Ashwagandha and stress relief: can it really lower cortisol

What the research shows about ashwagandha and cortisol

Cortisol is the primary stress hormone. Chronic elevation drives anxiety, sleep disruption, abdominal weight gain, immune suppression and impaired testosterone production. Ashwagandha's central mechanism is cortisol reduction and this is supported by more high-quality evidence than any other claim about the supplement. Here is what the trials show.

1. Cortisol reductions of 14 to 28 percent are documented

The Salve 2019 trial (PMC6979308) randomised 60 stressed adults to 125 mg, 300 mg twice daily (600 mg/day) or placebo for 8 weeks. Serum cortisol reduced 14.5 percent at 250 mg/day and 27.9 percent at 600 mg/day versus placebo. The Chandrasekhar 2012 foundational trial showed similar effects. The 2025 meta-analysis (PMC12242034) across 7 cortisol trials confirmed significant pooled effects (mu = -2.36, p less than 0.0001). This is robust evidence.

2. Perceived stress reductions are equally well documented

The same trials measured the Perceived Stress Scale (PSS) at baseline and study end. The Salve 2019 trial found PSS reductions at 250 mg/day (p less than 0.05) and 600 mg/day (p less than 0.001). The 2025 meta-analysis pooled PSS effects across 6 trials and found significant reduction (mu = -4.88, 95 percent CI -7.84 to -1.91, p = 0.0013). Both the objective biomarker (cortisol) and the subjective experience (PSS) move in the same direction.

3. The mechanism is HPA axis modulation

The hypothalamic-pituitary-adrenal (HPA) axis controls cortisol release. Withanolides appear to suppress corticotropin-releasing hormone (CRH) from the hypothalamus and enhance glucocorticoid receptor sensitivity. The end result is more efficient negative feedback on cortisol production. In practice this means the body releases less cortisol in response to ongoing stress and the cortisol that is released is cleared more efficiently.

4. The effect builds over weeks, not days

Ashwagandha does not work like a sedative. There is no acute calming effect within an hour of a dose comparable to a benzodiazepine. The cortisol-lowering effect builds through continuous daily dosing as the HPA axis gradually rebalances. Most clinical trials measure significant cortisol reduction at 8 weeks. Smaller effects emerge at 4 to 6 weeks. Anyone expecting same-day stress relief will be disappointed.

5. People with high baseline cortisol see the biggest changes

Ashwagandha appears to normalise cortisol toward healthy levels rather than driving cortisol below normal. People with already-normal cortisol levels see smaller effects. People with high baseline cortisol from chronic stress, sleep deprivation or shift work see larger effects. This is consistent with the supplement's adaptogenic profile: it nudges dysregulated systems toward normal rather than driving them in one direction regardless of starting point.

How to use ashwagandha for stress effectively in five steps

If your main goal is stress reduction or cortisol normalisation, this protocol matches the trials that produced significant cortisol and PSS reductions. The single biggest reason people say it did not work is quitting too early.

Step 1. Measure your baseline before you start

Use the Perceived Stress Scale (PSS-10, freely available online) and record your score. Also rate your subjective stress on a 1 to 10 scale, sleep quality on a 1 to 10 scale and morning anxiety on a 1 to 10 scale. These are your baselines for measuring change at week 8. Subjective recall of how stressed you felt 8 weeks ago is unreliable so written baselines matter.

Step 2. Use 300 mg twice daily with meals

The Salve 2019 trial used 300 mg twice daily totalling 600 mg per day for 8 weeks at this protocol. Look for KSM-66 or Sensoril branded extracts at minimum 2.5 percent withanolides. Take morning dose with breakfast and evening dose with dinner. Both meals should contain some fat for withanolide absorption.

Step 3. Address sleep alongside the supplement

Sleep deprivation drives cortisol elevation which is the same problem ashwagandha is trying to fix. Sleep 7 to 9 hours nightly. Limit caffeine after midday. Reduce alcohol because it fragments sleep. Limit screens 60 minutes before bed. The supplement amplifies good sleep hygiene rather than compensating for poor sleep.

Step 4. Reduce other cortisol drivers

Excessive caffeine intake elevates cortisol acutely and may sensitise the HPA axis over time. Limit to 200 mg per day (about 2 cups of coffee). Alcohol elevates cortisol particularly in the recovery phase. Limit per CMO guidance to 14 units per week with multiple alcohol-free days. Overtraining elevates cortisol persistently. Schedule rest days in any exercise programme.

Step 5. Reassess at week 8 against baseline

Complete the PSS-10 again at week 8 and compare scores. A reduction of 5 points or more is clinically meaningful. Also reassess your 1 to 10 stress, sleep and anxiety ratings. If you see meaningful improvement, continue. If not, the supplement may not be the answer for your situation. See your GP if stress is significantly affecting your daily life. The NHS provides free talking therapies via self-referral including cognitive behavioural therapy.

For anyone running an 8-week cortisol reduction protocol, our Ashwagandha Gummies deliver the same standardised root extract dose used in the clinical stress trials. Same active ingredient. Same daily dose. Much easier to take consistently every day than capsules or measured powders.

When ashwagandha is a problem

Ashwagandha at standard doses is generally well tolerated for stress reduction. The UK Food Standards Agency is currently reviewing ashwagandha food supplements. Stop the supplement and see your GP if any of the following apply.

• Severe or worsening stress, anxiety or depression despite consistent supplement use. This needs proper medical assessment.
• Suicidal thoughts or thoughts of self-harm. Contact your GP urgently or call 111 for advice. The Samaritans are available 24 hours on 116 123.
• Yellowing of skin or eyes, dark urine or right upper abdominal pain. These can signal liver injury which has been reported rarely (LiverTox 2024).
• Symptoms of thyroid overactivity including palpitations, tremor, heat intolerance or unexplained weight loss. Ashwagandha can raise thyroid hormone levels which can itself cause anxiety symptoms.
• Taking SSRIs, benzodiazepines or other prescribed anxiety medication without telling your GP.

Anyone with clinically significant stress or anxiety should access proper care. NICE guidance recommends cognitive behavioural therapy as first-line treatment for generalised anxiety disorder. The NHS provides free CBT via self-referral in most regions. The supplement should not delay access to evidence-based care for serious mental health symptoms.

More on ashwagandha and stress

Stress effects connect to several other guides. Ashwagandha for anxiety and mood balance covers the anxiety evidence specifically. How long does ashwagandha take to work for anxiety covers the timeline. And does ashwagandha work covers the broader evidence picture.