Introduction
Ashwagandha has become one of the most talked-about supplements in the wellness world and for good reason. Touted for its ability to reduce stress, enhance sleep, and support overall wellbeing, it’s often grouped into a special class of herbs called adaptogens.
But what exactly is ashwagandha? How does it work? And most importantly, what does the research actually say?
In this article, we’ll break down what ashwagandha is, how it functions as an adaptogen, the latest clinical evidence behind its effects, and how to guide clients in using it safely and effectively.
What Is Ashwagandha?
Ahwagandha (Withania somnifera) is a small shrub native to India and North Africa. Its roots and leaves have been used for over 3,000 years in Ayurvedic medicine, primarily to help the body manage stress, restore energy, and improve vitality.
Ashwagandha belongs to a category of natural substances known as adaptogens – herbs that help the body adapt to stress and rebalance physiological systems during periods of mental or physical strain.
According to Panossian and Wilkes (2010), adaptogens are believed to:
Reduce anxiety (anxiolytic effect)
Combat fatigue
Support cognitive function and resilience
Enhance overall stress response without being habit-forming or sedative
Ashwagandha is one of the most well-known and well-researched adaptogens, and its growing popularity in both sports and general wellness circles is due in part to its accessibility, tolerability, and emerging scientific support.
How Does Ashwagandha Work?
At its core, Ashwagandha is believed to support the body’s ability to maintain homeostasis, the internal balance of physiological systems, especially during periods of heightened stress.
It’s thought to do this by modulating systems involved in the stress response, particularly the hypothalamic-pituitary-adrenal (HPA) axis and the release of cortisol, the body’s primary stress hormone. When stress is prolonged or poorly managed, cortisol levels can remain elevated, disrupting sleep, mood, energy, and even fat metabolism.
Ashwagandha may help counteract this by:
Reducing cortisol production, especially in chronically stressed individuals
Improving resilience to physical and emotional stressors
Promoting calmness without acting as a sedative
It also appears to have mild effects on the nervous system, contributing to its calming and anxiolytic properties. This is why it’s increasingly used to support clients dealing with high stress, poor sleep, or low recovery capacity, particularly those in high-demand roles or training environments.
Study Spotlight: Salve et al. (2019)
One of the most cited clinical trials investigating Ashwagandha’s effectiveness is the study titled “Adaptogenic and Anxiolytic Effects of Ashwagandha Root Extract in Healthy Adults” by Salve, Pate, Debnath, and Langade.
It’s a well-structured, 8-week study that ticks all the boxes for research quality:
Key study features:
Randomised: Participants were assigned to groups without bias
Double-blind: Neither participants nor researchers knew who got the real supplement
Placebo-controlled: Effects were compared against a placebo group
Dose-response: Two different doses of Ashwagandha were tested, 250 mg and 600 mg per day
Participants included 60 “stressed” but otherwise healthy adults, aged 18–55. To be included, they had to score ≥20 on the Perceived Stress Scale (PSS), a validated tool that assesses subjective stress across 10 items.
This made the cohort highly relevant for real-world coaching: everyday adults under ongoing stress, but not clinically unwell.
Each participant was given capsules (identical in appearance) for 8 weeks:
Group 1: 250 mg Ashwagandha per day
Group 2: 600 mg Ashwagandha per day
Group 3: 250 mg of starch (placebo) per day
The study aimed to measure changes in stress, anxiety, cortisol levels, and sleep quality, all highly relevant outcomes for both wellness and performance-focused clients.
What Did the Study Find?
The results from Salve et al. (2019) painted a consistent picture: Ashwagandha, especially at the higher dose, had a measurable, beneficial impact on stress-related outcomes. Here’s how it broke down:
🧠 Stress (Perceived Stress Scale)
All groups, including the placebo, saw reduced stress scores (a common finding in trials due to expectancy effects).
However, both Ashwagandha groups (250 mg and 600 mg) saw greater reductions in stress than placebo.
The 600 mg group had the most significant improvement, suggesting a dose-response relationship.
🧪 Cortisol Levels
Cortisol, the body’s primary stress hormone, remained largely unchanged in the placebo group.
Both Ashwagandha groups experienced a statistically significant drop in cortisol, with the 600 mg group again showing the greatest reduction.
This supports Ashwagandha’s role in modulating the physiological stress response, not just perceived stress.
😰 Anxiety (Hamilton Anxiety Scale)
All groups reported some improvement, but only the 600 mg group saw a significant reduction in anxiety when compared to baseline and placebo.
This suggests a threshold effect, where lower doses may not provide enough of a benefit for anxiety symptoms.
😴 Sleep Quality
Both Ashwagandha groups experienced improvements in sleep quality, with significant differences compared to placebo.
This supports anecdotal reports of better sleep in those supplementing with Ashwagandha, likely linked to reduced cortisol and anxiety.
Overall takeaway:
600 mg/day appears to be the most effective dose for improving stress, anxiety, cortisol, and sleep in otherwise healthy but stressed adults.
Is Ashwagandha Safe?
In clinical trials, including the one by Salve et al. (2019), Ashwagandha has generally been well tolerated, with minimal side effects reported.
The most commonly mentioned side effect is mild drowsiness, which may explain its positive impact on sleep quality. No serious adverse events were reported in the study, and no participants dropped out due to side effects.
That said, here’s what coaches should keep in mind when advising clients:
Long-term safety data is still limited, especially beyond 8–12 weeks of continuous use.
Because Ashwagandha may influence neurotransmission and hormone levels (like cortisol and potentially testosterone), caution is advised with high doses or long-term use without breaks.
It’s also best to avoid in clients who are pregnant, breastfeeding, or on thyroid or sedative medications, unless cleared by a healthcare provider.
While early evidence suggests Ashwagandha is safe for most people, always encourage clients to consult their GP or a registered dietician before beginning any supplement protocol.
How to Take Ashwagandha
Dosing recommendations for Ashwagandha vary slightly depending on the goal, but current evidence, especially from the Salve et al. (2019) study, points to 600 mg per day as the most effective dose for stress, anxiety, and sleep improvements.
General usage:
Standard dose: 600 mg/day, split into two doses of 300 mg
One with breakfast
One with dinner
Lower dose (250–300 mg/day): May offer mild benefits, especially for sleep
Higher doses (600–1,000 mg/day): Sometimes used in athletic populations or during high-stress periods, but more research is needed on long-term safety
⚠️ Things to consider:
Cycle the supplement: Because long-term effects are not fully known, some practitioners recommend taking breaks (e.g., 4 weeks on, 1 week off)
Avoid stacking with other adaptogens without professional input, especially those that also affect cortisol or neurotransmitters
Choose a high-quality extract, ideally one standardised to withanolides (the active compounds)
In practice, keeping things simple and consistent, 600 mg/day split across two meals, is a safe and effective recommendation for most clients looking to reduce stress and improve sleep quality.
Conclusion
Ashwagandha is more than just a trendy supplement, it’s a time-tested adaptogen with growing scientific support for its ability to reduce stress, regulate cortisol, improve sleep, and ease anxiety.
The Salve et al. (2019) study shows that 600 mg per day of Ashwagandha root extract can meaningfully reduce stress and cortisol, improve sleep quality, and even lower anxiety levels in healthy but stressed adults. Lower doses (250 mg/day) may offer some benefits, particularly for sleep, but the 600 mg dose remains the most consistently effective in current research.
Key takeaways for coaches:
Ashwagandha works best when used consistently over 6–8 weeks
A standard dose of 600 mg/day (split into AM/PM) is both effective and well tolerated
It’s safe for most people short-term, but long-term use should be discussed with a healthcare professional
Focus on education, not hype, clients need clear, realistic expectations and guidance around supplement use
Used wisely, Ashwagandha can be a valuable tool in a coach’s kit, especially for clients managing stress, struggling with sleep, or looking to support recovery in high-pressure environments.
