How does caffeine affect sleep patterns and sleep quality?

Caffeine’s role in sleep disruption is well known, but it’s also highly variable.

Indeed, some people can drink a double espresso after supper and fall straight to sleep half an hour later; yet others have to be incredibly careful about the caffeine consumption, such as drinking coffee in the afternoon or evening or they’ll be awake for hours trying to sleep.

One thing we can all agree on is that caffeine is consistently great at treating the symptom of sleepiness, but it can actually lead to long term fatigue and sleepiness by disrupting sleep patterns.

But, how strong is the effect of caffeine on sleep patterns?

Swiss scientists have done some research on this and suggest that 200 milligrams of caffeine consumed in the morning can still be seen affecting brain wave activity in the evening.

However, this isn’t to say that the effects were strong enough to affect sleep in a significant way, but more that if the person is more sensitive to caffeine, there is a potential for sleep disruption even with caffeine consumed much earlier in the day.

And there’s another important factor – what is your chronotype?

The best way to describe what a chronotype is with a question: are you an owl or a lark?

Your genetics will denote how your body clock is more prone to to be awarke early, symbolised by the lark, or prone to staying up later, symbolised by the owl.

So, if you are a lark or a “morning person”, your body clock is synchronised to have more energy earlier in the day and the caffeine may disrupt your sleeping patterns.

Conversely, owls or “night people” will not feel the effects caffeine consumed earlier in the day.

So, how does caffeine effect sleep quality?

Caffeine can also affect our sleep quality. So far the research points to caffeine having no effect on REM sleep, but decreases Stage 3 and Stage 4 sleep, which constitutes 20% of our daily sleep as well as being some of our most restorative sleep periods. So, it is sensible to be more aware of the possible effects of caffeine on sleep quality.

So, caffeine can significantly reduce the quality of one's sleep. It interferes with the deep sleep stage, which is crucial for restorative rest. This reduction in sleep quality often results in individuals feeling less refreshed upon waking, even if they have slept for an adequate number of hours.

Furthermore, caffeine increases the time it takes to fall asleep, a phenomenon known as increased sleep latency. This delay can result in shorter overall sleep duration, as individuals may not compensate for this delay by waking up later. The cumulative effect of reduced sleep duration over time can contribute to chronic sleep deprivation.

Additionally, caffeine can disrupt normal sleep patterns or circadian rhythms. This disruption can be particularly problematic for individuals who consume caffeine late in the day. The stimulating effects of caffeine can linger for several hours, with its half-life (the time taken for the body to eliminate half of the caffeine) ranging from 3 to 5 hours. Consequently, an afternoon or evening coffee can still impact sleep quality at night.

Overall, while caffeine is widely used for its stimulating effects, its impact on sleep can be detrimental, especially when consumed in large amounts or later in the day. Moderation and awareness of one's own sensitivity to caffeine are key to minimising its negative effects on sleep.

Two ways of managing your caffeine consumption is either blending decaffeinated coffee with regular coffee, such as a 50-50 half caff blend, to reduce your caffeine intake; or consuming more decaffeinated coffee particularly after midday to mitigate the effects of caffeine on sleep quality.

Here at, we recommend the Swiss Water Process of decaffeination, which uses water (no chemicals) to decaffeinate the coffee beans and is 99.9% caffeine free.

To find out more, please visit or check out our youtube channel for more videos on decaf, caffeine and coffee topics.

IMPORTANT: This information is intended to support, not replace, discussion with your doctor or healthcare professionals. Nothing in the content or products should be considered, or used as a substitute for, medical advice, diagnosis or treatment. You should always talk to your health care provider for diagnosis and treatment, including your specific medical needs.

September 19, 2022 — Guy Wilmot

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