Ashwagandha: What Does the Science Say?

By Deliana InfanteReviewed by Danielle Ellis, B.Sc.

What is ashwagandha?
Ashwagandha and stress: What does the science say?
Can ashwagandha help with anxiety and depression?
Ashwagandha and physical health: Immune system, inflammation, and more
Ashwagandha for athletic performance
References
Further reading

Ashwagandha, an adaptogenic herb, has been used for centuries in traditional medicine to combat stress and anxiety. Modern research suggests that it may help manage these conditions by regulating cortisol levels, the stress hormone. Studies indicate that ashwagandha supplementation can lead to significant reductions in anxiety symptoms and perceived stress levels, promoting a sense of calmness and well-being.

What is ashwagandha?

Ashwagandha, also known as Withania somnifera, has a rich history rooted in traditional Ayurvedic medicine, where it has been used for over 3,000 years.¹ Originating in India, its name translates to "smell of the horse," alluding to its distinct aroma and potential to impart the strength and vitality of a stallion.²

Revered as a Rasayana, a rejuvenating tonic, ashwagandha is classified as an adaptogen.^1-3 This means it helps the body adapt to stress by supporting its natural stress response system, promoting balance and resilience.³ It is used to address a wide range of health concerns, including stress and anxiety, where its calming properties help to reduce cortisol levels and promote a sense of tranquility.¹

It is believed to enhance memory, focus, and overall cognitive performance, as well as improve sleep quality and reduce insomnia. Ashwagandha is thought to boost the immune system and enhance the body's defense against illness, probably through its effects on cortisol levels.¹

By 2024, this plant's popularity has spread far beyond India, gaining recognition as a valuable natural remedy for stress management, anxiety relief, and overall well-being in complementary and alternative medicine systems worldwide.²

Ashwagandha and stress: What does the science say?

Several studies have highlighted the potential benefits of this plant for stress and anxiety management. Chandrasekhar et al. (2012)⁴ found that ashwagandha significantly reduced perceived stress and cortisol levels in chronically stressed adults, alongside improvements in sleep and well-being.

Similarly, Pandit et al. (2024)⁵ observed significant reductions in chronic stress and improved hypothalamic-pituitary-adrenal (HPA) axis function, known to be affected by long-term stress.

Salve et al. (2019)⁶ focused specifically on anxiety and stress, demonstrating that ashwagandha effectively reduced anxiety symptoms and cortisol levels. Interestingly, Chengappa et al. (2013)⁷ extended these findings to individuals with bipolar disorder, where ashwagandha also decreased stress and anxiety while improving cognitive function.

Although these studies provide compelling evidence, ongoing research continues to explore the full potential of ashwagandha for stress, anxiety, and cognitive health in diverse populations.

Can ashwagandha help with anxiety and depression?

Research suggests that ashwagandha may hold promise as a natural approach to managing depression. While the exact mechanisms are still being investigated, studies indicate that ashwagandha may influence serotonin and dopamine levels, key neurotransmitters involved in mood regulation.¹

Additionally, its potential anti-inflammatory effects may be relevant, as inflammation is increasingly recognized as a contributing factor to depression.¹ Studies in bipolar disorder and anxiety provide evidence that ashwagandha may be a valuable tool in managing mood disorders.⁷

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Furthermore, research has shown that ashwagandha has potential consequences in depression management by mimicking the effect of anti-depressive and anxiolytic drugs, suggesting that it may improve stress resilience and cognitive function, both of which are crucial for mental well-being.⁸

While these findings are encouraging, it's important to note that research on ashwagandha for depression is still in its early stages compared to conventional treatments like antidepressants and psychotherapy.

It's important to consult a physician before using ashwagandha. It should be considered a complementary approach, not a replacement for conventional treatments.

Ashwagandha and physical health: Immune system, inflammation, and more

Ashwagandha has been linked to improved immune function. A 2021 study explored its potential in healthy adults.⁹ The group receiving ashwagandha showed a significant increase in key immune system components, including immunoglobulins (IgA, IgM, IgG), cytokines (IFN-γ, IL4), and various types of immune cells (T cells, B cells, and natural killer cells).⁹ In contrast, the placebo group experienced a decrease in immune cell numbers. ⁹

Those who continued taking ashwagandha experienced further improvements. Importantly, no adverse side effects were reported throughout the study. ⁹

These findings suggest that ashwagandha extract can effectively modulate both the innate and adaptive immune systems, leading to a stronger immune response.⁹

Ashwagandha for athletic performance

Withania somnifera has shown promising results in improving athletic performance in several studies. Wankhede et al. (2015)¹⁰ found that combining ashwagandha supplementation with resistance training led to significant increases in muscle strength and size in healthy young men compared to a placebo group. 

Similarly, Ziegenfuss et al. (2018)¹¹ demonstrated that ashwagandha enhanced muscle strength and size gains in men engaged in resistance training. Shenoy et al. (2012)¹² examined the impact of ashwagandha on cardiorespiratory endurance in elite cyclists and found significant improvements in VO2 max and time to exhaustion, suggesting enhanced endurance capacity.

These findings suggest that ashwagandha can help maximize strength gains, improve endurance, and speed up muscle recovery, allowing for more frequent and intense training.

As a natural supplement, ashwagandha offers a safe and potentially effective alternative to synthetic performance enhancers. While further research is needed to elucidate the mechanisms behind these effects fully, ashwagandha appears to be a valuable tool for athletes and fitness enthusiasts seeking to optimize their performance.

Safety and side effects

Ashwagandha is generally safe for short-term use (up to 3 months) at appropriate dosages.² However, potential side effects include mild gastrointestinal issues, drowsiness, and rare allergic reactions.²

It is not recommended during pregnancy or breastfeeding, and caution is advised for those with thyroid disorders or autoimmune diseases, as it may interact with some of the medications.²  

In general, healthcare professionals should obtain a thorough patient history, provide individualized recommendations, monitor for side effects, and stay informed on the latest research and safety information.²  

References

1. Mikulska, P. et al. (2023). Ashwagandha (Withania somnifera)-Current Research on the Health-Promoting Activities: A Narrative Review. Pharmaceutics 15. https://doi.org/10.3390/pharmaceutics15041057
2. NIH. Ashwagandha: Is it helpful for stress, anxiety, or sleep?,[Online] <https://ods.od.nih.gov/factsheets/Ashwagandha-HealthProfessional/> (2023).
3. Panossian, A. G. et al. (2021). Evolution of the adaptogenic concept from traditional use to medical systems: Pharmacology of stress- and aging-related diseases. Med Res Rev 41, 630-703. https://doi.org/10.1002/med.21743
4. 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 34, 255-262. https://doi.org/10.4103/0253-7176.106022
5. Pandit, S. et al. (2024). Effects of Withania somnifera Extract in Chronically Stressed Adults: A Randomized Controlled Trial. Nutrients 16. https://doi.org/10.3390/nu16091293
6. Salve, J., et al. (2019). Adaptogenic and Anxiolytic Effects of Ashwagandha Root Extract in Healthy Adults: A Double-blind, Randomized, Placebo-controlled Clinical Study. Cureus 11, e6466. https://doi.org/10.7759/cureus.6466
7. Chengappa, K. N. et al. (2013). Randomized placebo-controlled adjunctive study of an extract of withania somnifera for cognitive dysfunction in bipolar disorder. J Clin Psychiatry 74, 1076-1083. https://doi.org/10.4088/JCP.13m08413
8. Bhattacharya, S. K., et al. (2000). Anxiolytic-antidepressant activity of Withania somnifera glycowithanolides: an experimental study. Phytomedicine 7, 463-469. https://doi.org/10.1016/S0944-7113(00)80030-6
9. Tharakan, A. et al. (2021). Immunomodulatory Effect of Withania somnifera (Ashwagandha) Extract-A Randomized, Double-Blind, Placebo Controlled Trial with an Open Label Extension on Healthy Participants. J Clin Med 10. https://doi.org/10.3390/jcm10163644
10. Wankhede, S., et al. (2015). Examining the effect of Withania somnifera supplementation on muscle strength and recovery: a randomized controlled trial. J Int Soc Sports Nutr 12, 43. https://doi.org/10.1186/s12970-015-0104-9
11. Ziegenfuss, T. N. et al. (2018). Effects of an Aqueous Extract of Withania somnifera on Strength Training Adaptations and Recovery: The STAR Trial. Nutrients 10. https://doi.org/10.3390/nu10111807
12. Shenoy, S., et al. (2012) Effects of eight-week supplementation of Ashwagandha on cardiorespiratory endurance in elite Indian cyclists.. J Ayurveda Integr Med 3, 209-214. https://doi.org/10.4103/0975-9476.104444

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