How Caffeine Impacts Your Sleep And Body Clock

February 7, 2025

How Caffeine Affects Your Sleep Cycle

Verified By
KIMS-SUNSHINE
Specialist,
07 February, 2025

Coffee has literally been described as motor oil or fuel by most of us. Research has shown that it is widely used by over 90% of the world’s population to stay awake and concentrate better. The highly noticeable after effects of coffee come from caffeine- a molecule that is easily absorbed by the gut due to its very high bioavailability, though there are hundreds of other organic compounds that make it a beneficial drink to consume on a daily basis. Caffeine has been classified as a stimulant which prevents the accumulation of certain sleep inducing messenger molecules in the brain, which means the person is more alert than before. Each person has genes that are responsible for the breakdown of caffeine- and it functions differently in everyone. This is why someone may feel super tired and sleepy even after having lots of coffee in the evening, while someone else may have trouble sleeping at night when they have had half a cup of coffee that same afternoon.

How Caffeine Impacts Your Sleep And Body Clock

The safest amount of caffeine has not yet been determined for everyone to consume, without facing any issues, though the FDA maintains that 400 mg is a good enough value. Some people may feel jittery or anxious when they have so much, while others may be totally fine even with more. Most people associate an espresso with more caffeine, though it may not be necessarily true. An espresso is very less in quantity when compared to a full mug of filter coffee (which even when diluted with milk is much larger in volume as the amount of decoction needed depends on the volume of milk), but if you have same volumes of espresso and filter coffee, then yes- espresso definitely has more caffeine. Coffee is just one of the many possible caffeinated beverages that people consume on a daily basis. Caffeine goes to work in the brain and prevents the adenosine – a molecule that begins to accumulate once someone is awake, from binding to its receptor. Adenosine continues to be formed in the brain through the day, but when you drink something with caffeine, it competes with adenosine for a spot on the receptor and forces you to stay up and feel alert.

Effects Of Caffeine On Sleep Quality And Duration

Studies have shown that caffeine has a huge impact on the body clock. If you have some caffeinated beverage about 6 hours before bedtime, then you sleep an hour less than usual. Most people don’t really associate the caffeine alone with feeling restless and irritated the next day.

Does Caffeine Affect Everyone’s Sleep The Same Way?

The shortest answer is no. The longer answer will give you the reasons for the same. The way caffeine is broken down differs from one person to the other, even if we have the same genes for the pathway. Plus, age also plays a role, as the rate of metabolism is generally better when you are younger, than when you are older. Some people may have coffee, tea or some caffeinated drink everyday or often in a day- which means their body may eventually build a tolerance to it. Small amounts will not really matter for them then.

Conclusion

Since some people may face issues with their sleep schedules, when they have coffee, let us look at some caffeine alternatives for better energy and sleep balance. Good substitutes include chicory tea, herbal tisanes and teas, green tea, matcha, chamomile, lemon tea, peppermint, ginseng. For some people though, cutting down on caffeine can cause withdrawal symptoms, which can make their lives miserable for a few days. But, it is impossible to blame caffeine completely, for your sleep-related failures. You may be working at odd hours, may not get enough sunlight and may have too much coffee to overcompensate – causing you to feel jittery and panicky. The best solution is to stick to a good sleep schedule- where you go to sleep by 10 pm or the same time at night and wake up at 6 am or at the same time every morning. Exposure to blue light can delay melatonin production- which means you won’t sleep well either. So, less caffeine or no caffeine, but no screen time during bed time can definitely help you in the long run!

Frequently Asked Questions

How long does caffeine stay in my system and impact sleep?

Caffeine is broken down within 15-50 minutes of consumption, but can stay for as long as 12 hours in the system- if not metabolised in the normal amounts. So, have coffee by afternoon, so you can sleep at night.

Does caffeine affect deep sleep and REM sleep cycles?

Yes, caffeine can make the REM part of your sleep cycle shorter- which means you won’t feel rested after you wake up the next day.

Are some people more sensitive to caffeine’s effects on sleep than others?

Yes, this is because all of us have genes that break down coffee at different rates.

Does caffeine from tea or chocolate affect sleep the same way as coffee?

Tea generally has less caffeine in it, when compared to coffee but it depends on how long the tea has been processed for, steeped for. The same goes for coffee- the beans and the roast, the amount, etc. The general rule is since both are caffeinated, moderation is your bestie here. Hence, you can’t go around saying tea is good for you and coffee is bad- as it is not so clear.

What are good alternatives to caffeine for energy without disturbing sleep?

You can have herbal tisanes, drink plenty of water, sleep and wake up on time, spend some time outside in the sun daily, exercise and work normally- all of which will essentially tire you out- causing you to fall asleep soon at night.