Coffee Before Exams? (Everything You Need To Know About Studying With Caffeine)

Nobody loves coffee as much as me. Give me a strong cup of the hot black stuff and I suddenly feel I’m capable of anything. That brutal 150-question pharma test? Yep, bring it on.

But is coffee the study hack I think it is? Or am I just kidding myself at the behest of my health? (and, yes, sometimes my wallet – thanks, Starbucks).

This article takes a look at that.

We’ll cover:

  • If drinking coffee before an exam works
  • If it helps us get better grades
  • The why, how and when of caffeine
  • My own personal experiences as a coffee junkie (and medical student)

Here’s everything I think students need to know.

Is Drinking Coffee Before Exams A Good Idea?

Drinking coffee before taking an exam could be a good move. It can help us stay alert and focused. While studies have shown it aids memory retention and recall too.

But, as with most things, there are also things to watch out for.

Those of us not used to drinking coffee won’t see much benefit from a single cup before a difficult test. 

Instead, it’s generally a better idea for regular drinkers. Or students who’ve been drinking it specifically in the study sessions leading up to an exam.

Why? Because of a general theory that mimicking your mental condition (and physical surroundings), leads to less anxiety and a greater sense of ease. Two things which can help massively when it comes to scoring high!

See, I told you there’s a reason I recommend coffee makers as a med school apartment essential…

Related: 7 Med School Apartment Essentials : Supercharge Your Study Space

Can Coffee Help You Get Better Grades?

There’s no conclusive proof that coffee can help you get better grades. There is, however, very good research that, when used as a study aid, it can help in the retention of key information and facts. Something that’s especially important to doing well in exams.

This 2014 study completed by Michael Yassa, professor of neuroscience and psychology at John Hopkins University, shows as much [1]. The study, which looked at two groups of students (one given caffeine, the other nothing), showed that the caffeine group performed better recalling information they’d seen the day before.

“Once they got the caffeine they came back 24 hours later and we tested them. We found that those who were administered caffeine actually had better retention of the information that we taught them the day before. The caffeine enhanced their ability to say this item was similar but not identical to the one they’ve seen before. Memory consolidation is the process of taking memories and strengthening them and making them more permanent. We found that those who were administered caffeine had better retention of the information that we taught them the day before.

This study is good evidence that drinking coffee in your study sessions leading up to exams could be a clever move.

But it doesn’t say you’ll definitely ace or improve your scoring…

Does Drinking Coffee Give You A Study Advantage?

Nutrition Journal’s 2007 study of just under 500 college students (51% coffee drinkers) shows some evidence that coffee helped in preparing for exams. The results lead to several psychopharmacologists reporting that “caffeine gave an advantage” [2] to the one group of students over the other.

More good news for regular drinkers!

Why Caffeine Works Before Exams

Caffeine works well before exams by helping to enhance your alertness and retention. But this is only true when you drink amounts that are correct for your metabolism (more on this later). 

According to Scientific American, this is considered “popular wisdom”.

It’s based on the scientific grounding that drinking coffee gives us positive memory effects as well as helping to “wake us up” [3].

A lot of us going without our morning coffee can probably attest to that. Cue groggy complaining.

But besides these assertions, there’s also evidence that coffee improves reaction times too (something that could help speed up and improve our accuracy responding to test questions). 

That’s something highlighted in a 1993 survey of 9003 British adults, tested on verbal memory, visuo-spatial reasoning and choice reaction time [4].

Psychopharmacologists there noted “improved performance with higher levels of coffee consumption.”

When Coffee Is Bad For Studying

caffeine curve
“caffeine curve” by emdot is licensed under CC BY 2.0

Inevitably, the story isn’t always so rosey when it comes to coffee and smashing exams. 

Sometimes, especially for those not used to it, coffee can make you lightheaded, anxious and even give you headaches. 

That’s why I definitely wouldn’t recommend drinking it before an exam if you’re not used to it. 

A couple of other reasons (and circumstances) it might be bad:

  • Too much of it can give you heart palpitations (according to this Daily Mail article from 2014 [5])
  • Your intellectual performance could take a hit if you overload (so says Brian Morton, chief of the Australian Medical Association Council of General Practice [5])
  • It can adversely affect your sleep (something that will most definitely hinder your performance)
  • It can make you want to rush to the toilet (not ideal in the middle of an exam)

So, the important thing to remember here is this…

Coffee isn’t the perfect study or exam solution for every student. Although it can help, it can just as much hinder you too. Especially if you drink it close to bed or drink too much of it.

Curiously, The University of Leicester (UK) recommends to forego it entirely. You can see that on their exam preparation tips here.

How Much Coffee Should Students Drink?

Students should drink the same amounts of coffee as anyone else. That’s ideally no more than 400 mg of caffeine per day. Which is just under three Starbucks cappuccinos (150 mg each) or four cups of brewed black tea (around 50 mg each).

Now that might seem more than you were expecting. Please note that is a maximum recommendation (according to Mayo Clinic [6]). And it’s intended as a guideline for adults not children.

Interestingly, that’s also the caffeine equivalent of 10 cans of Coke. 

But think of the sugar people. Diabetes isn’t fun.

What Is The Best Coffee To Have Before Exams Or Studying?

The quick answer here is whatever type coffee you’ve been drinking normally. Or your favorite type (if you’ve been mixing up frappes, lattes, capuccinos or whatever else). The important thing is to have something you’re already used to.

The reason there’s so much flexibility is because the power is in the caffeine and not the coffee. You can get a gauge on what’s most powerful using the mg measurements discussed above.

But here’s a useful infograph breaking it all down…

coffee graphic

Go over the normal amounts of caffeine you usually have and you’ll risk facing all the negative benefits (the jitters, the need to pee (or worse), the insomnia etc). 

So my best piece of advice is to keep an eye on your daily consumption amounts and keep that in mind the day of the exam.

And no, I don’t mean fuel up to the max level you’d be at 4pm if your exam was at 8am!

When Is The Best Time To Drink Coffee Before An Exam?

Felix coffee
“Felix coffee” by RaeAllen is licensed under CC BY 2.0

There are a few theories on this but luckily the U.S. Army cracked the case and developed an algorithm [7]. 

According to them, the best time to drink (if you’re drowsy) is right after you wake up and then four hours later. For an exam at 12pm (for example), you’d drink 200 mg at 7:30 am and then another 200 mg at 11:30 (half hour before start time).

The quantities don’t have to be exact. Just what you’re used to.

Given that tests start at different times though, your own calculations will of course be different.

The main point is that caffeine takes time to see effects. While it also depends on your metabolism (regular drinkers will have greater tolerance) too.

To summarize, drink the quantities you normally would at least 0.5 to 3 hours before the start of an exam. 

That should be enough to give you that buzz you need.

Personal Tip: you could trial running this with mock exams, experimenting with drinking times and measuring your performance. Think of yourself like a mad coffee scientist…

How Long Does Coffee’s Effects Last?

Between 3-5 hours is what the current science says. That’s based on the the average metabolism and coffee’s half-life (time it takes for its concentration in the body to halve).

Importantly, this is why most (boring) people will tell you not to drink coffee close in the late afternoon or evening. 

Which is, I hate to say it, sensible advice given caffeine’s effects can last as long as 6 hours (with it still being in your system – but in unnoticeable amounts – for even longer).

General Tips On Drinking Coffee Before Exams Or While Studying

Ok, to round that all up then, what are some general tips to keep in mind when drinking coffee before exams or while studying?

Here are a few:

  • Stay within the recommended limits
  • Time your consumption to the time you most want to perform
  • Drink the coffee you’d normally drink
  • Don’t expect it to be a miracle (taking you suddenly from an D to an A etc)

Drinking Coffee Before An Exam: Reddit’s Tips

And just like those pointers above, I thought I’d also turn to the student communities of Reddit for their advice when it comes to mixing coffee with studies (and exams).

Here’s some of the best comments I found (note: they don’t always fall in line with the science)…

If your exams are enough on their own to make you nervous and jittery, then anything containing caffeine is only going to exacerbate that…That said, if you were like me when I was an undergrad and drank 6-10 cups of coffee a day, anyway, then if the professor allows you to have a beverage during exams and you’re not going to need a “bio-break” halfway through, then what’s the harm? 


This raises some good points (as well as rehashing some of the earlier warnings)…

Study, do all the problems at the end of the chapter (yes, really), go to office hours, take benadryl the night before to make sure I sleep, and then coffee and plenty of water the morning of, and maybe a nice coffee during the exam.


I don’t think Benadryl is a great idea here. But I do agree with the problems at the end of the chapter. That fits perfectly with my philosophy of how to study medicine more effectively!

Around 45 minutes. However I would definitely not start drinking coffee during finals if you’re not a normal coffee drinker (I’m only guessing this might be the case because most people who drink coffee often know how it affects them, ignore this if I’m wrong). In general, don’t start any new habits before an exam.


This one answers when to drink as well as confirming a couple of my own personal ideas on how best to approach drinking coffee before exams.

You get a little less caffeine from capsules though (90% as opposed to 99% when you drink it), and the time it takes for your body to absorb it is 2-3 times slower. so the “kick” of the caffeine in pills is actually less than when you drink it because the absorption is so much slower.


While this one talks about caffeine capsules rather than coffee. But why would they deprive yourself of that delicious coffee warmth?

My Experiences Using Coffee To Study

MEDICAL STUDENT: Living on massive amounts of caffeine, sugar and ramen noodles and forgoing sleep to become a better health professional...
“MEDICAL STUDENT: Living on massive amounts of caffeine, sugar and ramen noodles and forgoing sleep to become a better health professional…” by sylvar is licensed under CC BY 2.0

If you’ve learned anything at all from this article then you’ll at least know I’m a coffee drinker. 

Not a connoisseur by any means but definitely a big fan!

I’ve been drinking coffee through each year of medical school (now Year 4) and have always associated it with productivity and performing well

I have this little baby to thank for that. I can brew 6 cups on this without having to refill. Meaning I can rip through my flashcards and question banks in no time at all.

And still have time left over to write this blog…

Best purchase I ever made in med school (next to my laptop obviously)!

Plus, due, in large part, to this bad boy, I still haven’t failed an exam yet.

Hope I don’t curse myself there…

Coffee Naps

One thing I’d definitely like to explore more though – especially since researching it in my article; 10 Powerful Study Techniques Like The Pomodoro Method, is coffee naps.

Here’s a quick video outlining how it works…

Related Questions

Is Black Coffee Good For Students?

Black coffee is just as good as any other coffee when it comes to study performance. Coffee’s benefits come from caffeine not type. Black could be healthier though, especially as it’s without milk (fat) and usually sugar.

A sugar crash in an exam is much more of a hazard to doing well.

My Exam is 100 Hours Long, Will Coffee Help Me?

One thing that should be said is that coffee may only help with exam performance if your exam durations are kept within reasonable times. In this case I mean short enough times to match the half-life of caffeine (3-5 hours).

For longer exams, try and time your break for a second caffeine round.

And if you don’t get a break then I feel sorry for you. Whatever you’re studying for must suck.

Related: 5 Worst Things About Med School

What Is The Best Drink For Studying?

Water is generally recommended as the best drink for studying. It’ll keep you dehydrated, thus aiding your concentration, and it won’t cause any energy crashes like caffeine or sugar-based drinks can.

Plus it’s bland enough not to distract you.

Are Energy Drinks Good Before Exams?

Energy drinks work on the same principle as coffee. Unlike coffee though they usually have a higher caffeine content and are heavy on the sugar. These things could adversely impact your energy levels (and, as a result, your exam performance).

Red Bull Before Exams: Good Idea Or Not?

Red Bull before an exam, as it has 80 mg of caffeine, could have similar benefits to coffee. This 2017 study [8], conducted among 24 volunteers, suggested positive cognitive effects…

Red Bull was found to produce significant improvements over both the Sugarfree version and the placebo drink on two composite scores from the six working and episodic memory tests; one combining the 12 accuracy measures from the six tasks and the other the average speed of correct responses from the working memory and episodic recognition memory tasks

But like coffee, you have to be careful.

The same risks of consuming too much caffeine apply.

What Should I Do Before Exams To Help Maximize Success?

If you’ve read this far you’re probably the diligent type who searches for every morsel of information that might possibly help give you an edge academically. Gotta respect that.

Coffee aside, the best advice on how to do well in exams is, shockingly enough, to study and consistently put in the work.

That means using evidence-based study methods that are active (not passive).

Luckily I’ve got a few tips there that can help…

Related: Active Recall Strategies (7 Powerful Examples)

Final Thoughts: Coffee Before Exams?

To wrap things up, should you drink coffee before exams? Yes. But only if it’s something you normally do.

Otherwise stick to the water, the exercise, the healthy food and the regular sleep. All the things you should be doing anyway.

But I at least hope you’ve learned everything I feel students need to know about caffeine and coffee!


Image Credit: @anniespratt at Unsplash