The first sip works like a switch. The fog lifts, the shoulders drop, the day becomes possible. It feels like energy arriving. Most of it is something else: the end of a small withdrawal that started while you slept.
Caffeine gives energy the way a loan gives money: it arrives now and gets paid back later, with interest, in sleep, nerves and blood pressure. And it's lent out in far more places than the coffee cup.
To quit coffee is to pay it off, and that part hurts for a while. But caffeine withdrawal keeps a predictable timetable, one cup in the middle of it springs a trap that ends a quit on day two, and there are two good ways through. On the other side is a morning you wake up to without needing anything at all.
You are not the first creature to sign up. The plant did not make caffeine for you. At the concentrations found in leaves and seeds, caffeine stops insects feeding and kills them, which makes it, quite possibly, a natural insecticide. In the flowers it does something subtler. Honeybees given nectar laced with a little caffeine were three times as likely to remember the scent of the flower that fed them. In the words of the team that tested them, the plant uses "a drug to enhance memories of reward" to keep its pollinators coming back. The coffee bush has been in the repeat-customer business for a long time.
The loan you've been paying
A poet set caffeine's discovery in motion. In 1819, Goethe watched a young chemist, Friedlieb Runge, demonstrate an experiment, and was so pleased that he handed him a box of prized coffee beans he'd been sent as a gift and told him to use them in his investigations. Soon afterwards, Runge pulled out of the beans the substance that makes coffee work. Once it's inside you, it works like this.
Through the day your brain builds up a substance called adenosine, a slow-rising signal of tiredness. Caffeine fits the same docking points and blocks the signal, so the tiredness is still there, just muffled. It also nudges the body's stress response, the same system that wakes you up when something startles you in the dark, which is where the edge and the racing heart come from.
The brain adapts to being blocked every day. Once it has, the morning cup mostly brings you back to where you'd be without the habit. When the evidence on caffeine, mood and performance was weighed up carefully, the boost regular drinkers feel was best explained as relief from withdrawal, with little or no real gain on top. Measurements of blood flow in the brain and brain waves in daily drinkers told the same story: plenty of withdrawal, and no lasting benefit from the habit itself.
The adapting goes deeper than mood. When 20 regular drinkers spent ten days on caffeine and ten days on dummy pills, without knowing which was which, a part of the brain involved in memory measured smaller after the caffeine days, and the more caffeine in someone's blood, the bigger the difference. What that means for health is not yet known. It does show that the brain you have on caffeine is not the brain you have without it.
Some of the lift is belief. When 88 people were given caffeinated or decaffeinated coffee and told either one, both the real caffeine and the mere belief that they had had it improved their attention and speed, and the belief alone made them feel more vigorous. The ritual is part of the drug. Your barista is partly a stage magician.
Sleep works the same way. If you drink coffee every day and feel you sleep fine, you may well fall asleep easily. When people were randomly assigned to coffee days and caffeine-free days, they slept 35 minutes less on coffee nights. The only way to know how you'd sleep without caffeine is to stop for long enough to find out.
Some borrowers end up on a heroic scale. The French novelist Honoré de Balzac wrote through the night on, reportedly, more than 50 cups of coffee a day. In an essay on stimulants he described his last resort: ground coffee pressed down and taken cold, with almost no water, on an empty stomach. He recommended it to a friend, who thought he'd been poisoned and went back to bed. Balzac died at 51 of heart failure, and whether coffee played a part has never been proven.
Coffee has had its doubters for five centuries. In 1511 a theological court in Mecca banned it for its stimulating effect, until an Ottoman sultan overturned the ban in 1524. Thirteen years is a long time to wait for a cup. Around 1732 to 1735, Bach wrote a comic opera about the habit, the Coffee Cantata, probably first performed in a Leipzig coffee house, in which a young woman declares that without her coffee three times a day she "will turn into a shriveled-up roast goat". It was played for laughs. The roast goat is still with us.
Even the word has a story. "Coffee" came into English in 1582 through the Dutch koffie, from the Ottoman Turkish kahve and the Arabic qahwah. Medieval Arabic dictionaries took qahwah to mean wine, from a verb meaning "to have no appetite". Most likely it meant "the dark one". It still does.
Caffeine hides in more than coffee
Quitting coffee and keeping three cups of strong tea is a sideways step. Black and green tea, matcha, yerba mate, cocoa and chocolate, cola, energy drinks and pre-workout powders all carry caffeine. Count all of it, because the brain does.
The amounts are bigger and less predictable than they look. A pre-workout scoop averages about 254 milligrams, more than two mugs of coffee. A 16-ounce energy drink can hold anywhere from 54 to 328. The same large coffee from the same café, bought six days in a row, swung from 259 to 564 milligrams. An ounce of dark chocolate brings around 23, a headache caplet can carry 65, and an alertness tablet 200. In the US, a label has to name caffeine when it's added, but the amount is optional, and caffeine that arrives inside another ingredient, such as chocolate, goes unlisted. The label is a polite fiction.
Even the figure quoted everywhere, 400 milligrams a day, is a ceiling with small print. The FDA describes it as an amount "not generally associated with negative effects" for most adults, notes how widely people vary, and sets no figure at all for children or pregnancy. Sleep, anxiety and blood pressure all shift well below it.
At the far end sit pure caffeine powders and liquids. One teaspoon of the powder can hold as much caffeine as 28 cups of coffee, less than half a teaspoon taken quickly can bring on seizures, and the FDA links these products to at least two deaths in the US. Some are still on sale.
What withdrawal feels like, and why
Headache is the best-known symptom, and it has a clear cause. Caffeine narrows the blood vessels in the brain. Take it away and they widen, blood flow rises, and the head pounds. Alongside the headache come heavy tiredness, as the adenosine signal finally lands unblocked, a short temper, low mood, trouble concentrating, and sometimes aches and a feeling like the start of flu.
Symptoms follow a timetable. They usually begin 12 to 24 hours after the last caffeine, peak over the next day or two, and fade within about two to nine days. About half of regular drinkers who stop suddenly get the headache. It happens even to people used to the caffeine of a single mug a day, and the bigger the habit, the harder the landing.
The habit forms faster than you would guess. In four blind experiments, withdrawal appeared after as little as three days of 300 milligrams a day, and grew a little worse after one or two weeks. Even 100 milligrams a day, about one mug, was enough to produce it, and whether it came all at once in the morning or spread across the day made no difference. Three days. That is a long weekend away with a coffee machine in the room.
Withdrawal sets a trap. A single cup in the middle of withdrawal clears the headache and the irritability within a couple of hours, and it feels like proof that coffee was helping all along. It's the withdrawal ending. The same relief follows any substance the body has adapted to, and it's why a quit so often ends on the second day.
There is one withdrawal people walk into without choosing it: surgery. Patients fast before an operation, and the caffeine goes with the food. Of 233 day-surgery patients, 82% drank caffeine daily, and afterwards 22% of the daily drinkers had a headache, against 7% of the rest, more with heavier habits. If you have an operation planned, that is a good reason to step down beforehand, or at least to tell the team how much you drink. A headache you could have seen coming is the last thing to wake up to after an anaesthetic.
Caffeine withdrawal is listed as an official diagnosis in the major manuals used to classify disorders, alongside withdrawal from other drugs. Feeling flattened is the drug leaving, and willpower has little to do with it.
The habit itself is waiting in line for the same status. The World Health Organization recognises caffeine dependence as a clinical disorder, and the main psychiatric manual lists "caffeine use disorder" as a condition awaiting more evidence: the pattern of people who cannot cut down even when they know it is harming them. Not bad for a drink served with a biscuit.
Who should quit first
Some people have more reason than others to take this on now.
Anxiety and panic. Caffeine raises anxiety, and sharply above 400 milligrams a day. In people with panic disorder, about half had an attack after the caffeine of several strong coffees, and none after a dummy drink.
High blood pressure. In people with raised blood pressure, one or two coffees pushed it up by about 8 over 6 within the hour, and it stayed up for at least three hours.
A skipping heartbeat. On coffee days, people had about half again as many extra beats from the heart's lower chambers. In one large comparison, people carrying a slow-clearing version of the main caffeine gene had higher heart-attack odds from two cups a day upwards, and more so in younger people.
Bladder and eyes. Above about 450 milligrams a day, urgency incontinence rose by a third, and cutting caffeine eased urgency and night-time trips to the toilet. Caffeine also raises the pressure inside the eye, which matters if you have glaucoma or it runs in your family.
Low iron. Coffee cut the iron absorbed from a meal by 39 percent and tea by 64, even when drunk an hour afterwards. The culprits are plant compounds in coffee and tea themselves, and the iron in red meat, fish and poultry is barely affected, one more reason a meat-based breakfast makes the change easier.
Sleep and heartburn. If you sleep badly or get heartburn after the morning cup, caffeine is part of the picture.
The pill and some medicines. The contraceptive pill made caffeine linger about half as long again, from five and a half hours to close to eight. The antidepressant fluvoxamine stretched it from five hours to 31. If you take a regular medicine, check its leaflet for caffeine, because each cup can stay in your system far longer than it feels.
Giving up cigarettes. Cut the caffeine alongside them. Smoking speeds up how fast the body clears caffeine. When smokers quit and kept their usual coffee, their caffeine levels doubled within three weeks, so the jitters and broken sleep blamed on the missing cigarettes can come from the coffee.
Pregnancy and breastfeeding
Pregnancy is the clearest case for stopping completely. If you're expecting or trying to conceive, keep caffeine out altogether, from coffee, tea, cocoa, cola and energy drinks alike. Caffeine crosses the placenta freely, and the baby's blood ends up with much the same level as yours. Pregnancy also slows the mother's clearance: near the end, caffeine stays in the body about three times as long, so each cup lingers.
The usual advice sets a limit of 200 milligrams a day, and harm keeps turning up below it. Among healthy, non-smoking mothers in the US, the caffeine of about half a cup of coffee a day went with smaller babies, and children whose mothers had more caffeine in early pregnancy were shorter at ages four to eight. Each extra 100 milligrams a day has been linked to a higher risk of miscarriage and of stillbirth. Put all the evidence together and the pattern holds: 14 of 17 combined estimates pointed to harm, no safe level emerged, and the advice that followed was to avoid caffeine entirely.
Caffeine also passes into breast milk, reaching about 80 percent of the mother's blood level within an hour or two. A newborn clears it over days where an adult takes hours, and only reaches an adult's pace at three to four and a half months, so it builds up. That matters most for tired new mothers, who are the people most tempted to lean on coffee.
Children and teenagers
Children are often given caffeine without anyone thinking of it as caffeine: sweet milky tea, cola, iced tea, chocolate drinks. Their bodies are smaller, so the same can is a far bigger hit for their weight. Teenagers who take in more caffeine sleep less and wake more in the night, and sleep recordings of 10- to 16-year-olds found caffeine users had about a fifth less deep-sleep activity early in the night. Dependence comes quickly too. In a small group of teenagers who had caffeine every day, about a quarter met the criteria for dependence, and when children stopped, their attention slowed for about a week.
Energy drinks are the sharp end. Over 13 years, US poison centres logged more than 32,000 calls about caffeinated energy products in under-20s, and seven in ten involved children under six. Keep caffeine out of children's cups from the start, and they never have a habit to break.
Prepare the ground first
Whichever group you're in, the quit itself follows the same path, and it starts before the coffee goes: know what you're taking, and build up the things that give real energy, so the hole you fall into is smaller.
Take stock. Before you start, write down every caffeinated drink, every square of chocolate and every tablet, and put a number on each with the figures above. Starting from an honest total makes every cut count.
Sleep. Go to bed at a regular, reasonably early time, in a cool, dark room. A stretch of good sleep before you start takes the edge off the tiredness to come.
Steady blood sugar. Eat a breakfast that carries you for hours without snacks, built on protein and natural fat. Meat, eggs and fish do this well. A sugary breakfast drops you by mid-morning, exactly when the craving bites.
Daylight. Get outside in the first part of the day, even under cloud, without sunglasses and not through a window. Morning light is the strongest natural signal the body has that the day has started.
Movement and people. A brisk walk, a conversation, time with a dog or a cat: all of these lift alertness and mood without a loan to repay.
Evenings. Dim the lights and put the screens away earlier, so the sleep you're protecting arrives.
Two ways out
There are two good ways to quit, and the right one depends on you.
Stop completely. The fastest route. You get the full withdrawal at once, usually over within about a week, sometimes two for the tiredness. It suits people who do better with clear lines than with rules to manage. The risk is the second-day trap: one cup to make it stop, and you're back at the start.
Step down slowly. Gradual reduction, sometimes called caffeine fading, has long been used to help heavy drinkers cut down with fewer symptoms. It takes longer, from weeks to months, and the withdrawal comes in small, bearable waves. It suits people who've tried stopping dead and gone back, and people with demanding jobs or young children. If you get migraines, it's the safer route: stopping suddenly can set off an attack, and heavy caffeine use can turn occasional migraines into frequent ones.
Neither way is a test of character. Pick the one that fits your life, and if one fails, try the other. If you're pregnant or trying to conceive, the fast route is the one that matches the advice above.
The slow way, step by step
Loosen the link with waking. The first cup is the most automatic one. Start the day with water and daylight, so that waking up stops meaning coffee, and keep whatever caffeine is left to the early part of the day, because caffeine taken six hours before bed still cut sleep by more than an hour. Even the first cup is not clear of the night. Nine men given 200 milligrams of caffeine first thing in the morning still had some of it in their saliva at bedtime, and that night they slept less and less efficiently, with less of the slowest, deepest brain waves.
Measure honestly. Use the same mug, and weigh the coffee or tea leaves for a while. A that reads to a tenth of a gram makes each small cut visible. Cutting down by feel tends to drift back up.
Shrink it or dilute it. Make each cup smaller or weaker, then hold there for several days until it feels normal. Small steps stay under the line. People used to 300 milligrams a day had no clear withdrawal when cut to 200, and it appeared only once the daily amount fell to 100 or less. It is the big drop that bites.
Cut a cup. Once a level feels settled, drop one cup a day and replace it with something you like: a mug of hot water, a herbal tea, or a decaf made with the Swiss Water or carbon dioxide method, which use no chemical solvents. Best Coffee Alternatives, linked below, has why that matters: decaf began in 1903 with a shipment of beans soaked in seawater, and the first process pulled the caffeine out with benzene. is a Swiss Water dark roast, and brews a naturally caffeine-free cup that takes milk well. Decaf still carries a little, 2 to 15 milligrams in an 8-ounce cup, so the final step runs from decaf to none.
Keep going at your own pace. Hold each step until it's comfortable, then take the next. Expect a slip now and then. Treat it as a bad day and pick up where you left off. Stepping down works, but the amount tends to creep back up over the following months, so keep watching it after the last cup goes, and treat a daily cup that returns as the start of a new step-down.
Mind the swaps. Swapping coffee for cola, chocolate or an energy drink keeps the habit alive under another name.
Keep the break. The break was sold to you along with the cup. Firms in Buffalo were giving workers a morning and an afternoon coffee break by 1902, and the phrase took off with a 1952 campaign from the Pan-American Coffee Bureau: "Give yourself a Coffee-Break – and Get What Coffee Gives to You." John B. Watson, the man who made behaviourism famous and later worked with Maxwell House, helped popularise it. The pause away from the desk is worth keeping. Change what is in the mug.
Getting through the hard days
Choose the timing. Start a fast quit, or the last step of a slow one, at the beginning of a quieter stretch: a long weekend, a lighter week at work, well clear of any deadline.
Drink water and keep eating. Regular meals and plenty of water make the headache and the slump easier to carry.
Walk outside. A brisk walk in daylight is the best short-term lift there is without caffeine, and it helps the headache too. 5 Ways to Harness Your Energy and Beat the Afternoon Slump has the head-to-head: tired young women who were short on sleep felt more energetic after ten minutes of easy stair walking than after a caffeine pill.
Check the painkiller. If you take something for the headache, read the box first, because some headache tablets contain caffeine. A caffeinated headache pill is not a way out. It is the same loan in a different envelope.
Give dull jobs another lift. Caffeine boosts the brain's reward signalling, and the size of that boost tracks how alert people feel. That's why the craving bites hardest in front of a boring task: the spreadsheet, the ironing, the pile of paperwork. Pair the dull job with something else that rewards you, such as music, a short walk before you start, or working alongside someone.
Rest without guilt. If the afternoons are heavy, a short nap is fine. The tiredness is the adenosine signal you've been muffling for years, and it fades as the brain readjusts.
Watch how long it lasts. The withdrawal tiredness fades within about two weeks. If it runs well beyond that, coffee was covering for something else. Low iron or low B12 can feel exactly like needing coffee, and both show up on a blood test.
Life on the other side
The first thing to change is the morning. Without the overnight withdrawal to reverse, waking up stops being something you need help with, and energy comes and goes more gently through the day, without the dip that sends you back to the kettle.
Socially, it takes a little practice. Coffee is woven into how people meet, and saying no can draw a look. Order something else without explaining, suggest a walk in place of a coffee, and keep a caffeine-free option at work. After a few weeks it stops being news.
Pay off the loan
Caffeine never gave you energy of your own. It lent you some against tomorrow and charged interest in sleep, nerves and the morning headache, and every first sip was a repayment dressed up as a lift. Paying it off takes a week of discomfort or a few months of patience, and either way the debt ends. It's also a debt you never have to pass on: a child who never starts has nothing to quit.
So choose your way out today. If it's the fast one, put the date on a quiet weekend. If it's the slow one, weigh tomorrow's coffee, and make it a little smaller than today's. Either way, a morning is coming when the fog lifts on its own.
Looking for a cup to replace it? Best Coffee Alternatives: What's Really in Each Cup — which swaps still carry caffeine, which keep the ritual, and why water wins.
Still lying awake once the coffee is gone? Chronic Insomnia: Why Trying Harder Keeps You Awake — why effort keeps you awake, and how to retrain the bed for sleep.
Know someone who needs a coffee before they can string a sentence together? Send them this. The hard part lasts a week or two, and there are two ways through it.
Disclaimer: This article is general information. For advice about your own health, talk to a qualified health professional. If you are pregnant, trying to conceive or breastfeeding, keep caffeine out altogether.
Affiliate Disclosure: This article contains affiliate links. As an Amazon Associate, All For Life earns from qualifying purchases, at no extra cost to you. We only link to products we would recommend without the commission.
Sources
Nathanson JA (1984). Caffeine and Related Methylxanthines: Possible Naturally Occurring Pesticides. Science 226(4671):184–187. doi.org/10.1126/science.6207592
Wright GA, Baker DD, Palmer MJ, et al. (2013). Caffeine in Floral Nectar Enhances a Pollinator's Memory of Reward. Science 339(6124):1202–1204. doi.org/10.1126/science.1228806
Wikipedia. Friedlieb Ferdinand Runge. en.wikipedia.org
Wikipedia. Caffeine. en.wikipedia.org
James JE, Rogers PJ (2005). Effects of caffeine on performance and mood: withdrawal reversal is the most plausible explanation. Psychopharmacology 182(1):1–8. doi.org/10.1007/s00213-005-0084-6
Sigmon SC, Herning RI, Better W, Cadet JL, Griffiths RR (2009). Caffeine withdrawal, acute effects, tolerance, and absence of net beneficial effects of chronic administration: cerebral blood flow velocity, quantitative EEG, and subjective effects. Psychopharmacology 204(4):573–585. doi.org/10.1007/s00213-009-1489-4
Lin YS, Weibel J, Landolt HP, et al. (2021). Daily Caffeine Intake Induces Concentration-Dependent Medial Temporal Plasticity in Humans: A Multimodal Double-Blind Randomized Controlled Trial. Cerebral Cortex 31(6):3096–3106. doi.org/10.1093/cercor/bhab005
Dawkins L, Shahzad FZ, Ahmed SS, Edmonds CJ (2011). Expectation of having consumed caffeine can improve performance and mood. Appetite 57(3):597–600. doi.org/10.1016/j.appet.2011.07.011
Marcus GM, Rosenthal DG, Nah G, et al. (2023). Acute Effects of Coffee Consumption on Health among Ambulatory Adults. New England Journal of Medicine 388(12):1092–1100. doi.org/10.1056/NEJMoa2204737
Wikipedia. Honoré de Balzac. en.wikipedia.org
Wikipedia. History of coffee. en.wikipedia.org
Wikipedia. Schweigt stille, plaudert nicht, BWV 211. en.wikipedia.org
Wikipedia. Coffee. en.wikipedia.org
Jagim AR, Harty PS, Camic CL (2019). Common Ingredient Profiles of Multi-Ingredient Pre-Workout Supplements. Nutrients 11(2):254. doi.org/10.3390/nu11020254
U.S. Food and Drug Administration. Spilling the Beans: How Much Caffeine Is Too Much? fda.gov
McCusker RR, Goldberger BA, Cone EJ (2003). Caffeine Content of Specialty Coffees. Journal of Analytical Toxicology 27(7):520–522. doi.org/10.1093/jat/27.7.520
U.S. Department of Agriculture. FoodData Central. fdc.nal.usda.gov
National Library of Medicine. DailyMed: Excedrin Extra Strength. dailymed.nlm.nih.gov
National Library of Medicine. DailyMed: NoDoz. dailymed.nlm.nih.gov
Gardiner C, Weakley J, Burke LM, et al. (2023). The effect of caffeine on subsequent sleep: A systematic review and meta-analysis. Sleep Medicine Reviews 69:101764. doi.org/10.1016/j.smrv.2023.101764
Liu C, Wang L, Zhang C, et al. (2024). Caffeine intake and anxiety: a meta-analysis. Frontiers in Psychology 15:1270246. doi.org/10.3389/fpsyg.2024.1270246
Mesas AE, Leon-Muñoz LM, Rodriguez-Artalejo F, Lopez-Garcia E (2011). The effect of coffee on blood pressure and cardiovascular disease in hypertensive individuals: a systematic review and meta-analysis. The American Journal of Clinical Nutrition 94(4):1113–1126. doi.org/10.3945/ajcn.111.016667
U.S. Food and Drug Administration. Pure and Highly Concentrated Caffeine. fda.gov
Juliano LM, Griffiths RR (2004). A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features. Psychopharmacology 176(1):1–29. doi.org/10.1007/s00213-004-2000-x
Evans SM, Griffiths RR (1999). Caffeine Withdrawal: A Parametric Analysis of Caffeine Dosing Conditions. The Journal of Pharmacology and Experimental Therapeutics 289(1):285–294. doi.org/10.1016/s0022-3565(24)38135-2
Weber JG, Ereth MH, Danielson DR (1993). Perioperative Ingestion of Caffeine and Postoperative Headache. Mayo Clinic Proceedings 68(9):842–845. doi.org/10.1016/s0025-6196(12)60691-0
Wikipedia. Caffeine withdrawal. en.wikipedia.org
Meredith SE, Juliano LM, Hughes JR, Griffiths RR (2013). Caffeine Use Disorder: A Comprehensive Review and Research Agenda. Journal of Caffeine Research 3(3):114–130. doi.org/10.1089/jcr.2013.0016
Klevebrant L, Frick A (2022). Effects of caffeine on anxiety and panic attacks in patients with panic disorder: A systematic review and meta-analysis. General Hospital Psychiatry 74:22–31. doi.org/10.1016/j.genhosppsych.2021.11.005
Cornelis MC, El-Sohemy A, Kabagambe EK, Campos H (2006). Coffee, CYP1A2 Genotype, and Risk of Myocardial Infarction. JAMA 295(10):1135–1141. doi.org/10.1001/jama.295.10.1135
Jura YH, Townsend MK, Curhan GC, Resnick NM, Grodstein F (2011). Caffeine Intake, and the Risk of Stress, Urgency and Mixed Urinary Incontinence. Journal of Urology 185(5):1775–1780. doi.org/10.1016/j.juro.2011.01.003
Park J, Lee H, Kim Y, et al. (2023). Effectiveness of Fluid and Caffeine Modifications on Symptoms in Adults With Overactive Bladder: A Systematic Review. International Neurourology Journal 27(1):23–35. doi.org/10.5213/inj.2346014.007
Li M, Wang M, Guo W, Wang J, Sun X (2011). The effect of caffeine on intraocular pressure: a systematic review and meta-analysis. Graefe's Archive for Clinical and Experimental Ophthalmology 249(3):435–442. doi.org/10.1007/s00417-010-1455-1
Morck TA, Lynch SR, Cook JD (1983). Inhibition of food iron absorption by coffee. The American Journal of Clinical Nutrition 37(3):416–420. doi.org/10.1093/ajcn/37.3.416
Zijp IM, Korver O, Tijburg LBM (2000). Effect of Tea and Other Dietary Factors on Iron Absorption. Critical Reviews in Food Science and Nutrition 40(5):371–398. doi.org/10.1080/10408690091189194
Abernethy DR, Todd EL (1985). Impairment of caffeine clearance by chronic use of low-dose oestrogen-containing oral contraceptives. European Journal of Clinical Pharmacology 28(4):425–428. doi.org/10.1007/BF00544361
Jeppesen U, Loft S, Poulsen HE, Brosen K (1996). A fluvoxamine-caffeine interaction study. Pharmacogenetics 6(3):213–222. doi.org/10.1097/00008571-199606000-00003
Swanson JA, Lee JW, Hopp JW, Berk LS (1997). The impact of caffeine use on tobacco cessation and withdrawal. Addictive Behaviors 22(1):55–68. doi.org/10.1016/S0306-4603(96)00023-8
Greenwood DC, Thatcher NJ, Ye J, et al. (2014). Caffeine intake during pregnancy and adverse birth outcomes: a systematic review and dose–response meta-analysis. European Journal of Epidemiology 29(10):725–734. doi.org/10.1007/s10654-014-9944-x
Knutti R, Rothweiler H, Schlatter C (1982). The Effect of Pregnancy on the Pharmacokinetics of Caffeine. Archives of Toxicology Supplement 5:187–192. doi.org/10.1007/978-3-642-68511-8_33
Gleason JL, Tekola-Ayele F, Sundaram R, et al. (2021). Association Between Maternal Caffeine Consumption and Metabolism and Neonatal Anthropometry. JAMA Network Open 4(3):e213238. doi.org/10.1001/jamanetworkopen.2021.3238
Gleason JL, Sundaram R, Mitro SD, et al. (2022). Association of Maternal Caffeine Consumption During Pregnancy With Child Growth. JAMA Network Open 5(10):e2239609. doi.org/10.1001/jamanetworkopen.2022.39609
James JE (2021). Maternal caffeine consumption and pregnancy outcomes: a narrative review with implications for advice to mothers and mothers-to-be. BMJ Evidence-Based Medicine 26(3):114–115. doi.org/10.1136/bmjebm-2020-111432
Stavchansky S, Delgado M, Joshi A, Combs A, Sagraves R (1988). Pharmacokinetics of caffeine in breast milk and plasma after single oral administration of caffeine to lactating mothers. Biopharmaceutics & Drug Disposition 9(3):285–299. doi.org/10.1002/bod.2510090307
Aranda JV, Collinge JM, Zinman R, Watters G (1979). Maturation of caffeine elimination in infancy. Archives of Disease in Childhood 54(12):946–949. doi.org/10.1136/adc.54.12.946
Pollak CP, Bright D (2003). Caffeine Consumption and Weekly Sleep Patterns in US Seventh-, Eighth-, and Ninth-Graders. Pediatrics 111(1):42–46. doi.org/10.1542/peds.111.1.42
Aepli A, Kurth S, Tesler N, Jenni O, Huber R (2015). Caffeine Consuming Children and Adolescents Show Altered Sleep Behavior and Deep Sleep. Brain Sciences 5(4):441–455. doi.org/10.3390/brainsci5040441
Oberstar JV, Bernstein GA, Thuras PD (2002). Caffeine Use and Dependence in Adolescents: One-Year Follow-up. Journal of Child and Adolescent Psychopharmacology 12(2):127–135. doi.org/10.1089/104454602760219162
Bernstein GA, Carroll ME, Dean NW, et al. (1998). Caffeine Withdrawal in Normal School-Age Children. Journal of the American Academy of Child & Adolescent Psychiatry 37(8):858–865. doi.org/10.1097/00004583-199808000-00016
Thompson TR, Hays HL, Kistamgari S, et al. (2025). Pediatric Exposures Associated with Caffeine Energy Products Reported to United States Poison Centers, 2011–2023. Journal of Medical Toxicology 21(2):241–252. doi.org/10.1007/s13181-025-01057-w
James JE, Paull I, Cameron-Traub E, et al. (1988). Biochemical validation of self-reported caffeine consumption during caffeine fading. Journal of Behavioral Medicine 11(1):15–30. doi.org/10.1007/BF00846166
Scher AI, Stewart WF, Lipton RB (2004). Caffeine as a risk factor for chronic daily headache. Neurology 63(11):2022–2027. doi.org/10.1212/01.WNL.0000145760.37852.ED
Bigal ME, Lipton RB (2009). Overuse of acute migraine medications and migraine chronification. Current Pain and Headache Reports 13(4):301–307. doi.org/10.1007/s11916-009-0048-3
Drake C, Roehrs T, Shambroom J, Roth T (2013). Caffeine Effects on Sleep Taken 0, 3, or 6 Hours before Going to Bed. Journal of Clinical Sleep Medicine 9(11):1195–1200. doi.org/10.5664/jcsm.3170
Landolt HP, Werth E, Borbély AA, Dijk DJ (1995). Caffeine intake (200 mg) in the morning affects human sleep and EEG power spectra at night. Brain Research 675(1-2):67–74. doi.org/10.1016/0006-8993(95)00040-w
Wikipedia. Decaffeination. en.wikipedia.org
Wikipedia. Break (work). en.wikipedia.org
Randolph DD, O'Connor PJ (2017). Stair walking is more energizing than low dose caffeine in sleep deprived young women. Physiology & Behavior 174:128–135. doi.org/10.1016/j.physbeh.2017.03.013
Volkow ND, Wang GJ, Logan J, et al. (2015). Caffeine increases striatal dopamine D2/D3 receptor availability in the human brain. Translational Psychiatry 5(4):e549–e549. doi.org/10.1038/tp.2015.46