What are sleep teas and do they actually work?
As a nation, we are obsessed with sleep, and yet surprisingly bad at actually doing it.
The UK often ranks poorly in international surveys for sleep quality, and some data suggests as many as three quarters of us don't get the recommended numbers of hours per night – leading to what is known as 'chronic sleep debt'.
So why are we all so restless? In part, because we have so much fighting for our attention. Between the dopamine hit of late-night scrolling and the blue light that suppresses our melatonin, our internal circadian rhythms are knocked off course. Throw in PM work emails to spike our cortisol levels, and it’s no wonder we’re looking for quick-fix solutions.
This ‘sleep crisis’ has fuelled a booming market for functional beverages, with shelves packed with night time powders and botanical elixirs promising the benefits of magnesium, L-theanine, and adaptogens. But as these drinks transition from niche health stores to supermarket staples, the question remains: do any of them actually work, or are they all simply placebos for a modern life that refuses to slow down?
Whilst some of the ingredients in sleep teas have been suggested to help, there is a distinct lack of good evidence that they do in fact help. The most likely impact they will have is on helping an individual relax before bed, both in terms of the ritual – as well as some of the ingredients, which have been demonstrated to relax people to differing degrees.
What are sleep teas, powders and drinks?
The sleek packaging and pseudo-scientific vocab may be new, but the concept of a bedtime herbal drink is ancient. The Ancient Egyptians used chamomile for its sedative properties, while medieval Europeans imbibed lavender-infused tonics and valerian root to ward off restlessness.
The 21st century version seems to be trying to bridge the gap between traditional herbalism and modern nutritional science. While old favourites like valerian and lavender remain popular, new sleep teas proclaim their additions of magnesium glycinate or L-theanine, or mushroom-based powders.
These drinks now often come as pre-packaged powders or sachets, designed to be stirred into hot milk or water, or even as ready-to-drink shots. And they are popular: nearly 30% of UK households buy some kind of functional drink, and sleep-focused products have seen a 24.5% surge in sales, according to reports cited by The Times, with the market projected to reach £137 million in 2026.
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Common sleep tea ingredients
L-Theanine
What is it? An amino acid primarily found in green and black tea leaves. Unlike caffeine, which jolts the system, L-theanine is said to promote ‘alert relaxation’ without drowsiness.
Claims vs. Reality: Some studies have shown that L-theanine can increase alpha brain waves, which are associated with relaxation and reduced stress and anxiety, thereby improving sleep quality. However, findings are often inconsistent.
Trials using L-Theanine to examine sleep latency (how long it takes to fall asleep) would typically use doses of 200-400mg. A standard cup of black tea contains around 25mg, though some manufacturers are now fortifying their blends to reach higher, clinically relevant doses.
The bottom line: Proponents say that L-Theanine is one of the more scientifically-backed ingredients for quietening a busy brain. However, as the authors of a 2025 study in the journal Nutrition Research concluded, ‘the science does not yet match the hype’
Lavender
What is it? A fragrant purple flower from the Lavandula genus, used since antiquity for its calming scent. Its primary active compounds are linalool and linalyl acetate.
Claims vs. reality: Most research into lavender’s efficacy focuses either on aromatherapy (inhalation) or on taking Silexan (a high-potency, oral standardised oil capsule). While inhaling lavender has been shown to lower heart rate and blood pressure, drinking it as a tea is less studied. The heat of the water may even evaporate some of the volatile oils that provide the calming effect before you take your first sip.
The bottom line: Lavender may help you feel calmer, but there is little high-quality evidence that a lavender-flavoured tea alone will transform your sleep. For therapeutic effects, standardised oil capsules are generally more effective than a tea bag. As with any supplement or medication, you should check with a healthcare professional to determine whether Silexan is appropriate for you.
Valerian Root
What is it? An herb native to Europe and Asia, often referred to as ‘nature’s Valium.’ The root has a distinct aroma likened to dirty socks, stinky cheese, or unwashed feet!
Claims vs. Reality: Valerian is among the better-studied herbal sleep aids. It is thought to work by inhibiting the breakdown of GABA, a chemical messenger that helps the brain ‘shut down.’ However, a large meta-analysis study in 2023 found that although many people reported sleeping better, objective measures (such as time to fall asleep) showed only modest improvements. Most trials use doses between 300mg and 900mg; a single tea bag rarely reaches these concentrations.
The bottom line: Even the strongest study results show only a modest benefit. It is also very important to consult a GP before using valerian as it has potential side effects and interactions with other medications, including sedatives, as well as alcohol.
Chamomile
What is it? A daisy-like herb containing apigenin, an antioxidant that binds to certain receptors in your brain that may promote sleepiness.
Claims vs. Reality: Chamomile is the most popular bedtime tea, yet clinical evidence for any effect on insomnia is surprisingly thin. A 2011 study found that while chamomile didn't significantly help people fall asleep faster, it did improve ‘daytime functioning’ for those who drank it. A more recent meta-analysis found that it significantly improved sleep quality - but again, this was at a clinical dosage unlikely to be found in a cup of tea.
The bottom line: Evidence may be relatively thin, but chamomile is generally considered a ‘safe’ choice, with very few side effects and a strong placebo-by-association effect. It won't cure chronic insomnia, but it’s an excellent tool for winding down.
Ashwagandha
What is it? An ‘adaptogen’ long used in Ayurvedic medicine to help the body manage stress by modulating cortisol levels.
Claims vs. Reality: Recent studies suggest that Ashwagandha can improve sleep quality, but it isn't an instant fix. Clinical doses are usually around 600mg daily; most teas provide a fraction of this, often using the powder for flavour rather than function.
The bottom line: It may show promise for long-term stress management, but a one-off cup of Ashwagandha tea won't help you sleep better tonight.
Tart Cherry
What is it? A juice concentrate (specifically Montmorency cherries) that is naturally rich in melatonin, the hormone that regulates sleep.
Claims vs. Reality: Studies do seem to show that tart cherry juice can increase sleep efficiency and duration. However, the dose is the issue: you typically need 30ml of concentrate (about 100 cherries) twice a day. A tea containing ‘cherry flavour’ or a small amount of dried fruit won't have any effect.
The bottom line: Look for high-strength concentrates rather than flavoured tea blends. But also be aware that while considered safe, tart cherry juice contains sorbitol, a natural sugar alcohol which can cause stomach pain and diarrhoea in some people.
Milk / Oat Milk
What is it? Traditional dairy or fortified grain milks are often used as the base for so-called ‘moon milks’ or bedtime lattes.
Claims vs. Reality: Dairy milk contains tryptophan, an amino acid that produces serotonin and melatonin. However, you’d need to drink far more than you'd realistically drink to get a therapeutic dose. The real benefit is psychological and physiological: warm liquids are soothing, and the carbohydrates in oat milk can help tryptophan cross the blood-brain barrier.
The bottom line: The warmth factor is likely more effective than the tryptophan content. Though watch out for oat milk with added sugar, which could cause a glucose spike that disrupts your sleep later in the night.
CBD (Cannabidiol)
What is it? A non-psychoactive compound derived from the hemp plant, touted for its ability to reduce anxiety.
Claims vs. Reality: CBD may be bioavailable when taken as an oil under the tongue, but much of it is lost during digestion when drunk in a tea. Research suggests high doses (above 150mg) are needed for any effect, yet most retail drinks contain only 5mg to 15mg.
The bottom line: At the low doses found in most teas, CBD is unlikely to do much to help sleep. There has been relatively little research into the safety of taking a lower daily dose over a long period of time, and there are many concerns about the reliability of CBD product labelling.
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So why does a bedtime tea work for me?
If most tea bags or sleep teas don’t contain enough to have any physical effect, why do so many people feel sleepier after a single mug? The answer lies in the intersection of psychology and physiology.
The human brain is remarkably good at association. By brewing a specific tea at the same time every night, you are essentially engaging in ‘sleep conditioning’ - training your brain to associate the specific scent of lavender or the warmth of the mug with the act of switching off. This ritual signals the nervous system to shift down a gear in preparation for sleep.
There is also a physical effect, if not the one claimed by the manufacturers. Drinking any warm liquid causes a slight rise in your body temperature, followed by rapid cooling as your blood vessels dilate. This drop in core temperature is a biological trigger that tells your brain it is time to sleep.
So the temperature of your night time drink is probably doing a lot more work than whatever herbs are in it. And finally, just because something is a placebo, doesn’t mean it doesn’t work: even in clinical trials for insomnia, the placebo group can show substantial improvements. So if you believe your particular favourite night time blend will work, then your brain releases its own calming chemicals - ensuring it does.
When should you drink sleep teas?
As the primary effect of these teas is to start the wind-down before bed, timing may be important. For the best results, aim to finish your cup 60 to 90 minutes before you hit the pillow.
This window allows the warmth of the liquid to begin cooling your core temperature. It also means any active botanical compounds - if they do have any effect - have time to kick in.
Perhaps more crucially, it’s also good timing for your bladder. Drinking fluids too close to lights-out time can lead to nocturia (waking up to pee), which undoes all the hard work your tea just did.
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Are sleep teas safe?
While usually benign, natural does not always mean guaranteed safety. The biggest risk isn’t typically the tea bag itself, but supplement stacking. For example, the NHS recommends a daily limit of 400mg of magnesium from supplements; if you are already taking a multivitamin and a magnesium capsule, adding a fortified sleep powder could put you well over this limit.
You should also be wary of unverified or ‘extra strength’ blends, especially those sold on social media platforms. These can sometimes contain unlisted ingredients or potentially higher than safe concentrations of herbs like Kava, which is banned in the UK and many other countries due to links with liver toxicity.
Be alert also for any blends that contain St John’s Wort, which can interfere with many medications, including the contraceptive pill, antidepressants and blood thinners. You should always check with your GP or medical professional if you are on prescription medication before starting a daily herbal sleep ritual.
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What we’ve learnt on sleep teas and bedtime drinks
The consensus is clear: a sleep tea isn't a silver bullet, but that doesn’t mean they aren’t useful: they can indeed be a powerful psychological anchor. If you optimise your sleep environment with earplugs, a cool room, and a comfortable mattress, and ditch any late-night caffeine and alcohol, the act of brewing a tea signals that your wind-down window has begun. By stepping away from the screen and into the ritual, what you actually drink may be largely irrelevant — what is important is that you are giving your mind the permission and the space it needs to finally drift off.
This article is for general information only and should not replace medical advice from your GP or healthcare professional.