How long does it take to digest coffee? (3 factors)

In this brief guide, we will answer the question,’ How long does it take to digest coffee?’. Coffee digestion is a common concern for frequent consumers. This owes to the high acidic and caffeine content in the beverage. We will consider the variable factors that impact the digestion of coffee in the human body.

How long does it take to digest coffee?

Caffeine is not known to undergo significant first-pass metabolism and generally reaches peak plasma concentrations within 30 to 120 minutes after administration, although some individuals may fall outside of this range. 

When consumed with food and perhaps some beverages, absorption may be slower compared to ingestion of caffeine alone on an empty stomach presumably due to a delay in gastric emptying.

The vast majority of caffeine elimination occurs mainly by renal excretion in urine (~ 85-88%). The elimination half-life is variable with an average of approximately 3-6 hours in healthy humans. However, these values can vary substantially from 2.3 to 9.9 hours. (1)

What is the nutritional value of coffee?

The nutritional value of coffee, Considering the example of a 1 cup of espresso coffee weighing approximately 100 g, its composition can be summarized as follows:

  • Energy content: Between 0 to 2 kcal
  • Fat: 0.2g
  • Protein: 0.1g
  • Water: 97.8g
  • Caffeine: 40mg

It’s worth noting that 1 cup of regular coffee typically contains about 2 grams of coffee, indicating a well-balanced composition.

Coffee is not just known for its caffeine content but also contains a complex mixture of compounds that have various physiological effects. In fact, there are approximately 1000 described phytochemicals found in coffee. 

Some notable examples include phenols like chlorogenic and caffeic acid, lactones, diterpenes such as cafestol and kahweol, as well as niacin and trigonelline, which is a precursor to vitamin B3. Additionally, coffee is also rich in vitamin B3, magnesium, and potassium. (2)

How does coffee digest?

As for any other food or beverage, the gastrointestinal tract is the first body system that gets in contact with coffee, and local effects do occur. Of course, other gastrointestinal effects occur after absorption of the different coffee components. (3)

Caffeine has rapid and complete (i.e., 99%) absorption from the small intestine after oral administration in humans due to its weakly basic nature, favoring an unionized/lipophilic state in the more basic environment of the small intestine.

There it may more easily partition into the lipid bilayer of cells, as compared to the acidic environment of the stomach where it is more ionized and less lipophilic 

Caffeine is distributed throughout the body after being absorbed from the gastrointestinal tract (the small intestine in particular), entering all tissues via cell membranes and entering intracellular tissue water. (1)

What factors can affect  coffee digestion?

On average, the half-life of caffeine is approximately 3.7 hours, although it can range from 2 to 10 hours. The duration can vary based on various factors, both internal and external. 

For instance, nicotine users tend to experience an accelerated metabolic speed of caffeine, with an increase of 30-50%. Conversely, pregnant women and women taking oral contraceptives may exhibit a decrease in caffeine metabolism.

Furthermore, there are significant interindividual differences in sensitivity to caffeine, primarily influenced by genetic variations. These genetic factors contribute to varying responses and tolerances to caffeine among individuals. 

Therefore, the effects and duration of caffeine can differ from person to person based on their genetic makeup.(4)

What are the effects of caffeine on the body?

Caffeine acts as a stimulant, causing an increase in heart rate, breathing rate, and mental alertness by triggering the secretion of cortisol and adrenaline in the body. This stimulation also affects the neural system, enhancing focus and promoting attentiveness. 

Moreover, coffee contains dopamine, which acts as a brain booster, helping to improve concentration and alertness. In addition to its stimulating effects, coffee has shown potential in preventing degenerative disorders, partly due to its neurostimulating, antioxidant, and anti-inflammatory properties. 

Coffee consumption is associated with a significant decrease in the risk of death related to heart disease, respiratory disease, stroke, injuries and accidents, diabetes, and infections. These beneficial effects may be attributed to the various bioactive compounds present in coffee. (1, 5)

What happens if you consume too much coffee?

Consuming an excessive amount of coffee can have negative effects on the body, impacting both physical and mental well-being. While caffeine initially provides a stimulating boost, it can eventually lead to crashes, causing sudden fatigue and sleepiness in certain individuals.

Coffee’s ability to interfere with adenosine, a chemical that helps prevent fatigue, can induce anxiety in some people. This anxiety is a result of caffeine’s influence. 

Excessive caffeine consumption can also lead to symptoms such as fatigue, nausea, and even contribute to the development of caffeine-induced anxiety disorder. 

When approximately 1000 mg of caffeine is consumed per day, manifestations like nervousness, jitteriness, and nausea can occur. It is important to be mindful of caffeine intake to avoid these adverse effects on the body. (1, 4, 5)

Other FAQs about Coffee which you may be interested in.

How much sodium is in a cup of coffee?

How to dissolve Cinnamon Powder in Coffee?


In this brief guide, we answered the question,’ How long does it take to digest coffee?’. Coffee digestion is a common concern for frequent consumers. This owes to the high acidic and caffeine content in the beverage. We will consider the variable factors that impact the digestion of coffee in the human body.


  1. Willson, C.  The clinical toxicology of caffeine: A review and case study. Toxicology Reports. 2018.
  2. Cano-Marquina, A., Tarín, J. J., & Cano, A.  The impact of coffee on health. Maturitas, 75(1), 7–21. 2013.
  3. riondo-DeHond A, Uranga JA, Del Castillo MD, Abalo R. Effects of Coffee and Its Components on the Gastrointestinal Tract and the Brain-Gut Axis. Nutrients.13(1):88.  2020.
  4. Snel, J., & Lorist, M. M. Effects of caffeine on sleep and cognition. Human Sleep and Cognition – Clinical and Applied Research, 105–117. 2011.
  5. Farah, Adriana.  Nutritional and health effects of coffee. 10.19103/AS.2017.0022.14. 2018.

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