Is Caffeine Secretly Disrupting Your Sleep?

If you’ve ever found yourself lying awake at night, struggling to switch off, caffeine might be playing a bigger role than you think. Many of us rely on a morning coffee to kickstart the day or enjoy a cup of tea in the afternoon, but did you know caffeine can stay in your system for hours, affecting your sleep even if you don’t feel its effects?

At Devon Duvets, we’re passionate about helping people improve their sleep naturally. We often talk about the benefits of natural, breathable bedding, but what you drink throughout the day can also make a huge difference to your sleep quality.

In this blog, we’ll uncover how caffeine disrupts sleep, how long it stays in your body, the best time to stop drinking caffeine, and some natural alternatives to help you sleep better. Plus, we answer some of the most commonly searched questions about caffeine and sleep, ensuring you get the full picture.

How does caffeine affect your sleep?

Caffeine is a stimulant, meaning it keeps you awake by blocking adenosine—a natural brain chemical responsible for making you feel sleepy. Normally, adenosine levels build up throughout the day, creating sleep pressure that helps you feel tired at bedtime. But caffeine blocks this process, tricking your brain into thinking it’s still alert.

The science behind caffeine and sleep

Several studies have confirmed caffeine’s impact on sleep:

• A study in the Journal of Clinical Sleep Medicine found that consuming caffeine six hours before bedtime can reduce total sleep time by over one hour—even if you don’t feel jittery.
• A study in Neuropsychopharmacology revealed that caffeine reduces deep sleep, which is essential for physical recovery, brain function, and memory consolidation.

This means that even if you manage to fall asleep, your sleep quality may be worse, leaving you feeling groggy the next day.

How long does caffeine stay in your system?

One of the biggest misconceptions about caffeine is that its effects wear off quickly. In reality, caffeine has a half-life of 5 to 6 hours, meaning if you drink a cup of coffee at 3pm half of that caffeine is still in your system at 9pm.

What factors affect caffeine metabolism?

Genetics: Some people break down caffeine more slowly than others.

Age: Older adults tend to metabolise caffeine more slowly.

Liver function: A healthy liver processes caffeine more efficiently.

Medication use: Certain medications, such as birth control pills, can slow down caffeine metabolism.

For some individuals, caffeine can stay in the bloodstream for up to 10 hours, making it harder to fall asleep and reducing overall sleep quality.

When should you stop drinking caffeine?

To optimise your sleep, it’s essential to time your caffeine intake properly.

• If you’re highly sensitive to caffeine, stop at least 10 hours before bed (so if you sleep at 10pm, no caffeine after 12 noon).
• If you metabolise caffeine at an average rate, avoid caffeine 6 hours before bed (so no coffee after 4pm).
• If you don’t struggle with sleep but want to optimise it, try cutting off caffeine intake after mid-afternoon (around 2pm or 3pm).

For those who enjoy a warm drink in the evening, try caffeine-free herbal teas such as chamomile, rooibos, or peppermint

What are the hidden sources of caffeine? 

It’s not just coffee that contains caffeine - many other drinks and foods do, too.

• Black and Green Tea – 20-70 mg per cup
• Matcha and Yerba Mate – 60-80 mg per cup
• Dark Chocolate – 10-50 mg per serving
• Soft Drinks (Coca Cola, Pepsi, etc.) – 30-50 mg per can
• Energy Drinks – 80-300 mg per can
• Decaf Coffee – Still contains small amounts of caffeine

If you struggle with sleep, check labels carefully and limit caffeine intake later in the day

Can caffeine cause sleep disorders like insomnia?

Yes, excessive caffeine consumption can contribute to insomnia by:

• Delaying sleep onset – making it harder to fall asleep.
• Reducing deep sleep – leading to more frequent awakenings.
• Causing next-day grogginess – resulting in a vicious cycle of caffeine dependence.

If you regularly experience sleep disturbances, consider reducing caffeine intake or stopping it completely for a few weeks to see if your sleep improves.

What caffeine-free alternatives can help with sleep?

If you’re looking to cut back on caffeine without giving up your warm evening drink, try:

• Chamomile tea – contains apigenin, a natural compound that promotes relaxation.
• Rooibos tea – naturally caffeine-free and rich in antioxidants, and can come with some delicious flavourings, such as vanilla.
• Peppermint tea – helps with digestion and relaxation.
• Warm milk with honey – a traditional sleep aid due to its tryptophan content.
• Golden milk (turmeric latte) – anti-inflammatory and calming before bed.

Replacing afternoon and evening caffeine with these alternatives can significantly improve your sleep quality over time.

A few tips to help improve your sleep naturally

If you’ve been struggling with falling asleep or waking up tired, caffeine could be the hidden culprit. Making small changes to your daily habits can make a big difference to your sleep quality, and these include:

• Cutting off caffeine in the afternoon
• Replacing evening drinks with herbal teas
• Creating a relaxing bedtime routine
• Using breathable, natural bedding

At Devon Duvets, our individually handcrafted,100% British wool duvets are made by our seamstresses in our Devon-based workshops. Natural, sustainable and chemical-free, they help regulate body temperature and create the perfect sleep environment, so you can wake up feeling refreshed. To create a relaxing space in your bedroom, check out our gorgeous Cherish Nature range and read our blog about the best bedrooom colours for sleep.