Sudden Sensitivity to Caffeine? 6 Potential Causes

Kayla Newnam
Sudden Sensitivity to Caffeine? 6 Potential Causes

Is It Possible To Suddenly Develop a Sensitivity to Caffeine?

Are you a habitual coffee drinker or find yourself grabbing energy drinks? According to a study, 85% of the United States population consumes at least one beverage that contains caffeine daily. You may have found that you developed a sudden sensitivity to caffeine or built a tolerance. Caffeine can affect everyone differently and it can be affected by a variety of factors. We are going to share about the different levels of sensitivity, causes and how to combat a sudden caffeine sensitivity. 

Are There Different Levels of Caffeine Sensitivity?

There are definitely different levels of caffeine sensitivity and it can change depending on several factors. You may find yourself turning down an afternoon cup of coffee due to fear of not being able to sleep while someone else drinks coffee right before bed and experiences zero difficulties. According to research, there do seem to be people that have higher and lower levels of sensitivity to caffeine. Let’s learn about the two major sides of the coin so you can identify which one you are. 

Hyposensitivity vs. Hypersensitivity: What’s the Difference?

If you drink multiple cups of coffee per day or ask for extra shots of espresso at your local coffee shop because you don’t feel the effects of caffeine, you may be hypo-sensitive.  Some of us may experience an increase in heart rate, headaches, feelings of anxiousness, and/or difficulty sleeping after a few sips or a cup of coffee may be hypersensitive to caffeine. Our ability to metabolize caffeine can be delayed or expedited based on our genes, smoking of cigarettes, pregnancy, stress, and more. Aside from our body being able to clear coffee, the amount of caffeine we are consuming can vary depending on source of caffeine, types of coffee beans, water to coffee ratio and more.

Average Sensitivity

Although the level of sensitivity to caffeine varies, there is also an average sensitivity. According to the FDA the recommended daily caffeine intake is around 400 mg of caffeine per day. For coffee, this is equivalent to around 4 cups whereas one serving of an energy drink can contain 80 - 400mg of caffeine. If you aren’t sure where you sit on the scale of sensitivity, we recommend making note of how you feel consuming different amounts of caffeine and making choices based on that. You can also test your other health metrics like magnesium, sodium, calcium + more using Vessel’s at-home wellness tests! Click here to sign up today!

What Causes Sudden Caffeine Sensitivity

How caffeine impacts you is determined by how quickly your body metabolizes caffeine. This is what can drive high tolerance levels or cause hypersensitivity to caffeine. So, what impacts your body's ability to break down caffeine? 


There are studies that show the impact of medications on the half life of caffeine. Most of these increase the half life of caffeine which means you will experience the effects of caffeine for a longer duration of time. For example, there’s a medication used for treating depression that causes the half life of caffeine to go from 5 to 31 hours. This can happen when the medication causes a delay in the clearance of caffeine from the body. We recommend speaking with your doctor if you have any concerns around how caffeine may affect the medication you are taking. 


How do we metabolize caffeine? 90% of caffeine is cleared by CYP1A2, which is present in our liver. There are different positions for CYP1A2, meaning different genes that can dictate whether you are able to rapidly or slowly clear caffeine. According to research, 46% of the population are known as rapid metabolizers of caffeine while 54% will metabolize caffeine slowly solely on CYP1A2. There are other enzymes and factors regarding genes that can also affect the rate that we metabolize caffeine. 


The normal half life of caffeine is anywhere from 2.5 hours to 5 hours on average. Towards the end of pregnancy, in the third trimester the half life ranges from 11.5 hours to 18 hours. When your body can’t metabolize caffeine it will build up within your system and the fetus. This is one reason it’s recommended to not consume caffeine during pregnancy. However, within a few weeks following the birth of the baby, your caffeine metabolism will go back to normal. Always consult with your doctor before making any changes. 

Birth Control

You may be right if you feel like during your cycle your sensitivity to caffeine changes. For one, during the luteal phase of your cycle caffeine metabolism decreases. When you are taking oral contraceptives it also affects the half life of caffeine by nearly double, especially during that luteal phase. This is another reason you should track your cycle and be cautious of the amount of caffeine you are ingesting during that time. 

Reduced Tolerance After a Break

Have you ever gone without caffeine for a period of time and now you are sensitive to caffeine? This can happen due to your body no longer having the tolerance for caffeine that it once did. When introducing caffeine back into your body, you’ll want to make gradual increases and let your body rebuild a tolerance to avoid feelings of anxiety, jitters, difficulty sleeping, etc. 

How Can I Combat Caffeine Sensitivity?

Reduce Your Caffeine Consumption

When we think about lowering caffeine consumption, coffee is generally the first consideration. This is a great place to start, but it’s important to know that other beverages like energy drinks, pre-workout powders, weight loss and herbal supplements, soda, tea, and other beverages also contain varying amounts of caffeine. When picking a beverage, try to select one that is caffeine free and decrease the amount of caffeinated beverages over time. 

Try Decaf

Decaf coffee is generally 95% caffeine free, this is a big improvement and a great way to combat caffeine sensitivity. If you aren’t ready to completely remove caffeinated coffee, ask for a “half-caff” coffee or make sure you review labels on food and beverages that may contain caffeine and choose the option with the least amount of caffeine. 

Drink Tea Instead of Coffee

One quick way to cut down on your caffeine intake is by drinking tea. Although some tea has caffeine, it’s typically closer to 40 mg versus a cup of coffee or energy drink which contains over 95 mg of caffeine on average. This could be an easy swap for a mid-day cup of coffee or a great solution for a pick me up without the jittery feeling if you are sensitive to caffeine. 

The Bottom Line

The bottom line is that caffeine comes in various forms and levels of potency. As humans, we are all unique and affected differently by caffeine. Whether you find yourself being sensitive to caffeine or having a high tolerance for caffeine, it’s likely due to the amount of caffeine you drink and other factors. There may be times in your life where you find yourself more sensitive and need to pull back on caffeine and search for an alternative. If you find yourself in this situation, reach out to the Vessel Nutrition Coaches and they will be happy to offer some caffeine free options for you!