randomized double-blind placebo-controlled crossover study examining hormonal and vitality effects of ashwagandha in aging overweight males. Am J Mens Health 2019;13:1557988319835985
• Langade D, Kanchi S, Salve J et al. Efficacy and safety of ashwagandha (Withania somnifera) root extract on sleep in healthy subjects: a randomized, double-blind, placebo-controlled study and meta-analysis. PLoS One 2021;16:e0257843
• van der Watt G, Laugharne J, Janca A. The efficacy of ashwagandha for anxiety and stress: a systematic review and meta-analysis. BJPsych Open 2025;11:eXX [online ahead of print]
• Shenoy S, Chaskar U, Sandhu JS, Paadhi MM. Effect of ashwagandha (Withania somnifera) on VO₂max in elite cyclists: a randomized controlled trial. J Ethnopharmacol 2021;268:113594
• Khan S, Zargar F, Wani IA et al. Clinical evaluation of the spermatogenic activity of the root extract of ashwagandha in oligospermic males: a randomized placebo-controlled study. Evid Based Complement Alternat Med 2013;2013:571420
• Björnsson ES, Bergmann OM, Björnsson HK et al. Ashwagandha-induced liver injury: a case series from Iceland and the US Drug-Induced Liver Injury Network. Liver Int 2020;40:825-829
• Office of Dietary Supplements, National Institutes of Health. Ashwagandha: Is it helpful for stress, anxiety, or sleep? Fact Sheet for Consumers. NIH ODS 2023; updated Dec 4, 2023
• Health Canada. Ashwagandha (Withania somnifera) monograph. Natural Health Products Directorate, Health Canada 2024

Last reviewed and updated: 15 August 2025