Ashwagandha for Sleep, Health and Longevity


Ashwagandha (Withania somnifera) is an herb native to India, Pakistan and Sri Lanka. It is in the Solanaceae family, which also contains such plants as eggplant (Solanum melongena), belladonna (Atropa belladonna), cayenne pepper (Capsicum spp.), potato (Solanum tuberosum), tobacco (Nicotiana spp.) and tomato (Lycopersicon esculentum).

In India, Ashwagandha has been used medicinally for more than 3000 years. In Ayurvedic medicine, the traditional medical system in India, Ashwagandha is used alone and in combination with other herbs for musculoskeletal conditions (e.g., arthritis, rheumatism), and as a tonic to increase energy, improve overall health and longevity, and prevent disease in athletes, the elderly, and during pregnancy. Animal and human studies show that Ashwagandha possesses anti-inflammatory, antitumor, antistress, antioxidant, immunomodulatory, hematopoietic (stimulating red blood cell production), and rejuvenating properties.


The concept of adaptogenic herbs was coined in the 1950s by Russian scientists. Three criteria must be met for a medicinal plant to be considered an adaptogen (see Side Bar). Several popular herbs are considered adaptogens, including Siberian ginseng (Eleutherococcus senticosus), Rhodiola (Rhodiola rosacea), and Ashwagandha.

Many people suffer the effects of chronic stress. Ashwagandha may be an important herb for helping protect the body from stress. In an animal study, rats were injected with100 mg/kg Ashwagandha root extract and then placed in water. The amount of time they were able to swim indicated an increased ability to handle stress, and increased stamina. The rats who received ashwagandha swam for nearly twice as long as those that didn’t get the ashwagandha.2 Another study on rats and frogs administered 100 mg/kg ashwagandha to these animals.3 This study confirmed the positive effects of the previous study but also showed that glycogen (the storage form of sugars in the body) stored in the heart was eight times greater than before the experiment. Glycogen is the form of stored sugar that is used before fats during exercise, which might explain the increased stamina in animals taking Ashwagandha.  

Cortisone is a hormone released by the adrenal glands (a gland that sits atop each kidney) in response to stress. Ashwagandha was evaluated for its ability to decrease the release of cortisone under stressful conditions. Rats received 100 mg/kg Ashwagandha orally per day for 7 days and then placed in cold water (10oC) to swim until exhaustion. Those rats who consumed Ashwagandha had near normal levels of cortisol compared to control rats who did not receive Ashwagandha. At least three other studies have confirmed these positive effects of ashwagandha on stress.

Criteria for Defining an Adaptogen

  1. Produces a non-specific response; e.g., increases the ability to resist the detrimental effects of multiple stressors, including from physical, chemical, or biological agents.
  2. Normalizes physiology, irrespective of change from physiological norms caused by the stressor.
  3. Does not influence normal body functions more than required to gain non-specific resistance.


Ashwagandha is widely known for its antioxidant, relaxing and adaptogenic effects. In an animal study, rats were given 100 mg/kg body weight of Ashwagandha extract. Animals were made uncomfortable to keep them awake longer and have more disturbed sleep. Rats treated with Ashwagandha fell asleep faster, woke up less and had more total sleep than disturbed rats. The authors concluded that Ashwagandha promotes sleep and may be helpful for sleep and related problems. This research supports the traditional uses of Ashwagandha to promote relaxation and sleep. Based on modern research and the traditional uses of Ashwagandha, NBI includes this sleep- and health-promoting herb in Sleep Relief.

Immune Modulation

Ashwagandha has been used historically to help improve immune function, and modern research has verified this ancient knowledge. The research provides additional support for the adaptogenic properties of Ashwagandha, as the herb appears to have a normalizing effect on the immune system. Ashwagandha was studied for its ability to decrease experimentally-induced allergic reactions in animals. Rats were fed Ashwagandha for five days, and then a paw on each animal was injected with a substance to induce swelling (an allergic reaction). At a dose of 150 mg/kg Ashwagandha swelling decreased by approximately 42% and at 300 mg/kg Ashwagandha by approximately 45% compared to rats that did not receive the herb.

Immune suppression is a side effect of radiotherapy and chemotherapy treatments for cancer. Mice received the immunosuppressive drug cyclophosphamide for ten days with or without concomitant administration of Ashwagandha. After 10 days of treatment, the mice that received Ashwagandha showed greater bone marrow cellularity (an indicator of the bone’s ability to produce oxygen-carrying red blood cells and immune-enhancing white blood cells), increased body weight, and normal intestinal cells compared with those mice treated just with cyclophosphamide. Human studies are lacking, but if Ashwagandha can be shown to have similar positive effects in people undergoing cancer treatment, this herb may be an important addition to conventional cancer treatments.

Herb-Drug Interactions

Since ashwagandha can increase immune system function, anyone on immune-suppressive therapies (e.g., prednisone, cyclosporine) should not take ashwagandha. If you are taking any medications, consult a healthcare professional knowledgeable in herb-drug interactions.


Allergies to any plants in the Solanaceae family (e.g., potato, tomato, eggplant) increase your risk for allergic reactions to Ashwagandha, since it is in the same family as these other plants.


  • Dried root: 3–6 g/day
  • Root extract standardized to 1.5% withanolides: 300–500 mg/day
  • 1:2 fluid extract: 6–12 ml/day

Agarwal R, Diwanay S, Patki P, Patwardhan B. Studies on immunomodulatory activity of Withania somnifera (Ashwagandha) extracts in experimental immune inflammation. J Ethnopharmacol. Oct 1999;67(1):27-35. [Article]

Archana R, Namasivayam A. Antistressor effect of Withania somnifera. Journal of Ethnopharmacology. 1999;64(1):91-93. [Article]

Davis L, Kuttan G. Suppressive effect of cyclophosphamide-induced toxicity by Withania somnifera extract in mice. Journal of Ethnopharmacology. 1998;62(3):209-214. [Article]

Kelly GS. Rhodiola rosea: A possible plant adaptogen. Altern Med Rev. 2001;6(3):293-302. [Article]

Kumar A, Kalonia H. Effect of Withania somnifera on Sleep-Wake Cycle in Sleep-Disturbed Rats: Possible GABAergic Mechanism. Indian J Pharm Sci. 2008;70(6):806-810. [Article]

Mishra L-C, Singh BB, Dagenais S. Scientific basis for the therapeutic use of Withania somnifera (Ashwagandha): a review. Altern Med Rev. 2000;5(4):334-346. [Article]

Monograph: Withania somnifera. Altern Med Rev. 2004;9(2):211-214. [Article]

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