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Ashwagandha - Withania somnifera - Monograph

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What is ashwagandha? Where is Withania somnifera found? What are the benefits of ashwagandha? What are its active ingredients? What are the effects of ashwagandha on stress and cortisol?


Ashwagandha (Withania somnifera dunal)

Withania somnifera or ashwagandha is a plant traditionally used in Ayurvedic medicine in its simple form and in combination with other plants.

Preclinical studies indicate an antimicrobial, anti-inflammatory, neuroprotective, anxiolytic and cardioprotective effect. (Nawab 2015).

Ashwagandha is considered as an excellent adaptogen.

This terminology was proposed by the Russian Doctor Israel Brekhman (Brekhman 1969).





Common names: Withania, Indian ginseng and in Sanskrit: ashwagandha.

Family: Solanaceae



Native to India, this plant has spread to the Far East and the Mediterranean. It can even be found in parts of southern Spain. The plant grows wild and is also cultivated for medicinal purposes.



Bushy, somewhat woody plant, up to 1.5 m high, with a pubescent stem and greyish or whitish hair. The flowers are axillary, in groups of three or four, short-stemmed and with a yellowish-green corolla. The fruit is a small orange berry, about the size of a pea, which, before ripening, is covered by a calyx.


Origin of the name "Ashwagandha"

The fresh roots of the plant have a strong and somewhat unpleasant odor, similar to that of horse sweat, from which it derives its Sanskrit name Ashwa-gandha, which means "horse smell".



Withania somnifera (Ashwagandha) is a botanical plant used for its roots in Ayurvedic medicine. The root is said to have similar properties to Chinese ginseng, hence its name "Indian ginseng" in Europe.



The main chemical constituents of ashwagandha are: withanolides (steroidal lactones, especially withaferin A), alkaloids piperidinic and pyrazolic (anaferine, tropine), phytosterols and flavonoids.

From a pharmacological point of view, the active ingredients are essentially withanolides, with a chemical structure similar to that of many solanaceous plants (tomatoes, potatoes, aubergines, chillies etc...).


Benefits and applications of ashwagandha roots

In the traditional Ayurvedic medicine, ashwagandha is known as "a good remedy to achieve longevity."

It is a relaxing and calming herb, which, along with its adaptogenic effect, makes it particularly interesting for managing stress.

In addition, it is considered as an immunomodulator, and antioxidant.

Finally, it is also known to increase SOD (superoxide dismutase) activity and strengthen the immune system (Birla 2019).


Ashwagandha and stress

Ashwagandha exhibits cholinergic activity. Indeed, it is thought to increase the activity of acetylcholine and of choline acetyltransferase (Schliebs 1997).


A meta-analysis of the various studies on the efficacy of ashwagandha on anxiety and stress was conducted (Pratte 2014). Five clinical studies met the selection criteria and measured anxiety and/or stress scores.

All five studies concluded that intervention with Withania somnifera resulted in greater improvement (significant in most cases) than placebo of the stress scales.

Stress and weight gain relationship

Because of the relationship between stress and weight gain, ashwagandha has been shown to be effective as a complementary treatment for weight loss in stressed individuals by reducing cravings during the day (Choudhary 2017).

Effect on cortisol levels

In stressed adult individuals, taking ashwagandha root extract for 60 days produced a significant reduction (P<0.0001) in all stress scales compared to the placebo group. Also, the authors reported a significant decrease (P=0.0006) in serum cortisol levels after two months of intake (Chandrasekhar 2012).


Benefits of ashwagandha and mood

GABA mimetic action

Preclinical studies suggest that ashwagandha contains an ingredient with a GABA-mimetic action, inhibiting 5-Hydroxytryptophan (5-HTP) receptors and stimulating 5-HTP2 receptors. This action results in reduced levels of anxiety and depression in animal models. (Candelario 2015)

The relaxing and calming effect of ashwagandha

At doses of 1 g/day, the effect of ashwagandha on mood has been shown to be significant after 15 days of treatment.

Similarly, in medium-term studies, it has been observed that the effect does not diminish right away after 18 months of continuous treatment. 

Also, the calming effect of withanolides has been demonstrated in laboratory animals by administering 20-50 mg/kg for 5 days, comparing the results with those of lorazepam and imipramine. (Bhattacharya 2000).

Finally, one study shows a calming dose-response relationship at daily doses between 125 and 500 mg (Auddy 2008).


Ashwagandha and intellectual performance

A clinical study demonstrated the stimulating effect of ashwagandha on memory (Pingali 2014).

Two 250 mg capsules of aqueous extract of ashwagandha roots were administered daily. Cognitive and intellectual performance tests were performed before admission, 3 hours after admission and again on the 15th day after administration.

In this study, it is concluded that ashwagandha improves reaction time compared to placebo. Similarly, it improves vigilance and card-sorting test scores.


Contraindications - Precautions

Ashwagandha is not recommended for pregnant women.

People with psychiatric problems should seek the advice of their doctor before consuming ashwagandha.

Consumption of this herb increases T3 and T4 levels in laboratory animals. Therefore, the use of this supplement in people with hyperthyroidism should be evaluated by a physician.


Recommended daily doses

The usual dose is 3-6 g of herb per day.

The usual titration of withanolides in extracts varies from 3 to 8%. A dosage of 300-600 mg dry extract per day may be recommended as supplement of ashwagandha root extract.


Ashwagandha dietary supplement / ashwagandha capsule supplement

Optim Serenity is a dietary supplement made from Ashwagandha (Withania somnifera) and Rhodiola Rosea. These two adaptogenic herbs help to manage stress and mental fatigue. The supplement comes in the form of plant-based capsules easy to swallow.




Auddy et al (2008)A Standardized Withania Somnifera Extract Significantly Reduces Stress-Related Parameters in Chronically Stressed Humans: A Double-Blind, Randomized, Placebo-Controlled Study, JANA, Vol 11, 1, Pages 50-58.

Bhattacharya SK et al (2000): Anxiolytic-antidepressant activity of Withania somnifera glycowithanolides: an experimental study. Phytomedicine, Volume 7, Issue 6, December 2000, Pages 463-469.

Birla H et al (2019): Neuroprotective effects of Withania somnifera in BPA-induced-cognitive dysfunction and oxidative stress in mice. Behav Brain Funct. 2019 May 7;15(1):9.

Brekhman I et al (1969). New substances of plant origin which increase nonspecific resistance. Ann Rev Pharmacol 9: 419-30

Candelario M et al (2015): Direct evidence for GABAergic activity of Withania somnifera on mammalian ionotropic GABA A and GABAr receptors. J Ethnopharmacol. 2015; 171:264-272.

Chandrasekhar K et al (2012): 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 Jul-Sep; 34(3): 255-262.

Choudhary et al (2017): Body weight management in adults under chronic stress through treatment with Ashwagandha root extract: A double-blind, randomized, placebo-controlled trial. Journal of Evidence-Based Complementary & Alternative Medicine 2017, Vol. 22(1) 96-106

Nawab JD et al (2015): Pharmacologic overview of Withania somnifera,the Indian Ginseng. Cellular and Molecular Life Sciences, December 2015, Volume 72, Issue 23, pp 4445-4460.

Pingali U et al (2014): Effect of standardized aqueous extract of Withania somnifera on tests of cognitive and psychomotor performance in healthy human participants.Pharmacognosy Res. 2014 Jan;6(1):12-8.

Pratte A et al (2014): An Alternative Treatment for Anxiety: A Systematic Review of Human Trial Results Reported for the Ayurvedic Herb Ashwagandha (Withania somnifera). The Journal of Alternative and Complementary Medicine 20, No. 12, 901-908.

Schliebs R et al (1997) V: Systemic administration of refined extracts from Withania somnifera (Indian Ginseng) and Shilajit differentially affects cholinergic but not glutamatergic and GABAergic markers in rat brain. Neurochem Int. 1997, 30: 181-190.

Wagner H (1994): Plant adaptogens. Phytomedicine Volume 1, Issue 1, June 1994, Pages 63-76