How Late is Too Late for Coffee? (Essential Reading)

My wife and I drink around two to three cups of coffee every day, but usually don’t have one after lunch. So just how late is too late for drinking coffee?

The caffeine in coffee blocks your brain’s adenosine receptors, which are the neurotransmitters that tell your brain when it’s tired. So in general it’s recommended that you stop drinking coffee at least six hours before you want to sleep.

Let’s dive down into the subject of afternoon and evening coffee drinking in more detail, and discover what caffeine does to your body to stop you from sleeping, and what rules you should follow when drinking coffee later in the day…

Is It Ok to Have Coffee at Night?

Well, if you’re on a shift at the ER or work down the 24/7 store, coffee at night is fine!

The real question is, is it alright to have coffee close to your bedtime (whenever that may be)? Generally speaking, no, it’s not OK to have coffee at night, and here’s why.

Coffee, unless it’s decaf, contains caffeine. This naturally occurring chemical blocks your brain’s adenosine receptors, which are the neurotransmitters that tell your brain when it’s tired.

So, if you consume caffeine close to bedtime, your brain won’t have got the message that you need to sleep.

If you want to know more about the effects of caffeine on adenosine receptors, watch this short film.

How Long Will One Cup of Coffee Keep You Awake?

This depends on the caffeine strength of the coffee and your own personal caffeine tolerance; however, it’s recommended that you stop drinking coffee six hours before you want to sleep.

Caffeine peaks about 40 to 50 minutes after you’ve drained your coffee cup, then gradually leaves your system. It may not have completely left your body in six hours, but there won’t be much left.

Does Drinking Coffee in the Evening Affect Your Sleep?

Yes, drinking coffee in the evening can affect your sleep, because caffeine clocks the neurotransmitters that tell your brain it’s bedtime.

However, “evening” is a bit of a general term. Can you stop off for coffee with a colleague after work? If you reach the coffee shop at five and don’t generally go to bed much before midnight, absolutely.

However, if by evening you mean after dinner, this may be getting a bit late for anyone who isn’t a night owl or a super-desensitized caffeine-head. For most of us, the unusually late caffeine means we’re still alert at bedtime, even if we’re physically tired.

Stick with the six-hour rule when you can. Want to go to bed at ten? Make sure you’ve had your last cappuccino by four pm. You get the idea. 

Does Water Flush Out Caffeine?

If you think you’ve had too much coffee or had a too-late latte, you could try flushing it out of your system with a few glasses of water.

The evidence for this is more anecdotal than scientific; however, because dehydration can make you feel even more jittery, drinking water will certainly help any excess-caffeine symptoms. 

A note here: caffeine is a diuretic, which means it makes you need the bathroom more often. Add a few drinks of water to this, and your sleep will definitely be disturbed; however it will be your bladder keeping you awake, rather than your buzzing brain.

Eating fiber-rich food is another way to calm down the caffeine hit. Try beans, lentils, grains, and nuts.

What Time is Too Late for Caffeine?

We know that caffeine inhibits the neurotransmitters that help you get sleepy, keeping you alert.

So, what time should we have our last cup of joe for the day? (For the sake of this article, let’s say that you work “normal” hours, not nights or early/late shifts.).

Let’s consider the relative merits of coffee drinking in each time slot below…

Is 3 O’clock Too Late for Coffee?

We often hear people say things like “I have a no-coffee rule after three”, and that seems to be a common approach to coffee drinking. Working on the six-hour rule, this means that your body will be suitably low-caf for a nine pm bedtime.

Given that few of us go to bed this early, this makes 3 o’clock a pretty early hour to stop drinking caffeinated coffee. We reckon we could push that by at least an hour or so…

Is 4 pm Too Late for Coffee?

4 pm seems a pretty sensible time to stop drinking coffee.

While you won’t be completely free from caffeine, your sleepy neurotransmitters should be working OK again by ten, in time for you to start winding down for the night.

Is 5 pm Too Late for Caffeine?

This is actually quite a nice time to go for a cup of joe, maybe with a colleague on the way home from work, or stopping off at the coffee house to meet your partner before heading home. But will you regret that 5 pm coffee later in the evening?

If you stay up fairly late, until 11 or 12, a coffee at 5 pm is fine. If you prefer to go to bed earlier, a coffee after work may be pushing it.

Is 6 pm Too Late for Coffee?

Now we’re entering the territory of the true night owls… If you have a cup of coffee at 6 pm, you may still be alert at midnight. This is fine if this suits your natural rhythms (and if you don’t have to be up at five…), but it’s getting a bit late for a lot of people.

Work report deadline? Feel like a Netflix binge? No work in the morning? Go ahead and enjoy a brew. Otherwise, this is quite a late hour to be consuming caffeine. 

Is It Ok to Drink Coffee at 7pm?

If you have a cup of coffee at 7 pm, you may find you’re still alert at 1 am or even later.

For the seasoned coffee drinker (and by this, we mean at least four cups a day), caffeine may not have such a big effect, and they might still happily drift off before midnight. 

However, if you’re a more modest coffee drinker, having a cup of coffee at 7 pm will affect your ability to get to sleep. While the caffeine will be gradually leaving your body, there might still be enough left in you to make sleep a struggle.

But coffee is such a lovely drink, and it’s actually a nice way to round off a meal. If you enjoy the flavor and aroma of coffee, invest in a good decaf for the evenings.

You’ll still have the enjoyment of drinking a cup of coffee, but you shouldn’t have any trouble getting to sleep after it.