Last updated on

My experience with caffeine withdrawal: the science behind the headaches

Article at a Glance
  • Variants in the CYP1A2 gene affect how quickly the body metabolizes caffeine.
  • High doses of caffeine have been shown to inhibit social behavior in mouse models.
  • Caffeine use narrows arteries in the brain. When we stop drinking caffeine, these arteries “open back up,” which causes headaches and other side effects, such as lack of energy, in many people.

Caffeine gives me the jitters, which makes sense in light of my genetics. I am homozygous for the CYP1A2 gene, which means I metabolize caffeine more slowly than some of my buddies who drink espresso rather than warm milk before heading off to bed.

When I was first reviewing my genetic charts, this information made perfect sense to me as I’ve always felt caffeine affected me to a greater extent than many of my friends. If I were to drink a latte before bed, I’d be up half the night tossing and turning, so I usually don’t drink caffeine. And so it was with less than what you would call “health wisdom” that I embarked on a 10 day run of morning lattes and afternoon green tea.

Now, to be fair, this wasn’t exactly a binge worthy of Hunter S. Thompson. I get that drinking coffee in the mornings for 10 straight days isn’t a huge deal, or even a deal at all. However, after giving the morning coffee ritual a try, I also see caffeine in its true role as a drug. And an addictive one at that. I also understand why it’s the world’s drug of choice. But I have no doubt that caffeine is addictive and that it changes behavior patterns, even social behavior.

High dose caffeine inhibits social behavior

Candidly, I think caffeine is part of the reason a coffee drinking friend of mine has delayed talking to a girl at the gym who he knows likes him. Let’s call him Jim. In our conversations about caffeine, he has openly acknowledged that drinking caffeine all day makes him tense. And it’s that tension that can make us just a step slower when it comes to social risk.

Yes, caffeine fosters creativity, but it also breeds anxiety. Turns out these hunches of mine are backed up by science. Mouse models show that high doses of caffeine cause “avoidance-irritability behavior,” which reduces time spent socializing. (R)

With all that said, let me get into the details of my little latte run.

As I’ve already alluded to, this doesn’t end well.

Progression of caffeine addiction

During this caffeine period, I was hanging out in sleepy San Diego, which if you haven’t been, is a city characterized by the country’s best weather, and a corresponding dearth of work vibes. Caffeine seemed in some strange way necessary to prevent joining with the collective slumber. I was on Austin time, so I’d wake up at 5:30 every morning and walk my dog, Ned. On these walks, we’d stroll past an open air coffee concept called Lofty Coffee, in San Diego’s Little Italy neighborhood. Here’s this completely outdoor coffee shop, with great branding and a fine selection of different caffeinated drinks to warm you as the marine layer rolled out. The people “inside” looked so happy and content sipping on their various black water beverages. I couldn’t resist. It was time for me to join the ranks of the coffee tribe.

For about 10 days in a row, I ordered a Turkish Latte, which is offered at Lofty with house made coconut milk, and cardmom. On day one, I had a rush of euphoria that lasted an entire day. I felt like I could take on the world. My brain went into high gear. Mood was improved, productivity was up, smiles were in plentiful supply. Optimism flowed. And that ride lasted through about day four. But on day five, I noticed that the buzz wasn’t quite as good as it had been on previous days. When I finished my latte, I immediately wanted another, but to keep things in check, I would order a decaf Americano as a follow up. Later in the day I would have multiple cups of green tea.

In other words, the returns diminished as I drank more caffeine. I was developing a tolerance.

By day 6 or 7, a latte on an empty stomach gave me a little bit of what could best be described as sour stomach. By day 9, I seriously considered ordering a double, but never did. You get the point.

Caffeine withdrawal and breaking addiction

A couple mornings during my run I’d wake up, and think, “you know what, I will skip the coffee this morning, I don’t need it.” But inevitably, I’d show up at the coffee shop for my latte nonetheless, rationalizing the trip the whole way. Hey, coffee does lengthen telomeres, right?

Then, one day I stopped cold turkey. No latte, no decaf Americano, no multiple cups of green tea in the afternoon. What happened next came as a surprise.

I developed full on caffeine withdrawal. I felt like an addict drying out at a rehab center.

The day I opted out was a day marked by a terrible headache, stomach upset, and some lightheadedness. I was irritable and cranky. I legitimately felt like I was sick, except I knew I wasn’t. I stayed in bed a good chunk of the day and got very little done.

As I clicked off more caffeine free days on the calendar, I returned to normal, but the experience of having a true withdrawal from a true drug was a first for me and it was eye opening. It got me wondering, did my CYP1A2 genotype have something to do with the severity of my withdrawal?

I’d read that coffee constricts blood vessels in the brain, and that when you quit, the passageways open back up, which causes a headache. But I wanted to real scoop on what causes withdrawal, so I asked, you guessed it, Aaron, the badass scientist on our team. Here’s what he had to say.

The science of caffeine withdrawal

Thanks John. There’s actually a really nice study which looks at just this effect. Published by researchers from the University of Vermont and Johns Hopkins University School of Medicine, which you can read here if you’re interested in understanding everything. While the study was small, only 16 subjects, it was double-blinded (neither the subjects nor the researchers know which treatment a person is on) which is the gold standard.

The regular caffeine users switched between a maintenance dose of 400 mg of caffeine or a placebo without any caffeine, and at regular points received either high dose caffeine or placebo challenges. The idea behind this switching is to see what effects a chronic and acute withdrawal from caffeine would have on people with differing daily intakes.

To give you an idea of the dosing see this table from Amber’s previous post.

Caffeine comparison

Beverage typeCaffeine per cup (8 oz)
Coffee (brewed)95-165 mg
Energy drink27-164 mg
Black tea (brewed)25-48 mg
Cola24-46 mg
Green tea (brewed)25-29 mg
Decaf coffee (brewed)2-5 mg

Throughout the trial EEGs were recorded to demonstrate brain function, and blood flow through two key arteries was assessed as well.

So what did they see?

Well, acute caffeine abstinence lead to increased blood flow through those arteries which the authors suggest ties in with those severe headaches, which correlate with going cold turkey. This acute caffeine abstinence also led to changes in brain function as measured by EEG, associated with increased drowsiness and decreased alertness. Even the answers to questionnaires taken by the subjects show a similar effect, with increased ratings of words like “tired,” “fatigue,” “sluggish,” weary and decreased ratings of “energetic,” “friendly,” “lively” and “vigor.”

All of which fits with John’s description (and my own experiences when I switched back from strong coffee, to tea). And for further bad news the authors of this study, and others, report that daily intake and length of intake will also significantly worsen the effects of going cold turkey (R,R).

Closing thoughts

Well, there you have it, as it turns out, caffeine withdrawal is caused by increased blood flow through key arteries in the brain, which causes pain in the form of headaches, and presumably dizziness for some people as well.

The more caffeine you drink, the worse the withdrawal will be.

What have your experiences been quitting caffeine? Was it easy? Would love ti hear from our readers in the comments.

John O'Connor

John O'Connor is the founder of Gene Food. He is passionate about nutrition, genetics, and wellness and uses this blog to publish self experiments as well as some of the research that the Gene Food team does internally to highlight stories of bio-individuality.

The very latest on genetics, nutrition and supplements delivered to your inbox!


Leave Comment

  1. Sarah Murray says:

    Thank you Thank you thank you for typing this particular piece of writing. You have no idea how HARD it is to find TRUTHFUL, well rounded articles about the truth of what caffeine can do to people with this particular gene. And in my personal experience, what caffeine can do to people in general without them having a clue of all the insidious ways caffeine has it’s clutches on society.

  2. Toni says:

    Wow thanks for your article! My girlfriend gave me an organic coffee 3 days ago. I have been happily drinking it thinking I’m getting my normal coffee high and then mysterious headache develops with a whacking headache on waking and was feeling very depressed as well, nauseas and light headed when I glance at the label on the coffee jar 99.7% caffeine free! So unknowingly weaned myself off coffee but boy a shock to realise my body was demanding the high from caffeine even though I was actually not intentionally weaning myself, I was just trialing the organic taste! ; ) still have a slight headache but I guess I’ll keep abstaining after the wake-up call!

  3. HyT says:

    Hi John,

    Very interesting article! I am Day 2 cold turkey. Main reason being because I started to notice staining in my teeth. I only really started drinking tea 4.5 years ago after the birth of my first, continued through my second. What I’m shocked about us that I wouldn’t consider myself caffeine addicted. I have maybe 3-4 cups of tea throughout the day, soft drinks occasionally.

    I normally have a cup of tea first thing in the morning, so around 730am. I decided to start my abstinence from caffeine yesterday – so last cup of tea around 8pm the day before last. I would say around 18hrs in I started to get a little headache, a little tired and a little grumpy. 24hrs in those symptoms worsened and added nausea. Exhaustion kicked in here and I ended up falling asleep on the sofa at 7pm after the children. 1120pm woken up by the husband to go to actual bed to sleep.

    I lay there for maybe 10 minutes before having to get up and was violently ill a few times. Back to bed and slept all the way until morning. Morning was the worst of it I think. Very bad nausea, headache, light sensitive, vomiting on an empty stomach. I was curled up in a ball in the dark for the next 4 hours before the symptoms started to abate.

    40hrs after my last cup of tea I am feeling much better. The nausea is mostly gone, no light sensitivity, headache is slightly there but only really noticeable when bending to pick things up. I’m guessing this is to do with putting more pressure on those narrowed vessels but I may be wrong in that. I haven’t really tracked anxiety but I wouldn’t be surprised if that was also affected!

    Keep up the good work!

  4. Jeff says:

    Day 2 cold turkey. I have drank around 48 ounces of coffee a day for decades. I am wondering if going cold turkey is a good idea now… These headaches are awful. I never think of coffee as a drug, just something I enjoy. But wow. This is an eye opener. I want to quit drinking coffee because of anxiety and to see if my blood pressure may come down a bit. Thanks for the article.

    • I would suggest for anyone who is thinking of quitting caffeine cold turkey to do a slow process instead. Sometimes our bodies go through more stress quitting something cold turkey then weaning down. Here’s a example that will make your intolerable life without caffeine much more tolerable. The first day without caffeine you wake up and your normal, because your body doesn’t know you’re about to take its livelihood away from it so skip the morning brew and start your daily routine. You were slowly in the middle of the days start to feel the drowsiness and headache creep up on you, that’s when you ran the organic green tea bag that’s going to save your life through this journey. Put that one tea bag in steaming hot water and feel your headache go down slowly. Then go to bed early that night. The next day wake up and you’re gonna feel crappy you’re not gonna be able to think clearly and you’re going to be very sleepy and you might even have a headache go ahead and reach for the one green teabag again. Steep it for three minutes and make sure to drink tons of water throughout this process because when your body is withdrawing from anything it needs water to flush out the toxins. Now later on in the day you just might come across one of the worst headaches you’ve had yet go ahead step one more green tea bag but try to only drink half of this. This will get you through the night without a banging headache and under the next day. Now you’re on a day three where you can go down to one green tea bag. Try to drink it around noon so it will last you. You can repeate this for day four as well but by day five you should be over the horrible with draws an able to make it on your own without any caffeine at all. I know this is a process but from my experience of quitting caffeine a couple times throughout my life because of anxiety this processed saved me. What some people don’t know is with drawls can cause your horrible anxiety is well So I would go into panick attacks trying to quit until I found this great way to ease my body down from the bumpy caffeine ride it was on.

  5. Jason Shields says:

    Hey John! Fantastic article and well-researched! I’m on day 8 of being caffeine free, although I should mention that yesterday I had an espresso coffee just to test my anxiety levels, mood, etc. Sure enough, I had the worst anxiety that last for at least 5 hours straight!

    I’m a psychologist and I was also born with cerebral palsy. Growing up, I have suffered from depression and horrible anxiety attacks. The medication I was put on made me extremely tired and so I would go to coffee and caffeine for a pick-me-up. I also have an addictive nature so I would go overboard to experience a greater clarity and focus of mind. Since I’ve stopped, the first three days were hell but when I got to day 6, everything leveled out. Our brains are highly adaptable and once you get off of the toxin, you do feel better and more outgoing! Thanks again for your article and testimony!

Leave a Reply

Facebook icon Twitter icon Instagram icon Pinterest icon Google+ icon YouTube icon LinkedIn icon Contact icon Info icon