Ashwagandha: Sleep, Stress, & Testosterone

Ashwagandha is a small woody evergreen shrub credited with improvements to anxiety, depression, sleep, testosterone, immune health, inflammation, and others. As an adaptogen—something that helps the body adapt to and relieve stress—its role is multifactorial in the brain via GABA receptors, the hypothalamic-pituitary-adrenal (HPA) axis, and the hypothalamic-pituitary-gonadal (HPG) axis.

In this article, I’m going to review the following:

• Ashwagandha’s structure, why the plant’s different compounds matter, and how this ties back to supplement selection.

• Its mechanistic roles with GABA receptors, the HPA and HPG axes, cortisol, and testosterone.

• Effective doses and timelines to improve sleep, stress, anxiety, and testosterone.

Ashwagandha’s Structure and its Various Compounds

Ashwagandha’s scientific name is Withania somnifera (WS), which I’ll use moving forward for brevity’s sake, WS translates to sleep inducer, but also goes by the names Indian ginseng and Indian winter cherry, among others. (1)

Often, we think of a supplement or micronutrient simply as one unit. For instance, the benefits of creatine supplementation are because of the creatine molecule. WS differs, as it’s a plant with various parts, containing different compounds, that may produce different effects. Given the variety of compounds available throughout the plant, this may be why WS research can produce varying results, apart from comparing different doses, timelines, and other factors of research design.

For instance, WS contains the following compounds across various locations:

Wiciński et al. (2023) (1)

Both the withanolides, of the steroidal lactones, and phenolic compounds of the root are believed to be where most health benefits are derived from. (1) Root extracts were the most common WS derivatives used across studies I reviewed for this article.

Notice on certain supplement labels the location of the extract and its percentage of compound standardization are listed. For instance, Momentous Ashwagandha lists one capsule as containing 300 mg WS, extracted from the root and leaf, and standardized to 3.5% withanolides.

Mechanisms: GABA Receptors, HPG and HPA Axes, Cortisol, and Testosterone

Anytime you read about the benefits of X on Y as an outcome, it’s important to understand the mechanism—the why behind how something works. This helps us understand if there’s a correlation (when A increases, B happens to as well, whether through a relationship or a coincidence) or a causation (when I consume C it results in D happening).

Again, given WS is multifactorial in its physical plant structure and compounds located throughout that structure, WS’s range seems to affect different pathways throughout the body.

GABA Receptors

Gamma-aminobutyric acid (GABA) is a neurotransmitter interacting with several GABA receptors (A, B, and C). The focus of WS is specifically on GABA receptor A (a.k.a., GABAA, GABA-A). (2) By binding to GABA-A, WS mimics the GABA neurotransmitter that acts as an inhibitor within the central nervous system, resulting in a slowing of certain brain functions, and the person experiencing a sense of calmness, reduction in stress and anxiety, and potentially improving one’s sleep. (3-5)

This makes sense, as GABA agonists and GABA-A receptors are targets within the pharmaceutical industry to relieve anxiety. For instance, the Benzodiazepines (e.g., Lorazepam, Diazepam) and muscle relaxants bind to GABA-A (as does alcohol!). (6)

Lorazepam. (Yahoo Entertainment, 2025)

HPA and HPG Axes

The HPA axis is a messaging system originating in the brainstem at the hypothalamus that communicates like a game of telephone: first to the brainstem’s pituitary gland and onward to the adrenal glands.

The HPG axis swaps the adrenal (A) for the gonadal (G), meaning this axis influences the gonads—the ovaries and testes.

Luteinising hormone (LH) exists in both men and women and is produced in the pituitary gland. In men, LH targets the testes to stimulate testosterone production. (7) Stress is hypothesized as reducing LH pulse frequency and its effects on the testes, thereby reducing testosterone production. (8)

The adrenal glands are two organs, each sitting atop the kidneys. Cortisol is a hormone produced in the outer cortex of the adrenal glands, with cortisol increasing when a person experiences stress, including intensive athletic training or overtraining.

The adrenal glands also produce the steroid hormone DHEA, which ultimately converts into estrogen and testosterone. Depression, anxiety disorders, and/or increased stress are all associated with increases in DHEA and cortisol. (1)

Thus, the HPA and HPG axes interact, as cortisol, stress, LH, testosterone, and DHEA are all intertwined.

Although Sprengle et al. (2025) highlighted how withaferin A (of the withanolide compound family) is hypothesized to positively influence stress and cortisol levels, the mechanism of WS’s is not fully understood. (9-10) However, WS is thought to influence the HPA axis.

Wicinksi et al. (2023) (1)

Purported Effects and Their Doses

Throughout, I may reference BID, meaning twice daily. If a supplement is listed as 100 mg BID, this means the daily dose was 200 mg (100 mg x 2). TID refers to three times per day.

Sleep

Studies have been done in adults with and without sleep issues, with benefits to both populations in sleep outcomes when supplementing with WS. The effect is tied back to the HPA axis and possibly GABA-A, helping to calm the system and allowing the person can relax and fall asleep.

For those without sleep issues, Kelgane et al. (2020) provided adults aged 60-85 years old with 300 mg BID WS for 12 weeks and found that sleep quality significantly improved (p<0.0001) when compared to a placebo group. The supplement was a root extract without the percentage of withanolides defined. Sleep quality was self-reported and evaluated by how the person felt in the morning upon waking. (11)

Deshpande et al. (2020) assessed 150 adults aged 18-65 years old who were experiencing non-restorative sleep. The treatment group consumed 120 mg once daily for six weeks. The supplement was a leaf and root extract containing 21 mg withanolide glycosides. Self-reported sleep was significantly improved for the treatment group (p<0.001) with sleep actigraphy data also showing significant improvements. (12)

Langade et al. (2021) evaluated healthy adults alongside those with insomnia. Participants ranged in age from 18-50 years. Eighty participants were split into four groups: 20 healthy taking WS, 20 healthy taking placebo, 20 insomnia taking WS, and 20 insomnia taking placebo. For those consuming WS, the daily dose was 300 mg BID, consumed with milk or water, across an 8-week timespan. The supplement was a root extract standardized to >5% withanolides. In both supplemental groups, sleep quality significantly improved (p<0.0001). (13)

Stress and/or Anxiety

When evaluating stress, a biomarker used is serum cortisol. Cortisol levels fluctuate throughout the day and follows a circadian rhythm. In a healthy human, levels are highest in the morning and decline thereafter. However, levels can remain high and lose their diurnal variation in, for instance, those chronically underfueling, athletes who are overtraining or experiencing poor chronic recovery, or those experiencing high levels of chronic stress, regardless of its source. (7) Knowing this, ensure studies evaluating WS’s effect list their morning collection of serum cortisol.

Della Porta et al. (2023) conducted a systematic review on WS’s effectiveness in reducing cortisol in stressed humans. Across nine studies, seven of them showed reductions in morning serum cortisol levels, ranging from 11-32.63%. The effective total dose ranged from 125-300 mg BID and were consumed across 4-13 weeks. Leaf and/or root extracts were standardized to >3.5% withanolides. (10)

Salve et al. (2019) evaluated 18-55 year olds with Perceived Stress Scales (PSS) greater than 20, meaning at baseline participants reported moderate-to-high perceived stress levels. Participants were split into three groups: placebo, 125 mg BID WS, or 300 mg BID WS. The treatment lasted eight weeks. The WS was a root extract, but the percentage of withanolides was not listed. Compared to placebo, both dosing groups experienced significant improvements with reduced PSS scores and serum cortisol levels. The higher daily dose of 300 mg BID significantly outperformed the lower dose for both metrics. (14)

Lastly, Lopresti et al. (2019a) assessed 60 mildly anxious adults, but otherwise healthy. The treatment group was provided with 240 mg WS per day for 60 days. The supplement was an ethanol:water extract (70:30) standardized to 35% withanolide glycosides. The treatment group experienced reductions in anxiety (p=0.04 HAM-A questionnaire), morning cortisol (p<0.001), and DHEA-S (p<0.004). Testosterone increased in men compared to placebo, but not significantly. (15)

Testosterone

Lastly, WS’s purported improvement in testosterone circles back to reducing stress levels, in turn optimizing LH’s effect on the testes in stimulating testosterone production.

Compared to a fertile group of males consuming a placebo, Mahdi et al. (2011) reported increases in LH and testosterone in men with unexplained infertility, plus decreased stress levels and serum cortisol, when provided with 5 grams daily for three months (note the much higher dose used in this study compared to stress, anxiety, and sleep as outcomes). The WS was a root powder with undefined withanolide content. (8)

Smith et al. (2020) conducted a systematic review on various herbs and their effect on testosterone in men, including WS. Four studies were included, with only one showing no significant effect from supplementation (the Lopresti 2019a paper described previously). (16) The effective doses and duration of daily intake were:

• Ambiye et al. (2013): 225mg TID, root extract standardized to 5% withanolides for 90 days. (17)

• Lopresti et al. (2019b): 21 mg/day, leaf and root extract standardized to 35% withanolide glycosides for 16 weeks. (18)

• Wankhede et al. (2015): 300 mg BID, root extract standardized to 5% withanolides for 8 weeks. (19)

Thus, for testosterone improvements, the daily dose seems to be upwards of 600 mg.

Take-home Messages

Most often the athletes who ask me about WS tie their reasoning back to reducing stress and/or legally increasing their testosterone levels. Remember: High stress, means more cortisol, which affects luteinising hormone, and ultimately reduces testosterone production. The conversation with the athlete must expand to where the chronic stress is coming from. WS seems to help with stress and testosterone, plus anxiety and sleep, but the athlete needs to focus on reducing the initial stress, too.

References

1. Wiciński, M., Fajkiel-Madajczyk, A., Kurant, Z., Kurant, D., Gryczka, K., … & Zabrzyński, J. (2023). Can Ashwagandha benefit the endocrine system?—A review. Int J Mol Sci,24(22):16513 https://pubmed.ncbi.nlm.nih.gov/38003702/

2.Mihic, S.J., & Harris, R.A. (1997). GABA and GABAA receptor. Alcohol Health Res World,21(2):127-131. https://pmc.ncbi.nlm.nih.gov/articles/PMC6826832/

3.Murthy, S.V., Fathima, S.N., & Mote, R. (2022). Hydroalcoholic extract of Ashwagandha improves sleep by modulating GABA/histamine receptors and EEG slow-wave pattern in In Vitro - In Vivo experimental models. Prev Nutr Food Sci,27(1):108-120. https://pmc.ncbi.nlm.nih.gov/articles/PMC9007714/

4.Park, C.W., Hong, K.-B., Suh, H.J., & Ahn, Y. (2023). Sleep-producing activity of amylase-treated Ashwagandha (Withania somnifera L. Dunal) root extract via GABA receptors. J Food Drug Anal,31(2):278-288. https://pubmed.ncbi.nlm.nih.gov/37335157/

5.Cleveland Clinic. (2022, April 25). Gamma-aminobutyric acid (GABA). https://my.clevelandclinic.org/health/articles/22857-gamma-aminobutyric-acid-gaba 

6.Chen, R.J., & Sharma, S. (2025, February 18). GABA receptor. StatPearls [Internet]. https://www.ncbi.nlm.nih.gov/books/NBK526124/

7.Keay, N. (2022). Hormones, health and human potential: A guide to understanding your hormones to optimise your health and performance. Sequoia Books.

8.Mahdi, A.A., Shukla, K.K., Ahmad, M.K., Rajender, S., Shankhwar, S.N., … & Dalela, D. (2011). Withania somnifera improves semen quality in stress-related male fertility. Evid Based Complement Alternat Med,2011(1):1-9. https://pmc.ncbi.nlm.nih.gov/articles/PMC3136684/

9.Sprengle, M., Laskowski, R., & Jost, Z. (2025). Withania somnifera (Ashwagandha) supplementation: a review of its mechanisms, health benefits, and role in sports performance. Nutr Metab (Lond),22(1):9. https://pubmed.ncbi.nlm.nih.gov/39910586/

10.Della Porta, M., Maier, J.A., & Cazzola, R. (2023). Effects of Withania somnifera on cortisol levels in stressed human subjects: a systematic review. Nutrients,15(24):5015. https://pubmed.ncbi.nlm.nih.gov/38140274/

11.Kelgane, S.B., Salve, J., Sampara, P., & Debnath, K. (2020). Efficacy and tolerability of Ashwagandha root extract in the elderly for improvement of general well-being and sleep: a prospective, randomized, double-blind, placebo-controlled study. Cureus,12(2):e7083. https://pmc.ncbi.nlm.nih.gov/articles/PMC7096075/

12.Deshpande, A., Irani, N., Balkrishnan, R., & Benny, I.R. (2020). A randomized, double blind, placebo controlled study to evaluate the effects of ashwagandha (Withania somnifera) extract on sleep quality in healthy adults. Sleep Med,72:28-36. https://pubmed.ncbi.nlm.nih.gov/32540634/

13.Langade, D., Thakare, V., Kanchi, S., & Kelgane, S. (2021). 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. J Ethnopharmacol,10:264. https://pubmed.ncbi.nlm.nih.gov/32818573/

14.Salve, J., Pate, S., Debnath, K., & Langade, D. (2019). Adaptogenic and anxiolytic effects of Ashwagandha root extract in healthy adults: a double-blind, randomized, placebo-controlled clinical study. Cureus,11(12):e6466. https://pubmed.ncbi.nlm.nih.gov/32021735/

15. Lopresti, A.L., Smith, S.S., Malvi, H., & Kodgule, R. (2019a). An investigation into the stress-relieving and pharmacological actions of an ashwagandha (Withania somnifera) extract. Medicine (Baltimore),98(37):e17186. https://pmc.ncbi.nlm.nih.gov/articles/PMC6750292/

16. Smith, S.J., Lopresti, A.L., Teo, S.Y.M., & Fairchild, T.J. (2020). Examining the effects of herbs on testosterone concentrations in men: a systematic review. Adv Nutr,12(3):744-765. https://pubmed.ncbi.nlm.nih.gov/33150931/

17.Ambiye, V.R., Langade, D., Dongre, S., Aptikar, P., Kulkarni, M., & Dongre, A. (2013). Clinical evaluation of the spermatogenic activity of the root extract of Ashwagandha (Withania somnifera) in oligospermic men: a pilot study. Evid Based Complement Alternat Med,2013:571420. https://pubmed.ncbi.nlm.nih.gov/24371462/

18.Lopresti, A.L., Drummond, P.D., & Smith, S.J. (2019). A randomized, double-blind, placebo-controlled, crossover study examining the hormonal and vitality effects of Ashwagandha (Withania somnifera) in aging, overweight males. Am J Mens Health,12(2):1557988319835985. https://pubmed.ncbi.nlm.nih.gov/30854916/

19. Wankhede, S., Langade, D., Joshi, K., Sinha, S.R., & Bhattacharyya. (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://pubmed.ncbi.nlm.nih.gov/26609282/