Caffeine is the most widely consumed pharmacologically active substance in Europe, and until 2015 there was no EU-wide statement of how much of it was fine. Then EFSA published one, and it is refreshingly specific.
The thresholds
For healthy adults who are not pregnant:
- Up to 400 mg per day, from all sources combined, does not raise safety concerns.
- Single doses up to 200 mg do not raise safety concerns — including when taken less than two hours before intense exercise in normal conditions.
For pregnant women, habitual intake up to 200 mg per day does not raise safety concerns for the foetus.
Note the phrasing throughout: does not give rise to safety concerns. This is a risk assessment, not a recommendation. EFSA is not suggesting anyone consume 400 mg; it is saying that doing so is not where harm begins.
Translating that into cups
Caffeine content varies enormously with bean, roast, grind and method, so these are ranges rather than constants:
| Drink | Roughly |
|---|---|
| Espresso (single) | 60–80 mg |
| Filter coffee, 200 ml | 90 mg |
| Instant coffee, 200 ml | 60–80 mg |
| Black tea, 220 ml | 45 mg |
| Green tea, 220 ml | 30 mg |
| Energy drink, 250 ml | 80 mg |
| Cola, 330 ml | 35 mg |
Four filter coffees sit near the daily figure. A very large takeaway filter coffee can approach the 200 mg single-dose figure on its own, which is the one piece of this that surprises people — the ceiling on a single serving is reached by one cup, if the cup is big enough.
The sources that get missed
All sources count, and caffeine arrives in places the label does not emphasise: cola and some other soft drinks, energy drinks and shots, pre-workout powders, some weight-loss and “focus” supplements, green tea extract, guarana, and dark chocolate in modest amounts. Anyone stacking a pre-workout onto a normal coffee day can clear 400 mg without ever drinking a fourth cup.
The ceiling is on caffeine, not on coffee. The arithmetic includes the things that do not taste like coffee.
Sleep, which is the real constraint for most people
The safety threshold and the useful threshold are different numbers. Caffeine’s half-life in a healthy adult is roughly five hours, with wide variation — so a 16:00 double espresso still has meaningful caffeine circulating at bedtime, even in someone who falls asleep fine. Sleep architecture is affected before sleep onset is, which is why “coffee doesn’t keep me awake” and “coffee is costing me sleep quality” can both be true.
If sleep is the thing you are trying to fix, the lever is timing rather than total: a cut-off in the early afternoon changes more than dropping a cup.
Who should be more careful than the numbers suggest
EFSA’s figures are for healthy adults. They are not the right frame for people with cardiac arrhythmias, anxiety disorders, uncontrolled hypertension, or on medications that interact with caffeine metabolism — and adolescents, whom EFSA treats separately and more conservatively, are not covered by the adult number at all.
And there is genetic variation in how fast caffeine is cleared that no guideline can capture. Someone who feels wired for six hours after one cup is not imagining it, and has a good reason to ignore the headline figure entirely.
