Coffee can temporarily improve alertness, but it cannot replace sleep. Here is what to know about caffeine, serving sizes and timing.
How does caffeine reduce tiredness?
Caffeine blocks adenosine receptors in the brain, which can temporarily reduce sleepiness. It does not make up for lost sleep. Individual sensitivity and habitual consumption also influence the response. [3]
How quickly does caffeine work?
According to Germany’s Federal Institute for Risk Assessment (BfR), stimulant effects may begin about 15–30 minutes after consumption and last for several hours. Their duration varies between individuals. [2]
How much caffeine is in drinks?
The approximate values below come from EFSA. Actual caffeine content varies with beans, serving size and preparation; these are not measurements of products sold in our shop. [1]
about 80 mg
about 90 mg
about 50 mg
Which caffeine amounts provide general guidance?
For healthy adults, EFSA considers single doses up to 200 mg and totals up to 400 mg spread throughout the day, from all sources, not to raise safety concerns. During pregnancy and breastfeeding, the lower reference amount is a total of up to 200 mg a day from all sources. [1] [2]
These are not recommended drinking amounts or daily targets. Individual tolerance may be lower. Seek medical or pharmaceutical advice if you have a medical condition, take medication or experience symptoms; general reference amounts do not guarantee individual safety. [2]
Coffee and sleep
Even 100 mg can affect sleep in some adults, especially close to bedtime. [1] Coffee should not be used to keep masking a lack of rest.
Enjoying a mindful coffee break
Explore our coffee beans, E.S.E. pods and coffee machines. Learn about Arabica vs Robusta.
Frequently asked questions
Does coffee cure tiredness?
No. It may improve alertness temporarily but does not replace sleep. [1]
How quickly does caffeine work?
Effects may begin after about 15–30 minutes. [2]
Does espresso have more caffeine than filter coffee?
Total caffeine depends on serving size and preparation. Espresso is often more concentrated per millilitre; the EFSA example portions above therefore have different volumes. [1]
Can coffee affect sleep?
Yes. Even 100 mg can affect some adults, especially when consumed close to bedtime. [1]
Sources and context
General information for adults, not individual medical advice. These sources explain caffeine effects and assessed intake amounts, not the measured caffeine content of our products.
