What Does Ashwagandha Do to the Body, and Is It Safe to Take?

In this guide, we’ll take a clear, evidence-based look at what Ashwagandha really does, how it affects the body, what the research says about its safety, and who should steer clear. Whether you’re considering taking it for better sleep, lower stress, or general wellbeing, here’s what you should know before trying Ashwagandha.

Ashwagandha (Withania somnifera) has been used for thousands of years in Ayurvedic medicine as a tonic for strength, resilience, and peace of mind. Today, modern research is catching up with what traditional practitioners have long believed — that this powerful root may help the body adapt to stress and restore balance in both mind and body.

Known as an adaptogen, Ashwagandha appears to support the body’s ability to manage stress, anxiety, and fatigue, helping to maintain calm and focus when life gets demanding. Scientists are now studying its effects on cortisol regulation, sleep quality, physical performance, and hormone balance, with some promising results.

What Does Ashwagandha Do to the Body?

Ashwagandha (Withania somnifera) is a traditional Ayurvedic herb that appears to help the body cope with both mental and physical stress. So what exactly does ashwagandha do? Clinical studies suggest it can help reduce anxiety, support better sleep, and lower cortisol, the hormone released when you’re under stress.

Its active compounds, known as withanolides, are thought to act on the hypothalamic–pituitary–adrenal (HPA) axis, which controls how your body responds to stress. By helping to regulate this system, Ashwagandha may bring overactive cortisol levels back into a healthy range. Laboratory research also shows it may influence GABA and serotonin pathways, which play a role in calmness and mood balance. (Chandrasekhar, K., Kapoor, J. and Anishetty, S. (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 Journal of Psychological Medicine, 34(3), pp. 255–262.)

Through a similar mechanism, ashwagandha appears to improve sleeping patterns and reduce insomnia: ‘Efficacy and Safety of Ashwagandha (Withania somnifera) Root Extract in Insomnia and Anxiety: A Double-blind, Randomized, Placebo-controlled Study’, Langade et al.

Beyond stress relief, ashwagandha has been shown to support energy levels, endurance, and recovery. Studies involving resistance training have found small but consistent improvements in muscle strength, exercise performance, and testosterone levels when taken daily for 6 to 8 weeks (Wankhede. et al. (2015). ‘Examining the effect of Withania somnifera supplementation on muscle strength and recovery: A randomized controlled trial’)

While these results are promising, researchers note that more large, independent studies are still needed. The best evidence so far supports Ashwagandha’s role in managing stress and anxiety, improving sleep, and supporting general wellbeing when taken regularly for several weeks.

Summary of What Does Ashwagandha Do?

Helps regulate the body’s stress response and lower cortisol.
May improve mood, sleep, and mental resilience.
Can modestly support strength, endurance, and recovery.
Best results occur after 6–8 weeks of consistent use.

from

Find Out More

Is Ashwagandha Safe According to the NHS and Health Authorities?

In the UK, Ashwagandha can be sold as either a food supplement or as a Traditional Herbal Medicinal Product (THR) under the MHRA’s Traditional Herbal Registration scheme. This system ensures quality and safety standards are met but does not require proof that the herb is effective, only that it has a history of traditional use.

The NHS advises people to be cautious with herbal medicines because quality and ingredient consistency can vary, and some can interact with prescription drugs. It recommends buying from trusted UK brands and reporting any side effects through the Yellow Card Scheme.

At the European level, the European Food Safety Authority (EFSA) has not approved any official health claims for Ashwagandha, as current evidence is considered insufficient. Botanicals used in food supplements are instead monitored under general food safety regulations.

In 2024, the UK Food Standards Agency (FSA) opened a call for evidence on Ashwagandha to review its safety in food supplements. This means that regulators are still assessing the long-term safety data to ensure the guidance given to the public remains accurate and up to date.

Summary of Ashwagandha Safety

Classified as a traditional herbal supplement, not a licensed medicine.
No EFSA-approved health claims to date.
Generally considered safe at typical doses (300–600 mg/day).
Long-term safety and use in pregnancy remain unconfirmed.

What Happens When You Take Ashwagandha Daily?

When Ashwagandha is taken daily for 6 to 8 weeks, clinical studies show lower stress levels and reduced cortisol, the body’s main stress hormone. People in these trials often report feeling calmer, less anxious, and sleeping better compared with those taking a placebo.

Scientists think Ashwagandha works by regulating stress-related proteins and neurotransmitters involved in mood and relaxation. These pathways are still being researched, but current evidence suggests the herb helps the body fine-tune its stress response over time — not immediately, but gradually across several weeks.

Ashwagandha has also been studied in people doing strength or resistance training, where it was linked to modest increases in muscle strength and lean mass compared with a placebo group (Journal of the International Society of Sports Nutrition, 2015).

Most studies use a standardised root extract at doses between 300 and 600 mg per day, usually divided into one or two servings. However, results can vary between different brands and extracts, so it’s important to choose a reputable supplement.

Summary of the Effects of Using Ashwagandha Daily

Gradual reductions in stress and cortisol over several weeks.
Improved sleep quality and calmness in clinical studies.
May slightly enhance physical performance and vitality.
Works best when taken regularly rather than occasionally.

from

Find Out More

What Are the Negative Side Effects of Ashwagandha?

Most people tolerate Ashwagandha well and ashwagandha is generally considered safe, but some side effects can occur, especially at higher doses. The most common are cramps, nausea or diarrhoea, and occasionally drowsiness or headaches. These effects are usually mild and tend to settle when the dose is reduced.

There have also been rare but well-documented cases of liver injury after starting Ashwagandha supplements. (Pharmaceuticals (2023). Björnsson, E.S. et al. ‘Ashwagandha-induced liver injury: a review of published case reports.’ Pharmaceuticals, 16(4), 561.) In these reports, people developed jaundice (yellowing of the skin or eyes) and abnormal liver tests, sometimes taking months to recover. A few isolated cases required hospital treatment or liver transplant, though this is extremely uncommon.

Ashwagandha may also increase thyroid hormone levels in some people. In one small clinical trial, adults with mild thyroid underactivity who took 600 mg daily for 8 weeks showed higher thyroid hormone levels — but it’s unclear if this also affects people with normal thyroid function. (Efficacy and Safety of Ashwagandha Root Extract in Subclinical Hypothyroid Patients: A Double-Blind, Randomized Placebo-Controlled Trial, Sharma et al.)

Stop taking Ashwagandha and see a doctor immediately if you notice warning signs such as yellow skin or eyes, dark urine, severe itching, extreme tiredness, or pain in the upper right side of your abdomen, as these could signal liver injury.

Summary of Negative Effects of Ashwagandha

Mild side effects can include cramps, nausea, or diarrhoea.
Rare reports link it to liver injury and thyroid changes.
Stop use if you develop jaundice, dark urine, or severe fatigue.
Seek medical advice before combining with medication.

Who Should Not Take Ashwagandha?

Ashwagandha isn’t suitable for everyone. Whilst ashwagandha safety is generally high, it should not be used during pregnancy or breastfeeding, as there isn’t enough evidence to confirm it’s safe.

The German Federal Institute for Risk Assessment (BfR) also advises against its use in children Bundesinstitut für Risikobewertung and people with liver disease (Herb-Induced Liver Injury by Ayurvedic Ashwagandha as Assessed for Causality by the Updated RUCAM: An Emerging Cause by Goran et al.) because a few medical case reports have linked Ashwagandha to liver problems, although these cases are rare.

If you have a thyroid condition, talk to your doctor before taking it — some studies suggest it can raise thyroid hormone levels, which might interfere with thyroid medication. (Efficacy and Safety of Ashwagandha Root Extract in Subclinical Hypothyroid Patients: A Double-Blind, Randomized Placebo-Controlled Trial, Sharma et al.)

Ashwagandha can also interact with certain medicines, including those that cause drowsiness, lower blood pressure or blood sugar, or affect the immune or hormonal systems. If you take any regular medication, the NHS advises checking with a doctor or pharmacist before using herbal supplements.

Summary of Who Should Not Take Ashwagandha

Avoid during pregnancy, breastfeeding, or in children.
Not suitable for people with liver disease or previous hepatitis.
People with thyroid disorders should consult a doctor first.
Check with a healthcare professional if taking any prescription drugs.

Conclusion

Ashwagandha is one of the best-studied adaptogenic herbs, with growing scientific evidence supporting its traditional use for stress reduction, improved sleep, and overall wellbeing. When taken consistently for several weeks, it may help lower cortisol, promote calmness, and modestly enhance strength and vitality.

However, it isn’t suitable for everyone, especially pregnant women, people who have thyroid or liver conditions, or take certain medications. Like all herbal supplements, it should be used with awareness and ideally under professional guidance.

With high-quality products and realistic expectations, ashwagandha can be a useful addition to a balanced lifestyle that includes good sleep, nutrition, and stress management. Ashwagandha is one of nature’s most researched adaptogens, offering calm energy and stress support when used responsibly.

Try Vitabright Organic Ashwagandha KSM-66 Capsules, the gold standard in purity and potency.

from

Find Out More

Ashwagandha: Key Takeaways

Ashwagandha is an adaptogenic herb that may help the body manage stress and lower cortisol levels.
Clinical studies suggest benefits for anxiety, sleep and a sense of well-being, with modest improvements in energy and endurance.
It’s generally well tolerated but can cause cramps, nausea, diarrhoea, or drowsiness in some people.
Avoid ashwagandha if you are pregnant, breastfeeding, or if you have liver or thyroid disease unless advised otherwise by a doctor.
Results build up gradually — most benefits appear after 6–8 weeks of regular use.