How Long Does Caffeine Last? (Duration of Effects)

The effects of caffeine typically last between 4 and 6 hours, but it remains in your system for up to 10.

April 27, 2024
A collection of caffeinated beverages neatly arranged on a table.

On average, it takes the body about 10 hours to process and metabolize all the caffeine in your system.

The total duration of caffeine will change depending on the individual and their ability to metabolize caffeine. Some people metabolize more quickly (5 to 6 hours), others slower (up to 12 hours).

People who metabolize caffeine too quickly may experience the dreaded caffeine crash — leaving you feeling tired and even worse than before as your body adjusts.

Others metabolize slowly — leading to feelings of anxiety, overstimulation, and difficulty sleeping.

That being said, most people experience peak effects around 45 minutes to an hour after drinking coffee, which lasts between 1 and 2 hours before tapering off.

How Long Does Caffeine Last?

We’ve broken down the effects of caffeine into a timeline, highlighting the short-term and long-term impacts on physical and cognitive performance.

The First Hour (Onset)

Caffeine is a pretty fast-acting stimulant, so it reaches your bloodstream quickly once you take your first few sips of tea or coffee.

10 minutes: The caffeine starts to affect your adenosine receptors, making you feel more alert and awake [1]. Once the caffeine reaches your brain, you’ll start to feel that typical buzz of alertness and awakeness that people associate with a good coffee. Some people may also experience the “caffeine jitters” as it affects their central nervous system, causing them to experience tremors or shakes in their body. 

30 minutes: Caffeine and the chlorogenic acid in coffee work together to curb your appetite, and your body begins to burn fat more easily [2].

1 hour: After 60 minutes of blocking your adenosine receptors, the change in the adenosine levels results in increased production of dopamine, boosting your mood

Peak Effects (2–3 Hours In)

Caffeine's peak effects kick in within about 1 hour after drinking. This effect usually remains in full force for about an hour or two before it starts to fade out.

Peak effects of caffeine include: 

  • Increased breathing and heart rate
  • Increased physical energy
  • Increased mental alertness
  • A “refreshed” feeling

The Halfway Point (3–5 Hours In)

Once you’ve experienced its initial effects, the caffeine still lingers in your system even though you might not feel it as intensely as when you first had your drink of coffee. This leads to a feeling of sustained energy and focus over the next couple of hours until you reach the halfway point.

The half-life of caffeine is between 5 and 6 hours after ingestion. 

To put this into perspective, the average cup of coffee contains around 100 mg of caffeine. If you’re using robusta coffee, know that it has a higher caffeine content than arabica beans. Five hours after drinking it, you will have half the amount of caffeine in your system, so 50mg is still providing its effects. 

This is often why some people find it hard to sleep even though it’s been a while since they had a caffeinated beverage. For example, you get home at 5 PM from work and have a cup of tea or coffee as a pick-me-up. By 10 PM, when you might be thinking about going to bed, half of that caffeine is still working, which may make it tricky to doze off. 

While the initial effects of caffeine can be beneficial, some individuals may experience a caffeine crash a few hours after consumption. This happens when the body becomes highly efficient at metabolizing caffeine, leading to a rapid drop in energy levels as the adenosine that was previously blocked by the caffeine floods back in. 

One potential strategy to mitigate this caffeine crash is to drink beverages that contain both caffeine and L-theanine, such as tea. The L-theanine helps to slow the release of caffeine into the system, providing a more gradual and sustained energy boost [3].

The Fade-Out & After-Effects (5–10 Hours In)

After 10 hours, the caffeine should have left your system completely. However, it is worth noting that this is only per drink. If you drank a cup of coffee 10 hours ago but then had another one 3 hours later, you’d have another 3 hours to go until it is all out of your system. The same can be said for larger doses of caffeine, so those of you who like your coffee extra strong, like Cafely’s HaNoi or BanMe, may need more time to process all of the caffeine. 

To add to this, there is the nasty subject of caffeine withdrawal, which usually kicks in between 12 and 14 hours after having none of this stimulant. This means that by the time your 10 hours are up, you’re probably ready to get yourself another cup. 

Caffeine Affects Everyone Differently

The effect of caffeine and how long it lasts can vary from person to person. 

If you drink a lot of caffeinated beverages in a short space of time or stronger ones like Vietnamese coffee, you will feel more of an effect (and also some side effects). At the same time, those who don’t regularly drink tea or coffee will feel more of its effects than daily drinkers, as their bodies haven’t built up as much of a caffeine tolerance.

Some people are simply more sensitive to caffeine too. They may lack some of the enzymes used to metabolize caffeine, which can make it hit harder and last longer.

Caffeine: Tea vs. Coffee

It may surprise you to learn that tea leaves actually contain more caffeine than coffee beans, at 3.5% compared to around 1-2%. However, when it comes to preparing the drink, the hotter temperature, steeping methods, and quantity of tea leaves needed for a brew means that a cup of black tea has around half the caffeine as a similarly sized cup of black coffee [4]. 

The caffeine found in tea and coffee is exactly the same, and so both work through your system in a similar timeframe. The main difference between the two is the fact that tea naturally contains the amino acid L-theanine [3]. L-theanine works synergistically with caffeine, helping it to have a slower release than acting almost instantaneously as it does in coffee. This is why tea drinkers often won't get the same buzz as their coffee-drinking counterparts.

FAQs: Caffeine Duration & Effects

Do you have more questions about the duration and effects of caffeine? Below are some of the most commonly asked questions about the topic.

1. How long does the coffee effect last?

The duration of coffee’s effects depends on two factors: firstly, the amount and strength of coffee consumed, and secondly, your caffeine tolerance. The higher the amount of caffeine in your system, the more effect you will feel, although this can also lead to uncomfortable side effects, like trembling, headaches, and anxiety. Also, the more your body is used to ingesting caffeine, the more you will need to consume to get an effect. 

2. How does caffeine keep you awake?

Caffeine is considered a stimulant, meaning that it’s a type of drug that promotes alertness. One of the ways it does this is by inhibiting your body’s adenosine receptors, which help to promote sleepiness. 

3. How long does coffee keep you awake?

This depends completely on the person and their circumstances, but the effects of caffeine are more profound when you have just had some. Therefore, you’ll feel the most alert and awake during the first hour after drinking it, with this gradually decreasing over time. 

4. How long does caffeine from tea last?

Tea, on average, has around half of the caffeine content of coffee, but it still takes the same amount of time to go through your system. The only difference lies in the dosage. A cup of tea with 50mg of caffeine will have a half-life of 25mg 5 hours after drinking. 

Again, this depends on the type and amount of tea consumed. 

5. What time should you stop drinking caffeine?

There is no clear-cut answer to this question, as everyone is different and has a different caffeine tolerance. If you’re having trouble sleeping and you feel caffeine consumption may be the cause, consider implementing a “caffeine curfew.” Try having your last cup of tea or coffee an hour earlier and keep on pushing it back an hour until you find the balance that works for you. You could also try a coffee with a lower caffeine content, such as our 100% arabica DaLat coffee.


  1. Ribeiro, J. A., & Sebastião, A. M. (2010). Caffeine and adenosine. Journal of Alzheimer’s Disease: JAD, 20 Suppl 1(20), S3-15.
  2. Rojas-González, A., Figueroa-Hernández, C. Y., González-Rios, O., Suárez-Quiroz, M. L., González-Amaro, R. M., Hernández-Estrada, Z. J., & Rayas-Duarte, P. (2022). Coffee Chlorogenic Acids Incorporation for Bioactivity Enhancement of Foods: A Review. Molecules, 27(11), 3400.
  3. Giesbrecht, T., Rycroft, J. A., Rowson, M. J., & De Bruin, E. A. (2010). The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness. Nutritional Neuroscience, 13(6), 283–290.
  4. Komes, D., Horžić, D., Belščak, A., Kovačević Ganić, K., & Baljak, A. (2009, June). Determination of Caffeine Content in Tea and Maté Tea by Using Different Methods [Review of Determination of Caffeine Content in Tea and Maté Tea by Using Different Methods].‌