Caffeine provides powerful stimulant effects on the central nervous system, heart, muscles, and centers that control blood pressure, making us feel more alert and energetic.
As such, many of us use caffeine to prevent fatigue and help us get through a long busy day, improve our concentration and productivity, or to help us wake up in the morning.
Although caffeine has some much-desired effects, unfortunately, they come at a price. Adverse side effects from caffeine are common, and the more you consume, the more likely you are to experience them - so you might want to hold back on that fifth cup of coffee!
Side Effects of Caffeine
Besides anxiety, jitters, and energy crashes, consuming too much caffeine can increase the risk of negative effects such as caffeine-induced nausea, digestive discomfort, upset stomach, and other symptoms.
People with caffeine sensitivity are more likely to experience symptoms like coffee nausea, even at lower doses of caffeine.
This article will examine why caffeine might make you feel sick and how to avoid it...
Key Takeaways
- Yes—caffeine can cause nausea in sensitive people, especially fasted, dehydrated, or at high doses.
- Contributors include gastric acid, anxiety, and rapid GI motility; dose and timing matter.
- Strategies: eat first, hydrate, reduce dose, choose gentler delivery, pair with calming nutrients.
- Consider alternative energy supports if nausea persists.
Excess Stomach Acid Can Cause Stomach Pain
Caffeine stimulates your digestive system, increasing stomach acid production and the secretion of digestive fluid, causing it to work faster and produce more stomach acid than necessary. (1).
Natural Acids Irritate the Stomach Lining
Coffee also contains natural acids such as citric acid and acetic acid, which can further irritate the stomach lining and contribute to digestive issues. If you have an empty stomach, there is nothing for these acids to digest, which can cause nausea, abdominal pain, and bloating.
Acid Reflux
Caffeine may also increase the likelihood of acid reflux or heartburn in caffeine sensitive individuals because it relaxes the lower esophageal sphincter, a ring of muscle that separates your esophagus and your stomach.
If this doesn’t close tightly, it allows stomach acid to flow up into your esophagus, resulting in a painful burning sensation and nausea. Acid reflux can also cause gastrointestinal symptoms such as bloating and discomfort. In some cases, acid reflux and caffeine can also lead to heart palpitations. (2)
Drinking Coffee Acts as a Diuretic
Regular coffee drinkers will know about the laxative effects of caffeine (although they may be reluctant to share this side effect!). A few sips of coffee can get you heading straight for the bathroom because it is a diuretic. (3).
This means it stimulates the removal of water from the body, drawing it out of the bloodstream and into the digestive system so it can be excreted. Because caffeine triggers fluid loss, it is important to stay hydrated to help counteract these effects.
Consuming too much of a diuretic like coffee can lead to nausea and diarrhea, but staying hydrated can help prevent these symptoms.
Additional Ingredients and Coffee Induced Nausea
Most caffeinated beverages, such as coffee and energy drinks, are combined with sugar, artificial sweeteners, or milk, which can contribute to nausea. Adding milk or creamer to coffee may help reduce harsh acidity or lower acidity and nausea for some people, making it more tolerable on the stomach.
But if you’re partial to a sweet, milky coffee and find yourself feel sick afterward, you may be lactose-intolerant or consuming too much sugar. For those with sensitivities or allergies, plant based milk is a gentler alternative to traditional dairy and may help reduce stomach irritation.
Digestive Issues
Artificial sweeteners are especially bad for your stomach because they can upset the gut’s delicate microbiome and promote the growth of harmful bacteria, resulting in gastrointestinal distress. (4)
These ingredients can also leave your stomach unsettled after drinking coffee, leading to symptoms like queasiness or discomfort. In some cases, artificial sweeteners may contribute to coffee related nausea, especially for those sensitive to certain additives.
Coffee Types and Nausea
Not all cups of coffee are created equal when it comes to how your stomach reacts. The type of coffee you choose can play a big role in whether you experience coffee induced nausea, acid reflux, or other digestive issues.
Lights Roasts versus Dark Roasts
Different coffee types vary in both acidity and caffeine content, which are two major factors that can trigger stomach irritation. For example, light roasts generally have higher acidic compounds compared to dark roasts, which can lead to more stomach discomfort for those with sensitive stomachs. (5, 6)
If you find yourself feeling nauseous after drinking coffee, you might want to try switching to a dark roast, which tends to be lower in acidity and gentler on the stomach lining.
Cold Brew Coffee and Decaf
Cold brew coffee is another option worth considering. Thanks to its unique brewing process, cold brew coffees are typically less acidic than regular coffee, making them a popular choice for people prone to acid reflux or stomach upset.
Decaffeinated coffee is also a good alternative if you suspect that caffeine content is the main culprit behind your digestive issues, as it contains much less caffeine but still delivers the familiar coffee flavor.
Ultimately, experimenting with different coffee types — whether it’s cold brew, decaf, or a darker roast — can help you find a brew that doesn’t irritate your stomach or trigger nausea.
Paying attention to how your body responds to various coffees is key to enjoying your morning cup without the unwanted side effects. (7)
How To Prevent Side Effects From Caffeine
Despite the unpleasant side effects of caffeine, it is still an essential substance for over 80% of the world population. (8)
Fortunately, there are ways to minimize these effects while reaping caffeine’s benefits. Certain strategies can help prevent and reduce nausea caused by caffeine, making coffee consumption more tolerable.
Monitoring your caffeine intake and coffee intake is important to avoid symptoms like nausea and stomach discomfort. Be aware of the risk of excess caffeine and caffeine overdose and recognize its symptoms, such as severe nausea and vomiting.
Warning about Medications
Additionally, medication interactions can increase the risk of side effects from coffee consumption, so it is important to consider any medications you are taking when drinking coffee.
1. Avoid Coffee on an Empty Stomach
As discussed earlier, consuming caffeine on an empty stomach puts you at a higher risk of nausea. To avoid this, eat before drinking coffee or any other caffeinated product, so your stomach acids aren’t just sitting there.
Anything will do! But foods that are high in protein are best because they slow the rate of digestion and help prevent nausea or reduce the feeling of nausea. (9)
2. Drink plenty of water
While a small amount of caffeine will not dehydrate you, it still acts as a diuretic and removes water and important electrolytes from the body.
Drinking water replaces the fluids that you have lost, dilutes stomach acid to dampen the harmful effects, and helps keep your electrolytes up. Drinking cold water can also be especially refreshing and help with hydration after coffee.
3. Drink black coffee
If you get your daily caffeine fix through a sweet, milky coffee but suffer from nausea after, you might want to reconsider your choices. Try drinking coffee black and ditching the sugar - it might not taste as good, but nor does acid reflux!
Plant-based milks are easier to digest and easier on the stomach, so you could always experiment with different milk options.
4. Cut down to avoid caffeine overdose
This may sound obvious, but if you are suffering from the side effects of caffeine, it might be time to look at your coffee intake and monitor how much caffeine you are consuming. The more caffeine you consume, the more likely you are to feel nauseous - simple!
Recommended Caffeine Intake
The Dietary Guidelines for Americans suggest a safe upper limit of 400mg of caffeine a day, approximately 3-5 cups. Remember energy drinks, tea, cola and other drinks can also contain caffeine. If you're pregnant or breastfeeding, obviously the rules are different. Likewise, one person's caffeine tolerance can be much higher or lower than another's. (10)
Find your limit on how much caffeine you can consume before you feel sick. For some, this may just be one cup of coffee; for others, it may be four.
Some people choose to cut coffee with water or milk to reduce how much caffeine they get per cup. Replacing or rotating coffee with other hot drinks like herbal tea can also help lower your intake while increasing your hydration.
5. Take a caffeine supplement instead
Performance Lab Caffeine 2 provides a moderate dose of caffeine that effectively boosts mental and physical energy, focus, concentration, and productivity.
Combining natural caffeine with other complementary substances, such as L-theanine and L-tyrosine, it provides cleaner and healthier stimulation benefits with fewer side effects. With a modest 50mg of caffeine per capsule, it allows you to control your dose.
Caffeine supplements may help maintain energy levels throughout the day without the negative side effects often associated with coffee. Adjusting your caffeine source in this way can also enhance your overall coffee experience by reducing jitters and crashes.
Great stuff! I won't take caffeine without the L-theanine. This is the perfect blend and also has added B vitamins!Cindy S
Take Home Thoughts
Caffeine is a popular substance consumed worldwide for its positive effects on mood, energy, focus, and productivity. However, these are often accompanied by numerous unwanted side effects, such as nausea.
Caffeine can cause nausea by acting as a diuretic as well as stimulating an overproduction of stomach acid, which can also leak into the esophagus and trigger acid reflux. The way you make coffee can also influence whether it causes nausea, as certain brewing methods may result in higher acidity or stronger effects on the stomach.
Caffeinated products also often contain added sugars or milk, which can further compound feelings of nausea.
To reduce the risk of side effects from caffeine, always ensure you have a full stomach before consuming it, drink plenty of water, ditch the cow’s milk and sugar or opt for a caffeine supplement with much fewer side effects.
References
- Boekema, J., Samsom, M., van Berge Henegouwen, G. P., & Smout, A. J. P. M. (1999). Coffee and gastrointestinal function: Facts and fiction: A review. Scandinavian Journal of Gastroenterology, 34(230), 35–39.
- Cohen, S., & Booth, G. H., Jr. (1975). Gastric acid secretion and lower-esophageal-sphincter pressure in response to coffee and caffeine. New England Journal of Medicine, 293(18), 897–899.
- Marx, B., et al. (2016). Mechanisms of caffeine-induced diuresis. Medecine Sciences (M/S), 32(5), 485–490.
- Suez, J., et al. (2015). Non-caloric artificial sweeteners and the microbiome: Findings and challenges. Gut Microbes, 6(2), 149–155.
- Olechno, E., Puścion-Jakubik, A., Zujko, M. E., & Socha, K. (2021). Influence of various factors on caffeine content in coffee brews. Foods, 10(6), 1208.
- Birke Rune, C. J., Giacalone, D., Steen, I., Duelund, L., Münchow, M., & Clausen, M. P. (2023). Acids in brewed coffees: Chemical composition and sensory threshold. Current Research in Food Science, 6, 100485.
- 9 Impressive Benefits of Cold-Brew Coffee (Plus How to Make It). Healthline. https://www.healthline.com/nutrition/cold-brew-coffee-benefits
- Heckman, M. A., Weil, J., & De Mejia, E. G. (2010). Caffeine (1,3,7-trimethylxanthine) in foods: A comprehensive review on consumption, functionality, safety, and regulatory matters. Journal of Food Science, 75(3), R77–R87.
- Is It OK To Drink Coffee on an Empty Stomach? Cleveland Clinic. https://health.clevelandclinic.org/coffee-on-empty-stomach
- 9 Reasons Why (the Right Amount of) Coffee Is Good for You. Johns Hopkins Medicine. https://www.hopkinsmedicine.org/health/wellness-and-prevention/9-reasons-why-the-right-amount-of-coffee-is-good-for-you
