Why do I feel weird after drinking yerba mate?

October 9, 2025 •

4 min read

Over 90% of adults consume caffeine daily, yet the stimulating effects can vary significantly depending on the source. If you've asked, "Why do I feel weird after drinking yerba mate?" it's because this popular South American brew has a distinct profile of stimulants and other compounds that affect the body differently than coffee or standard tea.

Quick Summary

Yerba mate can cause feelings of weirdness, anxiety, or jitteriness due to its unique combination of caffeine, theobromine, and theophylline, which affect the central nervous system differently than coffee. Other factors include your caffeine sensitivity, the preparation method, and whether you consume it on an empty stomach, which can lead to rapid absorption and gastrointestinal discomfort.

Key Points

Stimulant Synergy: Yerba mate contains a blend of caffeine, theobromine, and theophylline, which together create a smoother but different stimulating effect than the caffeine alone in coffee.
Caffeine Sensitivity Matters: Your individual tolerance to caffeine is a major factor, and those who are sensitive may experience anxiety, jitters, or restlessness from yerba mate, especially when first starting.
Don't Drink on an Empty Stomach: Consuming yerba mate without food can cause rapid caffeine absorption and lead to digestive issues like nausea or an upset stomach.
Beware of Overconsumption: Traditional methods of drinking from a gourd can lead to a much higher caffeine intake than a single cup. Moderation is key to avoiding negative side effects.
Watch the Water Temperature: Brewing with water that is too hot can increase the extraction of bitter tannins, potentially leading to a harsher flavor and stomach irritation.
Theobromine's Mellowing Effect: The presence of theobromine in yerba mate helps relax smooth muscles, which can counteract some of the jittery effects of caffeine, resulting in a more balanced, 'focused' energy.

The Yerba Mate Stimulant Trifecta

Unlike coffee, which delivers a potent and sometimes jarring dose of caffeine, yerba mate contains a blend of three methylxanthine stimulants: caffeine, theobromine, and theophylline. This combination is the primary reason for the unique and sometimes 'weird' feeling people experience. Caffeine provides alertness and energy by blocking adenosine receptors in the brain. Theobromine, also found in chocolate, has a milder, longer-lasting stimulating effect and acts as a smooth muscle relaxant, particularly on the cardiovascular system, which can help counterbalance the jitteriness of caffeine. Finally, theophylline also has a stimulating effect but is more potent in relaxing the smooth muscles of the airways. Together, these compounds create a more balanced and sustained energy boost, but their combined effect can be unusual for those accustomed to the sharp spike and crash of coffee.

How Caffeine Sensitivity Plays a Role

Individual sensitivity to caffeine is a significant factor in how you react to yerba mate. Genetics, body weight, and overall health all influence how quickly your body metabolizes caffeine. For someone with high caffeine sensitivity, even the moderate amount in yerba mate can trigger anxiety, restlessness, and an increased heart rate. If you are new to yerba mate, it is crucial to start with a smaller quantity to gauge your body's reaction. The traditional method of drinking yerba mate—refilling a gourd multiple times—can lead to a much higher total caffeine intake than anticipated, potentially overwhelming your system.

Potential Side Effects and How to Avoid Them

Experiencing a "weird" feeling after drinking yerba mate can manifest as several specific side effects. The good news is that these can often be managed or prevented with simple adjustments to your consumption habits.

Anxiety and Jitters: While yerba mate's blend of stimulants is generally smoother than coffee, excessive consumption can still lead to caffeine overload, causing nervousness and a racing heart.
Upset Stomach: The caffeine and other compounds can stimulate the digestive system, leading to nausea, stomach upset, or diarrhea, especially when consumed on an empty stomach. Saponins, which give yerba mate its foamy head, can also irritate a sensitive digestive tract.
Headaches: For some, the powerful diuretic effect or vasoconstrictive properties of caffeine can trigger headaches, especially if not consumed with sufficient water.
Insomnia: The stimulating effects, while less intense than coffee, can still interfere with sleep patterns if consumed too late in the day.

To mitigate these issues, consider the following list of practices:

Start Small: Begin with a single, small serving and gradually increase your intake as your body adjusts.
Eat First: Never drink yerba mate on an empty stomach, as this accelerates caffeine absorption and can increase digestive issues. Pair it with a meal rich in fats and protein to slow absorption.
Watch the Temperature: Very hot water can increase the extraction of bitter tannins and potentially lead to esophageal irritation over time. Brew with water between 70–80°C (158–176°F).
Stay Hydrated: The diuretic effect of mate means you should drink extra water throughout the day to avoid dehydration-related side effects.

Yerba Mate vs. Coffee: A Comparative Analysis

To further understand the unique effects of yerba mate, a comparison with the more familiar effects of coffee can be useful. The table below outlines some key differences in their stimulant profiles and associated side effects.


Feature	Yerba Mate	Coffee
Stimulants	Caffeine, Theobromine, Theophylline	Primarily Caffeine
Energy Curve	Smooth, sustained energy with less crash.	Rapid spike followed by a potential crash.
Jitters & Anxiety	Less common due to theobromine.	Common in sensitive individuals due to high caffeine spike.
Digestive Impact	Often gentler on the stomach and less acidic.	Can cause heartburn or acid reflux due to higher acidity.
Tannin Content	Moderate, can be controlled by water temperature.	Negligible in comparison.

Conclusion: Finding Your Mate Rhythm

The "weird" feeling associated with drinking yerba mate is a complex interplay of its unique stimulant profile, your individual physiology, and your consumption habits. It's not a mystery but a matter of understanding the brew. By being mindful of your caffeine tolerance, eating beforehand, and moderating your intake, you can move past the initial odd sensations and appreciate the smooth, sustained energy and mental clarity yerba mate is celebrated for. As with any potent botanical, listening to your body is the most important part of the ritual. If the unsettling feelings persist, consulting a healthcare professional is always a wise course of action.

References

[1] The Impact of Caffeine Consumption on Mental Health: A Comprehensive Review of the Literature - PubMed Central. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8622869/ [2] Yerba Mate Tea (Ilex paraguariensis): A Comprehensive Review on Chemistry, Health Implications, and Technological Considerations - Journal of Food Science. Available at: https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1750-3841.2007.00535.x [3] Yerba Mate - LiverTox - NCBI Bookshelf. Available at: https://www.ncbi.nlm.nih.gov/books/NBK610218/

Frequently Asked Questions

Yes, yerba mate contains caffeine, though typically slightly less per cup than coffee. However, the total caffeine consumed can be higher when following the traditional method of repeatedly refilling the gourd.

Yes, if you are sensitive to stimulants or consume it in large quantities, the caffeine in yerba mate can cause or exacerbate feelings of anxiety, nervousness, and a racing heart.

Yerba mate can cause gastrointestinal discomfort due to its caffeine content, especially when consumed on an empty stomach. The presence of saponins can also irritate sensitive digestive systems.

While it is possible to have an allergy, the weird feeling is most often a result of your body's physiological response to the specific combination of stimulants and other compounds in the brew, rather than an allergic reaction.

To minimize side effects, start with a small amount, avoid drinking on an empty stomach, use cooler water for brewing, and ensure you stay hydrated.

Yerba mate is often cited as providing a smoother, more balanced energy boost with fewer jitters than coffee, and is rich in antioxidants. However, the 'better' option depends on personal preference and how your body reacts.

Many people report that yerba mate provides a more sustained energy release without the crash often associated with coffee. The combination of caffeine, theobromine, and theophylline contributes to this more gradual effect.

This common experience is likely due to the synergistic effect of yerba mate's compounds. The caffeine provides alertness, while theobromine helps relax smooth muscles, resulting in a state of calm focus without the intensity of a typical caffeine rush.