Ashwagandha Side Effects: Who Shouldn't Take It

Quick answer: Ashwagandha is generally well tolerated by healthy adults in the short term, but it isn't right for everyone. The most common side effects are stomach upset, diarrhoea and drowsiness, and rare cases of liver problems have been reported. You should avoid it if you're pregnant or breastfeeding, have a thyroid or autoimmune condition, have liver disease, or take sedatives, thyroid medicine, immunosuppressants, or medicines for diabetes or blood pressure, unless your doctor says it's okay.

What is ashwagandha?

Ashwagandha (Withania somnifera) is a shrub whose root has been used in traditional Ayurvedic practice for thousands of years. It's now one of the most popular botanicals in the UK. For dosage and forms, see our KSM-66® Calm Complex product page.

We believe being clear about who it's not for is just as important as talking about it at all.

Common side effects

• Stomach upset or nausea
• Diarrhoea
• Drowsiness
• Headache

Taking it with food can help with stomach upset. If side effects don't settle, stop taking it.

Rare but serious: the liver

There have been rare reports of liver injury linked to ashwagandha supplements. It's uncommon, but it's the reason some European regulators, including Denmark, have restricted ashwagandha products. Stop taking it and contact your GP straight away if you notice:

• Yellowing of the skin or the whites of the eyes
• Dark urine or pale stools
• Itchy skin
• Pain in the upper right side of your stomach
• Unusual tiredness or loss of appetite

Who shouldn't take ashwagandha

Pregnancy and breastfeeding

Ashwagandha should not be used during pregnancy or while breastfeeding.

Thyroid conditions

Ashwagandha may affect thyroid hormone levels. If you have an overactive or underactive thyroid, or take thyroid medication, speak to your doctor first.

Autoimmune conditions

Because it may affect the immune system, people with conditions such as rheumatoid arthritis, lupus or multiple sclerosis should check with their doctor.

Liver disease

Avoid ashwagandha if you have any existing liver condition.

Before surgery

Stop taking it at least two weeks before planned surgery, as it may interact with anaesthesia.

Possible medicine interactions

Speak to your GP or pharmacist before taking ashwagandha if you take:

• Sleeping tablets, sedatives or anti-anxiety medicines
• Thyroid medication
• Immunosuppressants
• Medicines for diabetes
• Medicines for blood pressure

Using it sensibly

• Stick to the dose on the label.
• Don't combine several ashwagandha products. Check blends too, such as our Black Seed, Shilajit & Ashwagandha Gummies.
• Take breaks: many people use it for up to three months, then pause.
• Stop if you notice side effects.

Alternatives for an evening routine

If ashwagandha isn't right for you, magnesium contributes to normal psychological function and can be part of an evening routine. See our guide to magnesium for sleep.

FAQs

Is ashwagandha safe to take every day?

Most healthy adults tolerate it well short term at label doses. Taking breaks after a few months is sensible.

Can ashwagandha damage your liver?

Rare cases of liver injury have been reported. Stop and see your GP if you notice yellowing skin or eyes, or dark urine.

Who should not take ashwagandha?

Pregnant or breastfeeding women, people with thyroid, autoimmune or liver conditions, and those on certain medicines should avoid it or check with their doctor.

Reviewed by John Lebach (Nutrition Coach) and Numan Caan (Senior Sports Scientist)

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This article is for general information only and isn't medical advice. Food supplements should not be used as a substitute for a varied, balanced diet and a healthy lifestyle. If you take prescribed medication, are pregnant or breastfeeding, speak to your GP or pharmacist before starting a supplement.