Ashwagandha for Sleep: Does It Work and Is It Safe in the UK?

With increasing stress, screen time, and sleep disruptions, many people in the UK are turning to natural remedies to improve their rest. Among the most popular is ashwagandha, an ancient adaptogenic herb used in Ayurvedic medicine for centuries. From health influencers to herbal supplement brands, ashwagandha is being touted as a natural sleep aid with benefits ranging from reduced anxiety to better sleep quality. But does the science support the claims? And more importantly, is it safe and legal to use ashwagandha for sleep in the UK?

Let’s explore what ashwagandha is, how it affects sleep, and what UK consumers should know before trying it.

What Is Ashwagandha?

Ashwagandha (Withania somnifera), also known as Indian ginseng or winter cherry, is a small shrub native to India, the Middle East, and parts of Africa. The root and leaves of the plant are used to make supplements that claim to help with everything from reducing stress to improving memory, muscle strength, and fertility.

As an adaptogen, ashwagandha helps the body adapt to stress by regulating systems such as the hypothalamic-pituitary-adrenal (HPA) axis. This adaptogenic quality is one of the key reasons it’s linked to better sleep: by calming the stress response, it may help reduce the biological disruptions that interfere with rest.

While it’s not a sedative in the traditional sense, many people report feeling calmer and sleeping more deeply when taking ashwagandha regularly.

How Ashwagandha May Help With Sleep

Cortisol Reduction

Cortisol, often referred to as the “stress hormone,” follows a natural diurnal rhythm—highest in the morning and lowest at night. Chronic stress, anxiety, and poor lifestyle habits can cause elevated evening cortisol levels, which interfere with falling and staying asleep.

Ashwagandha has been shown in several studies to lower cortisol levels. A 2019 randomised, double-blind, placebo-controlled study published in Medicine (Baltimore) found that adults taking 240 mg of ashwagandha extract daily for eight weeks had significantly lower cortisol levels and improved self-reported stress and sleep quality.

Another study in PLOS One (2020) involving 80 participants found that those who took 600 mg of ashwagandha extract daily experienced better sleep quality and reduced insomnia compared to the placebo group.

Sleep Latency and Quality

Ashwagandha may improve sleep onset latency (how quickly one falls asleep) and overall sleep efficiency. In a 2021 review published in Cureus, researchers concluded that ashwagandha root extract significantly improved sleep parameters across multiple trials, particularly in people with insomnia and anxiety-related disorders.

Researchers speculate that the triethylene glycol naturally present in ashwagandha roots may contribute to sleep induction, although the exact mechanisms are still being studied.

Notably, ashwagandha doesn't produce a knockout effect like pharmaceutical sleep aids. Instead, it appears to gently support the body’s natural rhythms, particularly when used consistently over time.

Ashwagandha vs Melatonin or Magnesium

Melatonin and magnesium are also widely used sleep aids, but they differ from ashwagandha in mechanism and effect.

• Melatonin is a hormone naturally produced by the pineal gland that signals the body to prepare for sleep. Supplemental melatonin is particularly useful for sleep disorders involving circadian rhythm disruption, such as jet lag or shift work sleep disorder. However, melatonin isn’t recommended for long-term use in the UK without medical supervision, especially for children.

• Magnesium plays a role in over 300 biochemical processes, including nervous system regulation. Magnesium supplements can help ease muscle tension and reduce anxiety, both of which support better sleep.

• Ashwagandha, by contrast, works primarily on stress pathways and the HPA axis, making it more suited to people whose sleep problems stem from stress, anxiety, or adrenal dysregulation.

Many people combine magnesium with ashwagandha for complementary benefits. However, combining melatonin with ashwagandha may not offer much additional benefit unless circadian issues are at play.

Is It Legal and Safe in the UK?

Ashwagandha is legal in the UK and can be sold as a food supplement, provided it meets safety and labelling standards set out by the Food Standards Agency (FSA) and the Medicines and Healthcare products Regulatory Agency (MHRA).

As of 2025, ashwagandha is not classified as a medicinal product in the UK unless marketed with therapeutic claims. Products must not suggest treatment of disease unless licensed as a medicine. Consumers should look for reputable brands that comply with FSA regulations and avoid any that make unsubstantiated medical claims.

There are currently no widespread safety alerts or restrictions against ashwagandha by UK regulators, though the FSA has reminded companies that all novel foods must be authorised. Some ashwagandha extracts may fall under novel food regulations, especially those using concentrated forms not commonly consumed before May 1997 in the EU.

Who Should Avoid It?

While ashwagandha is generally well tolerated, it’s not suitable for everyone. People in the following categories should speak to a GP or pharmacist before using ashwagandha:

• Pregnant or breastfeeding individuals

• People with autoimmune conditions (e.g., lupus, rheumatoid arthritis, Hashimoto’s thyroiditis)

• Those on thyroid medications, as ashwagandha may influence thyroid hormone levels

• Individuals taking sedatives, anxiolytics, or antidepressants

• Those scheduled for surgery (ashwagandha may affect anaesthesia)

Ashwagandha may stimulate the immune system or interact with certain medications, which could exacerbate existing health conditions.

Best Time and Way to Take Ashwagandha

For sleep-related benefits, ashwagandha is typically taken in the evening. However, because it works on stress regulation throughout the day, some people take it in the morning or split the dose (e.g., 300 mg in the morning and 300 mg at night).

The most effective doses for sleep in studies range between 240 mg and 600 mg of root extract per day. It’s crucial to check whether a product contains KSM-66 or Sensoril, two highly studied branded forms of ashwagandha, known for their bioavailability and consistent extract strength.

Ashwagandha can be taken:

• In capsule form (most common)

• As a powder (mixed into warm milk or smoothies)

• As a gummy (for taste and ease of use)

Absorption may improve when taken with food, but always follow the manufacturer’s instructions or medical advice.

Side Effects and Interactions

Most people tolerate ashwagandha well, especially at standard doses (300–600 mg/day). However, some individuals may experience:

• Gastrointestinal upset (nausea, diarrhoea)

• Drowsiness or vivid dreams

• Headaches

• Dizziness

• Thyroid hormone fluctuations

In high doses or when combined with sedatives or alcohol, ashwagandha may increase drowsiness. It may also interfere with thyroid medications by raising T3 and T4 levels.

Drug interactions have been reported with:

• Benzodiazepines

• Antidepressants

• Immunosuppressants

• Thyroid hormone replacement therapy

• Barbiturates or other sedatives

As always, it’s advisable to consult with a healthcare professional before introducing any new supplement—especially when taking prescription medications or managing chronic conditions.

Best Ashwagandha Sleep Products in the UK

Here are some of the most reputable ashwagandha-based sleep products available to UK consumers:

• Nutravita KSM-66 Ashwagandha Capsules – Contains 600 mg KSM-66 plus black pepper for absorption. Vegan and made in the UK.

• Pukka Night Time Capsules – Combines organic ashwagandha with valerian and other calming herbs. Soil Association certified.

• Himalaya Ashwagandha Caplets – A long-standing brand with full-spectrum root extract, often praised for consistency.

• TRIP CBD & Ashwagandha Gummies – Offers a dual adaptogen + calming cannabinoid approach. Sugar-free and vegan.

• Feel Natural Ashwagandha Powder – 100% organic, suitable for drinks or smoothies, with no fillers or additives.

When choosing a product, opt for brands that are third-party tested, clearly label extract type and concentration, and comply with UK supplement regulations.

Final Thoughts + Related Articles

Ashwagandha is a promising, science-backed adaptogen with growing evidence supporting its role in improving sleep quality—particularly for those affected by stress and anxiety. While it’s not a cure-all, it may provide gentle and sustained support for better rest when used consistently.

Always source supplements from reputable UK-based brands, consult a medical professional if unsure, and avoid combining ashwagandha with other sedatives unless advised.