Is it okay to drink coffee on an empty stomach?

October 14, 2025 •

5 min read

According to the National Coffee Association, up to 9 out of 10 coffee drinkers begin their day with a cup of coffee, often before eating anything. While this morning ritual is beloved, for some, drinking coffee on an empty stomach can trigger a range of uncomfortable symptoms.

Quick Summary

Drinking coffee on an empty stomach is generally safe for most healthy people, but individual tolerance varies. Some may experience digestive issues, hormonal spikes, or intensified caffeine effects, which can be managed with mindful consumption.

Key Points

Individual Tolerance: Whether drinking coffee on an empty stomach is safe depends on your body's sensitivity and health conditions, with many people experiencing no issues.
Digestive Risks: For sensitive individuals, consuming coffee without food can increase stomach acid, potentially leading to heartburn, acid reflux, or other digestive discomfort.
Faster Absorption: On an empty stomach, caffeine is absorbed more rapidly, which can intensify its effects and cause increased jitters or anxiety.
Hormonal Response: Coffee can spike cortisol levels, especially in the morning when levels are already naturally high, which may heighten stress and nervousness.
Blood Sugar Impact: Some evidence suggests drinking coffee without food, especially after poor sleep, can negatively affect blood sugar control.
Mitigation Strategies: Eating a meal, adding milk, choosing dark roasts or cold brew, and hydrating with water first can help minimize negative effects.
Listen to Your Body: If you consistently experience symptoms like anxiety or stomach upset, it is a sign that your body may tolerate coffee better with food or not at all.

The Science Behind Your Morning Cup

While coffee offers benefits like increased alertness and metabolism, its effects on an empty stomach are influenced by several factors, including the speed of caffeine absorption and its interaction with digestive and hormonal systems. When consumed without food, the stimulating effects can be felt more intensely and rapidly, which can be either a welcome boost or a source of discomfort.

Digestive Impact: Acidity and Heartburn

One of the most cited concerns about drinking coffee on an empty stomach is the effect on the digestive system. Coffee is an acidic beverage that also stimulates the production of stomach acid. For individuals with sensitive stomachs or pre-existing conditions like irritable bowel syndrome (IBS) or gastroesophageal reflux disease (GERD), this can lead to uncomfortable symptoms:

Heartburn and Acid Reflux: Coffee relaxes the lower esophageal sphincter, the muscle separating the esophagus from the stomach. This allows stomach acid to more easily enter the esophagus, causing a burning sensation.
Stomach Upset: The combination of increased stomach acid and the absence of food to act as a buffer can irritate the stomach lining, potentially causing pain, bloating, or cramping.
Increased Bowel Motility: Coffee, particularly caffeinated varieties, stimulates contractions in the digestive tract. This can lead to a stronger and quicker urge to use the bathroom, or even loose stools, for some individuals.

Hormonal Fluctuations and the Jitter Effect

Beyond digestion, coffee can influence your body’s hormonal balance. When you wake up, your body's levels of cortisol, the stress hormone, naturally peak to help you feel alert. Drinking coffee soon after waking can cause an additional, and sometimes excessive, spike in cortisol. For some people, this hormonal surge results in heightened feelings of anxiety, nervousness, or the dreaded caffeine jitters. Over time, consistently high cortisol levels might disrupt your sleep-wake cycle and contribute to other health issues. A potential strategy to mitigate this is to wait one to two hours after waking before enjoying your first cup, allowing your body's natural cortisol levels to begin their decline.

The Truth About Blood Sugar

Research has explored the connection between morning coffee and blood sugar. A 2020 study found that drinking strong coffee on an empty stomach, particularly after a night of poor sleep, can negatively affect blood sugar control. Caffeine can temporarily impair insulin sensitivity, potentially leading to a blood sugar spike followed by a crash. For most healthy individuals, this effect is temporary and not a major health concern, but those with diabetes or metabolic issues should be mindful of how their body responds.

Nutrient Absorption: A Timing Game

There is a common misconception that coffee on an empty stomach significantly hinders nutrient absorption. The reality is more nuanced. Coffee contains compounds called tannins that can bind with minerals like iron and calcium, reducing their absorption. However, this effect is most pronounced when coffee is consumed with a meal containing these nutrients. Drinking coffee on an empty stomach has a minimal impact on the absorption of nutrients from a previous meal. If you take mineral supplements, it is best to time your coffee intake and supplement routine appropriately, with a two-hour gap for optimal absorption.

Who Should Be Cautious?

While many people tolerate coffee on an empty stomach without issue, certain individuals are more susceptible to negative side effects. It’s important to pay attention to your body’s signals. You may be in a higher-risk category if you:

Have a history of heartburn, acid reflux, or GERD.
Have a sensitive digestive system or suffer from IBS.
Are prone to anxiety or jitters from caffeine.
Have blood sugar management issues, such as diabetes.
Are pregnant or breastfeeding, due to caffeine's effect on fetal health.

How to Enjoy Coffee with Less Risk

For those who experience adverse effects, there are simple adjustments that can make your coffee routine more stomach-friendly. The key is to find the right balance for your body, rather than giving up coffee entirely.

Mitigation Strategies for Sensitive Stomachs

Pair it with food: Eating a balanced breakfast with your coffee, especially one containing fiber and protein, can help buffer the stomach's acidity and slow caffeine absorption.
Add milk or cream: A splash of low-fat dairy or a plant-based alternative can help neutralize coffee's acidity.
Choose a darker roast: Darker roasts have been shown to be less acidic than their lighter counterparts due to a longer roasting time.
Try cold brew: The cold brewing process results in a smoother, naturally less acidic coffee, making it easier on the stomach for many.
Hydrate first: Start your morning with a glass of water before your coffee to rehydrate and prepare your digestive system.

Comparison: Empty Stomach vs. With Food


Feature	On an Empty Stomach	With Food
Caffeine Absorption	Faster and more intense	Slower and more gradual
Heartburn Risk	Higher for sensitive individuals	Lower due to food buffering acid
Jitters/Anxiety	More pronounced due to rapid absorption	Less severe
Stomach Acid	Stimulates acid without a buffer	Food provides a buffer against acid
Nutrient Absorption	Minimal impact on prior meals, but can affect supplements	Can inhibit absorption of certain minerals like iron

Alternatives to Consider

If modifying your coffee habit isn't enough, or if you prefer to avoid caffeine altogether, several alternatives can provide a morning boost without the side effects.

Herbal Tea: Many herbal teas, like ginger or peppermint, are known for their calming effects on the digestive system.
Matcha Green Tea: Provides a gentler, more sustained energy boost than coffee due to the combination of caffeine and L-theanine, which promotes a state of calm focus.
Warm Lemon Water: A hydrating and gentle start to the day that can support digestion.
Chicory Root Coffee: A caffeine-free alternative that can mimic the flavor of coffee without the acidity.

Conclusion

For most people, drinking coffee on an empty stomach is not harmful, but the key is to listen to your body. For those with no adverse reactions, there is no need to change your routine. However, if you experience discomfort like heartburn, jitters, or digestive upset, simple adjustments can make a significant difference. Eating a balanced meal, opting for a darker roast or cold brew, or simply hydrating first can help you enjoy your morning coffee without the negative side effects. The best approach is always a mindful one, tailoring your habits to your individual needs and sensitivities. For more on how coffee affects the gastrointestinal tract, consider exploring the research summarized in this detailed review on PubMed Central.

Frequently Asked Questions

Yes, for some people, drinking coffee on an empty stomach can cause acid reflux. The caffeine relaxes the lower esophageal sphincter, which allows stomach acid to move up into the esophagus and cause heartburn.

Yes, caffeine in coffee can stimulate an increase in cortisol, the stress hormone. This effect is most pronounced in the morning when cortisol levels naturally peak, potentially leading to increased stress or anxiety for some individuals.

No, drinking coffee does not cause stomach ulcers. Ulcers are typically caused by H. pylori bacteria or overuse of NSAIDs. However, coffee can irritate existing ulcers due to its acid-stimulating properties.

If you are sensitive, waiting one to two hours after waking to drink coffee can be helpful, as it allows your body's natural cortisol levels to begin declining. Having coffee mid-morning can give you a better energy boost without overstimulating your system.

You can mitigate negative effects by drinking coffee with a meal, adding milk or a plant-based creamer, choosing a dark roast or cold brew, and drinking water first thing in the morning.

Yes, cold brew is often recommended for sensitive individuals. The cold brewing process naturally results in a less acidic coffee, which is gentler on the stomach and can help prevent discomfort.

For some people, especially after a night of poor sleep, coffee can temporarily impair insulin sensitivity and affect blood sugar levels. Eating a balanced breakfast with your coffee can help stabilize your blood sugar.

You don't need to avoid coffee, but you should time your intake carefully. Coffee can inhibit the absorption of certain minerals like iron and calcium. Take your mineral supplements at least one to two hours away from your coffee to maximize absorption.