Ashwagandha: benefits, dosage, contraindications
Other name(s)
Indian ginseng
Scientific name(s)
Withania somnifera, Physalis somnifera
Family or group:
Plants
Active ingredients:
Saponins
Alkaloids
steroidal lactones
Beta-sitosterol
Withanolides
Indications
Scoring methodology
EFSA approval.
Stress ✪✪✪✪✪
Clinical studies show that taking a specific ashwagandha root extract at a dose of 300 mg twice daily after a meal for 60 days reduces perceived stress levels by 30% and cortisol levels by 28% compared with baseline in adults suffering from chronic stress. These improvements are significant compared with changes observed in patients treated with placebo. The ashwagandha root extract also appears to prevent stress-related weight gain compared with placebo.
Posologie
Oral: root
600 mg
8 weeks
KSM-66, dry extract
Body weight management in adults under chronic stress through treatment with ashwagandha root extract: a double-blind, randomized, placebo-controlled trial.
The Perceived Impact of Ashwagandha on Stress, Sleep Quality, Energy, and Mental Clarity for College Students: Qualitative Analysis of a Double-Blind Randomized Control Trial
An investigation into the stress-relieving and pharmacological actions of an ashwagandha (Withania somnifera) extract: A randomized, double-blind, placebo-controlled study
A Standardized Withania Somnifera Extract Significantly Reduces Stress-Related Parameters in Chronically Stressed Humans: A Double-Blind, Randomized, Placebo-Controlled Study
Efficacy and Safety of Ashwagandha Root Extract on Cognitive Functions in Healthy, Stressed Adults: A Randomized, Double-Blind, Placebo-Controlled Study
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.
Anxiety ✪✪✪✪✪
Supplementation with an Ashwagandha extract appears to improve anxiety symptoms such as fatigue, loss of appetite, headaches, and muscle pain. In one clinical trial, 300 mg of Ashwagandha root extract twice daily for 12 weeks reduced anxiety scores compared with a control group. In another clinical trial, taking Ashwagandha root powder granules at 4 g three times daily for 60 days moderately improved anxious mood in 58% of patients, versus no improvement in the placebo group. Other clinical research conducted in young adults shows that a root-and-leaf Ashwagandha extract, at doses of 225 mg or 400 mg per day for 30 days, produced similar improvements in self-reported anxiety, stress, and depression scores compared with placebo.
Posologie
Oral: root
600 mg
8 weeks
KSM-66, dry extract
A standardized Withania somnifera extract significantly reduces stress-related parameters in chronically stressed humans: a double-blind, randomized, placebo-controlled study.
Naturopathic care for anxiety: a randomized controlled trial ISRCTN78958974
Does Ashwagandha supplementation have a beneficial effect on the management of anxiety and stress? A systematic review and meta-analysis of randomized controlled trials
Clinician guidelines for the treatment of psychiatric disorders with nutraceuticals and phytoceuticals: the World Federation of Societies of Biological Psychiatry (WFSBP) and Canadian Network for Mood and Anxiety Treatments (CANMAT) Taskforce
A prospective, randomized double-blind, placebo-controlled study of the safety and efficacy of a high-concentration, full-spectrum extract of ashwagandha root in reducing stress and anxiety in adults.
Assessment of the efficacy of Withania somnifera root extract in patients with generalized anxiety disorder: a randomized double-blind, placebo-controlled trial
Efficacy of Withania somnifera supplementation on adults' cognition and mood
Male fertility disorders ✪✪✪✪✪
Supplementation with Ashwagandha may increase libido and pleasure in men. In a clinical trial, Ashwagandha root powder administered at 5 g per day for three months reduced oxidative stress and improved semen quality, testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and prolactin in a clinical trial of 150 infertile Indian men. Sperm count and motility were also improved. In another clinical trial, men with oligospermia who took an Ashwagandha root extract at 225 mg three times a day for 12 weeks noted improvements in semen parameters, namely motility and concentration.
Posologie
Oral: root
600 mg
12 weeks
Men
dry extract
Efficacy and safety of ashwagandha (withania somnifera) root extract in improving sexual function in women: a pilot study.
Efficacy of Withania somnifera on seminal plasma metabolites of infertile males: a proton NMR study at 800 MHz
Clinical Evaluation of the Spermatogenic Activity of the Root Extract of Ashwagandha (Withania somnifera) in Oligospermic Males: A Pilot Study.
Withania somnifera Improves Semen Quality in Stress-Related Male Fertility
Sleep disorders ✪✪✪✪✪
A small meta-analysis conducted in patients with insomnia and in healthy subjects shows that taking a specific ashwagandha root extract (KSM-66, Ixoreal Biomed) at a dose of 250-600 mg per day for 6 to 12 weeks modestly improves overall sleep, as well as sleep quality, sleep onset latency, total sleep time, wake time after sleep onset and sleep efficiency, compared with placebo. nnThe effects were more pronounced in people with insomnia, with doses of at least 600 mg per day, and with treatment durations of at least 8 weeks. nnThe effects remain positive even in patients with non-restorative sleep.nn
Posologie
Oral: root
600 mg
KSM-66, dry extract
Effect of Ashwagandha (Withania somnifera) extract on sleep: A systematic review and meta-analysis
A randomized, double blind, placebo controlled study to evaluate the effects of ashwagandha (Withania somnifera) extract on sleep quality in healthy adults
Clinical evaluation of the pharmacological impact of ashwagandha root extract on sleep in healthy volunteers and insomnia patients: A double-blind, randomized, parallel-group, placebo-controlled study
Sports performance ✪✪✪✪✪
A meta-analysis of four small clinical trials shows that taking Ashwagandha increases aerobic capacity in athletes and non-athletes, based on the measurement of maximal oxygen consumption. Effective doses ranged from 500 to 1000 mg per day for periods of up to 12 weeks. Positive results on muscle strength, speed, endurance, and recovery time were observed in other studies with doses ranging from 120 mg to 1250 mg per day. However, the validity of these analyses remains limited by the absence of control groups and the wide variety of training regimens.
Posologie
Oral: root
500 - 1000 mg
dry extract
Hypothyroidism ✪✪✪✪✪
A clinical study conducted in adults with subclinical hypothyroidism shows that taking an Ashwagandha root extract at 300 mg twice daily for 8 weeks can increase levels of two thyroid hormones, T3 and T4, and decrease TSH levels (a hormone that stimulates the thyroid) by 17.4% from baseline. These changes were significant compared with placebo. However, the long-term effects of Ashwagandha on thyroid hormone levels, as well as its effects in patients with clinical hypothyroidism, are not known to date.
Posologie
Oral: root
600 mg
8 - weeks
dry extract
Bipolar disorder ✪✪✪✪✪
Ashwagandha may improve cognitive function in patients with bipolar disorder. However, this improvement is very modest compared with placebo.
Posologie
Oral: root
250 - 500 mg
8 - weeks
dry extract
Attention deficit disorders ✪✪✪✪✪
A synergy including stimulants such as Ashwagandha, Bacopa and Centella asiatica; spirulina helps reduce behavioral problems associated with ADHD in children aged 6 to 12 years.
Posologie
Oral: root
300 mg
dry extract
Synergies
Fatigue ✪✪✪✪✪
Thanks to its adaptogenic properties, Ashwagandha can reduce perceived fatigue and increase vitality in some clinical studies. Note that a slight increase in testosterone and DHEA-S levels has been observed, which may partly explain the results. Additionally, Ashwagandha is traditionally used in infectious conditions and as an adjuvant in diseases caused by insufficient immune defenses.
Posologie
Oral: root
300 - 2000 mg
dry extract
A Randomized, Double-Blind, Placebo-Controlled, Crossover Study Examining the Hormonal and Vitality Effects of Ashwagandha ( Withania somnifera) in Aging, Overweight Males
Rheumatism ✪✪✪✪✪
In patients with osteoarthritis, taking a combined supplement containing 450 mg of Ashwagandha, 50 mg of an Ayurvedic zinc complex, 100 mg of Guggul, and 50 mg of Turmeric, three times a day for 3 months, reduces symptoms of pain and swelling compared with placebo. However, no radiological improvement was observed. Ashwagandha is traditionally used in rheumatic conditions (including autoimmune factors).
Posologie
Oral: root
450 mg
dry extract
Synergies
Sexual disorders ✪✪✪✪✪
A small clinical study conducted in adult women suffering from sexual dysfunction shows that taking a standardized Ashwagandha root extract (KSM-66) at 300 mg twice daily with meals for 8 weeks, alongside other counseling, increases the frequency of sexual intercourse, and improves orgasms, satisfaction, lubrication, and arousal, compared with care without supplementation.
Posologie
Oral: root
600 mg
KSM-66, dry extract
Cognitive performance ✪✪✪✪✪
Animal and human research suggests that Ashwagandha improves memory. A small single-center, double-blind clinical trial conducted on 50 people with symptoms of mild cognitive impairment, in which participants were divided into two groups: one received 300 mg of Ashwagandha root extract twice daily for 8 weeks and the other received a placebo. Analysis showed that daily treatment with Ashwagandha significantly improved performance on cognitive tests assessing memory, executive function, and information processing speed compared with placebo. In contrast, effects on working memory and visuospatial processing were inconclusive. Ashwagandha has antioxidant and neuroprotective activities. Its constituents are effective acetylcholinesterase inhibitors, which suggests its usefulness in the treatment of Alzheimer's disease.
Posologie
Oral: root
600 mg
7 weeks
dry extract
Efficacy and Safety of Ashwagandha (Withania somnifera (L.) Dunal) Root Extract in Improving Memory and Cognitive Functions
Withanolides, a new class of natural cholinesterase inhibitors with calcium antagonistic properties
[Overcoming several neurodegenerative diseases by traditional medicines: the development of therapeutic medicines and unraveling pathophysiological mechanisms]
Immunomodulatory and CNS effects of sitoindosides IX and X, two new glycowithanolides from Withania somnifera
Properties
Adaptogen
Ashwagandha is known as an adaptogenic plant, which may be due to withanolide glycosides. Adaptogens tend to reduce the perception of stress. Although the mechanism is not well understood in the case of Ashwagandha, it may be related to preventing a stress-induced increase in NADPH diaphorase. On the other hand, this anti-stress effect appears to be linked to the attenuation of serum corticosteroid levels, hormones often elevated in response to stress. Studies also indicate that Ashwagandha may reduce the stress-induced increase in dopamine receptors, a neurotransmitter, in a brain region called the corpus striatum, which is affected by stress. There are also anxiety-reducing effects secondary to the anti-stress properties, but Ashwagandha may also exert direct effects (via serotonergic and GABAergic signaling).
Usages associés
Effect of Withania somnifera (Ashwagandha) on the development of chemotherapy-induced fatigue and quality of life in breast cancer patients
A Randomized, Double-Blind, Placebo-Controlled, Crossover Study Examining the Hormonal and Vitality Effects of Ashwagandha ( Withania somnifera) in Aging, Overweight Males
Anxiolytic
The components of Ashwagandha have an effect similar to that of GABA, a neurotransmitter that helps reduce anxiety. Animal research has shown that Ashwagandha may also increase serotonin activity, another neurotransmitter linked to well-being and relaxation, by acting on postsynaptic serotonin receptors (the communication area between nerve cells).
Usages associés
Immunomodulatory
Ashwagandha and its components, notably withanolides and sitoindosides, appear to have immunomodulatory effects. They stimulate the activity of macrophages, which are important immune cells in fighting infections, and promote phagocytosis (the removal of unwanted particles) as well as the activity of lysosomal enzymes, which break down cellular waste. In addition, Ashwagandha may reduce the immunosuppression and decrease in white blood cells caused by cyclophosphamide, a drug used in cancer treatment. It has also been observed that Ashwagandha increases the number of cells in the bone marrow and the number of white blood cells in animals that have undergone radiotherapy.
Usages associés
Hormone metabolism
Ashwagandha appears to stimulate the synthesis and/or secretion of thyroid hormones. In clinical and animal research, Ashwagandha appears to stimulate thyroid function, with an increase in serum concentrations of triiodothyronine (T3) and thyroxine (T4) and a reduction in serum levels of thyroid-stimulating hormone (TSH). On the other hand, Ashwagandha appears to increase fertility in infertile men (who have reduced testosterone production). Indeed, in infertile men, Ashwagandha may improve sperm quality in terms of hormone levels (increased testosterone and LH levels, and decreased FSH and prolactin levels) but also in terms of sperm count and motility. However, Ashwagandha does not appear to affect fertility in otherwise healthy men.
Usages associés
Effect on fertility
In clinical research, Ashwagandha may improve sperm count and motility in adult men. These effects appear to be related to improved levels of testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and prolactin.
Usages associés
Sedative
Animal studies suggest that Ashwaganda has sedative properties on the central nervous system. Ashwaganda promotes sleep due to its potentiating effect on signaling via GABA-A receptors.
Usages associés
Anti-inflammatory
In the laboratory, a root extract of Ashwagandha demonstrated anti-inflammatory properties in cartilage taken from patients with chronic arthritis following a moderate inhibition of nitric oxide release. On the other hand, in stressed mice, the observed reduction in macrophage activity during stress appears to be significantly reduced by oral ingestion of Ashwagandha at relatively low doses.
Cognitive function
Studies in animals and humans indicate that Ashwagandha or its constituents may improve memory. This improvement could be due to the restoration of connections between nerve cells in the brain, or to strengthening of the myelin sheath, which surrounds and protects the nerves. In addition, in laboratory studies, withanolides, components of Ashwagandha, have shown the ability to inhibit an enzyme called cholinesterase, which is involved in brain function. It should be noted that cholinesterase inhibitors are often used in the treatment of neurodegenerative diseases, such as Alzheimer's disease. However, research in humans is mainly limited to subjects suffering from cognitive disorders, anxiety, or bipolar disorder. It is not yet clearly established whether Ashwagandha can also improve memory in healthy individuals.
Usages associés
Safe dosage
Adults 18 years and older: 300 mg - 600 mg
Ashwagandha has been used safely in clinical trials for periods of up to 12 weeks. Often the extract is standardized to 2% or 5% withanolides.
Interactions
Médicaments
Antidiabetic medications: minor interaction
Ashwagandha may have a hypoglycemic effect and thus can interfere with antidiabetic medications and increase the risk of hypoglycemia.
Antihypertensive medications: minor interaction
Ashwagandha may have hypotensive effects, and therefore it can interfere with antihypertensive medications.
Benzodiazepines: moderate interaction
Ashwagandha is an anxiolytic, so it may have an additive effect with other anxiolytic medications such as benzodiazepines.
Immunosuppressants: moderate interaction
Ashwagandha reduces the effectiveness of immunosuppressants due to its immunostimulatory action.
Thyroid hormone medications: moderate interaction
Clinical research and animal studies suggest that Ashwagandha stimulates the synthesis and secretion of thyroid hormones. Concurrent use of Ashwagandha and thyroid hormones may lead to undesirable therapeutic effects.
Precautions
Breastfeeding: avoid
Ashwagandha should be avoided in breastfeeding women due to a lack of reliable information.
Autoimmune diseases: avoid
Ashwagandha has demonstrated immunostimulant effects in humans and may exacerbate autoimmune diseases by stimulating immune activity. Use with caution in patients with autoimmune diseases such as multiple sclerosis, systemic lupus erythematosus, rheumatoid arthritis, or other autoimmune disorders.
Hyperthyroidism: avoid
Theoretically, Ashwagandha could exacerbate hyperthyroidism by increasing thyroid hormone levels; use with caution in patients with hyperthyroidism or those treated with thyroid hormones.
Contraindications
Pregnant women: contraindicated
Ashwagandha causes spontaneous abortions; therefore, it is contraindicated in pregnant women.
