Is It Bad To Drink Coffee At Night?

If you’re like me, you drink a fair few cups of coffee throughout the day, and sometimes drink coffee late in the afternoon without thinking about if it will affect sleep that night.

To be honest, I usually don’t have trouble getting to sleep, but I would definitely describe myself as a night owl.

(Being comfortable with being fully alert and awake way past midnight and quite often, working late into the night.)

Sound familiar?

I wanted to know is this ‘night owl’ way of life linked to coffee and caffeine? Is it bad to drink coffee at night and will it affect sleeping patterns?



Coffee in the evening


We know that the consumption of caffeine gives us a kick and a pick me up boost, caffeine does affect sleep, but not instantly.
For example, you could drink a cup of coffee and fall straight asleep – the effects aren’t instant.

The body processes the coffee which takes a little while and then you get the effects of the caffeine.

(Which is why if you drink a cup of coffee before taking a nap, you will wake up feeling more refreshed.



What does science say – is coffee making us night owls?

It has been proven that the caffeine in coffee does affect the natural body clock of people. 

At night time, the body releases ‘melatonin’ which is a hormone that is controlled by the body natural internal clock. (Also known as ‘Circadian Rhythm’).

By drinking caffeine, the body natural clock is altered and the production of melatonin (the hormone released at night) is delayed somewhat – meaning that the body’s natural ‘night time’ is pushed later.

This is why you may feel awake and fully aware late at night without even realising it was anything to do with the coffee you drank earlier!

This may sound strange to you (you may be thinking; how can a cup of coffee in the afternoon adjust my internal body clock?!)

This very interesting study, conducted by Kenneth P. Wright Jr., a co-author of the study and director of the Sleep and Chronobiology Laboratory at the University of Colorado explores how caffeine affects the internal body clock.

In his study, five healthy people spent the night in a laboratory, their melatonin levels were monitored. They were all given a pill, three hours before bedtime, some contained no caffeine and other contained the same amount of caffeine as two shots of espresso or a large coffee.

The people that had taken the caffeine pills had a delayed release of melatonin (by about 40 minutes) the researchers found. 

This test was also repeated on different occasions and different participants were given the caffeine pill and again some were given a placebo pill. The results were the same, those participants who had consumed the caffeine has a slower release of melatonin than those who had no caffeine.

This study is further documented on Live Science.



Is it bad to drink coffee at night?



So what does a ‘delayed release of Melatonin’ mean for sleep – is this bad?

Your body will naturally readjust after being changed, just like when you recover from jet lag after going to a country with a different time zone.

You may be wide awake at midnight still and think you are a night owl, when really it could just be linked to the afternoon cups of coffee.

There are no results to be found as to whether multiple doses of caffeine accumulate and have more of an effect on the internal body clock. Now that is a study I would like to see.



So is it bad to drink coffee at night?

If you aren’t too worried about disrupting sleep patterns then no, it’s not bad to drink coffee at night.

The side effects of drinking coffee that are of course, the caffeine hit that can wake you up and make it difficult to get to sleep. However, people have different tolerances to caffeine and some people won’t be affected at all and will get to sleep just fine.

The study mentioned above shows that coffee with caffeine can adjust your internal body clock and trick your mind into thinking it is daytime and you may feel awake even hours after consuming the caffeine.


The bottom line is, if you’re worried about it being bad to drink coffee at night, just switch to a decaf coffee instead. The decaf coffee won’t keep you awake.

If you’re worried about coffee being bad to drink at night time because of it dehydrating you, read out post about whether coffee dehydrates you and see the common myths busted!