Herbal supplements 1 - Ashwagandha

Herbal supplements 1 - Ashwagandha

The wide variety of herbal supplements will confuse. This series of posts looks at the evidence for common recommendations.

Ashwagandha for sleep, cognition and anxiety

The areas of potential use: sleep, stress, anxiety. Possibly to aid cognition in over 50’s

How does it work?

Probably via GABA-ergic pathways and/ or suppressing ACTH and thus cortisol levels. GABA, is an inhibitory neurotransmitter that reduces overall brain signal levels. Studies in rodents show increased GABA activity in the central nervous system (CNS) and deeper sleep by promoting delta waves and increasing non-REM sleep duration [1].

For stress and anxiety Human Studies show a potential cortisol-lowering effect.

A 60-day, randomized, double-blind, placebo-controlled study investigated the stress-relieving and pharmacological activity of an ashwagandha extract [240 mg of a standardized ashwagandha extract (Shoden) once daily ] in stressed, healthy adults [2]

There was a 40% reduction in morning cortisol after 60 days of use and a significant reduction in the Hamilton Anxiety scale.

For Sleep, what is the data?

A Meta-Analysis on Sleep Benefits reviewed five RCTs (double-blinded, placebo-controlled) [3]. There were modest effects on overall sleep duration.

Evaluating this: the Ashwagandha studies cover a variety of products that are not truly comparable. None of the studies has looked at the range of effective doses. There are 8 major ‘withanolides’, but plant extracts include around 900 compounds in this group although most are in small quantities[4]. The extracts used come either solely from the root of the plant [high in withanolides] or include the leaves [with several other compounds potentially dominating], which is another confounding factor.

The best standardisation we can achieve is to look at the declared content of withanolides [ie the 8 usually assayed] and confirm that independent laboratories agree that this is the content. Consumer labs do that process for you [Consumer Lab Testing Report].

They recommend 3 products: Herb Pharm® Ashwagandha - Alcohol free extract, Nature's Way® Ashwagandha capsules and NOW® Ashwagandha, a tablet. Dose is one of each 3 times daily. This corresponds to a daily withanolide dose of 52 mg for Natures Way; 71 mg for Herb Pharm drops and 35 mg for NOW. These are all in a similar range but absorption and individual variation has not been tested.

Cognition

The data is thin but there are RCTs. One study in 50 patients with MCI showed improvements in memory and executive function after 8 weeks [5]. A recent study investigated a new formulation not yet commercially available in 40 patients for 60 days against placebo with positive results [6]. These are short durations and small numbers so suggest an effect but are not compelling data.

Should you use it?

There are no established hazards and modest evidence of efficacy: at the doses above it is worth a try to help sleep or anxiety or cognitive difficulty.

The review articles point out that it is probably necessary to take the product for 3 months in order to truly check for an effect.

In respect of sleep - this is not a ‘sleeping pill. Dealing with sleep problems requires attention to all the sleep hygiene issues covered in other blog posts eg temperature, which is the most important, light, noise, phone use etc. Setting your circadian rhythm with melatonin is equally important as an intervention for poor sleep.

Trying Ashwagandha is a first step alternative to prescription drugs like SSRIs or benzodiazepines for anxiety or conventional sleeping tablets for insomnia.

---

[1] Park CW, Hong KB, Suh HJ, Ahn Y. Sleep-promoting activity of amylase-treated Ashwagandha (Withania somnifera L. Dunal) root extract via GABA receptors. J Food Drug Anal. 2023 Jun 15;31(2):278-288. doi: 10.38212/2224-6614.3456. PMID: 37335157; PMCID: PMC10281725.

[2] Lopresti, Adrian L.. An investigation into the stress-relieving and pharmacological actions of an ashwagandha (Withania somnifera) extract: A randomized, double-blind, placebo-controlled study. Medicine 98(37):p e17186, September 2019. | DOI: 10.1097/MD.0000000000017186

[3] Cheah KL, Norhayati MN, Husniati Yaacob L, Abdul Rahman R. Effect of Ashwagandha (Withania somnifera) extract on sleep: A systematic review and meta-analysis. PLoS One. 2021 Sep 24;16(9):e0257843. doi: 10.1371/journal.pone.0257843. PMID: 34559859; PMCID: PMC8462692.

[4] White PT, Subramanian C, Motiwala HF, Cohen MS. Natural Withanolides in the Treatment of Chronic Diseases. Adv Exp Med Biol. 2016;928:329-373. doi: 10.1007/978-3-319-41334-1_14. PMID: 27671823; PMCID: PMC7121644.

[5] Choudhary D, Bhattacharyya S, Bose S. Efficacy and Safety of Ashwagandha (Withania somnifera (L.) Dunal) Root Extract in Improving Memory and Cognitive Functions. J Diet Suppl. 2017 Nov 2;14(6):599-612. doi: 10.1080/19390211.2017.1284970. Epub 2017 Feb 21. PMID: 28471731.

[6] Rai HP, Mishra DN. Effect of ashwagandha (Withania somnifera) extract with Sominone (Somin-On™) to improve memory in adults with mild cognitive impairment: A randomized, double-blind, placebo-controlled study. J Psychopharmacol. 2025 Apr;39(4):350-363. doi: 10.1177/02698811251324377. Epub 2025 Mar 18. PMID: 40099725.