Understanding the 'Steady Buzz': Does Tea Release Caffeine Slowly?

October 10, 2025 •

3 min read

While both coffee and tea contain caffeine, a 2024 review found significant differences in the consumer's experience, prompting many to ask, "Does tea release caffeine slowly?". The answer is yes, tea does offer a gentler, more gradual release of its stimulant, a key factor in how your body responds to your morning brew.

Quick Summary

This article explores the biochemical reasons tea provides a sustained, calm energy boost, contrasting it with coffee's rapid effect. It details the role of compounds like L-theanine and tannins in modulating caffeine absorption, explaining why tea drinkers experience fewer jitters and no sudden crash.

Key Points

Slower Absorption: The caffeine in tea is absorbed more gradually into the bloodstream than coffee's due to its unique chemical makeup.
L-theanine's Calming Effect: The amino acid L-theanine, found in tea, promotes a state of calm, focused alertness that balances caffeine's stimulant effects.
Tannins Bind Caffeine: Astringent compounds called tannins in tea bind to caffeine molecules, slowing their absorption and providing a more even energy boost.
Fewer Jitters and No Crash: The combined effects of L-theanine and slow absorption mean tea is far less likely to cause the jitters or the post-caffeine crash associated with coffee.
Adjustable Caffeine Levels: You can control the caffeine content in your cup by adjusting variables like water temperature, steep time, and leaf size.
Matcha is an Exception: While most teas are lower in caffeine than coffee, matcha is a notable exception due to consuming the whole powdered leaf, which results in a potent dose.

The Science Behind Tea's Slow Caffeine Release

Unlike coffee, where caffeine is absorbed rapidly, the caffeine in tea is assimilated more gradually by the body. This difference in absorption kinetics is primarily due to the presence of other natural compounds in tea leaves, including tannins (polyphenols) and the unique amino acid, L-theanine.

The Role of Tannins and L-theanine

Tannins are bitter, astringent compounds that bind to caffeine molecules in the tea brew. This binding process slows the breakdown and absorption of caffeine in the digestive system, delivering a more even and prolonged energy release. L-theanine, an amino acid found almost exclusively in the Camellia sinensis plant, further modifies the experience. It works synergistically with caffeine, promoting alpha brain wave activity that induces a state of calm, focused alertness without sedation. This combination counteracts the potential jittery or anxious feelings that a rapid caffeine spike from coffee might cause.

The Brewing Effect: Controlling Caffeine Extraction

The amount of caffeine extracted from tea leaves is not fixed; it is highly dependent on brewing parameters. This offers drinkers a degree of control over their caffeine intake.

Water Temperature: Higher water temperatures extract more caffeine. While black tea is typically brewed with boiling water, green and white teas use lower temperatures, resulting in less caffeine extraction. Brewing green tea with water that is too hot can also release more tannins, leading to a bitter flavor.
Steeping Time: The longer the tea leaves steep, the more caffeine is released. A short, quick steep will yield a less caffeinated cup, while a longer infusion will maximize the caffeine content. Multiple infusions of the same leaves will also contain progressively less caffeine.
Tea Leaf Form: The surface area of the tea leaves also plays a role. Tea bags often contain smaller, broken leaf pieces (fannings and dust) that have a larger surface area, allowing for a faster and more complete extraction of caffeine in a shorter time compared to whole loose-leaf teas.

Tea vs. Coffee: A Comparative Look at Caffeine

While both beverages are a source of caffeine, the overall experience they provide to the consumer is markedly different. The following table highlights the key differences.


Feature	Tea (e.g., Black or Green)	Coffee (Brewed)
Average Caffeine Content (8 oz)	20–70 mg (varies by type)	95–120 mg
Absorption Rate	Slower and more gradual	Faster and more immediate
Key Modulating Compound	L-theanine	None
Tannins / Antioxidants	Present, binds with caffeine	Absent
Energy Effect	Calm, sustained, and focused alertness	Rapid spike, potential jitters and crash
Stomach Acidity	Generally lower, gentler on the stomach	Higher, can cause discomfort for some

The Role of Tea Type and Processing

The type of tea also affects caffeine levels. Black tea, which is fully oxidized, generally contains more caffeine per serving than green tea, which is unoxidized. However, powerful exceptions exist. Matcha, a powdered green tea where the entire leaf is consumed, can have very high caffeine content. Herbal teas, or tisanes, are not made from the Camellia sinensis plant and are naturally caffeine-free.

Conclusion: A Balanced Approach to Caffeinated Beverages

For those who are sensitive to caffeine or seek sustained energy without the side effects of a sudden crash, understanding how and why does tea release caffeine slowly is key. The presence of L-theanine and tannins in tea fundamentally alters the physiological response to caffeine, creating a smoother, more balanced experience. By adjusting brewing parameters like water temperature and steep time, you can further tailor the caffeine level to your personal preference. Whether you're looking for a gentle morning lift or a focused afternoon boost, tea offers a nuanced and healthful alternative to coffee.

Disclaimer: The information in this article is for informational purposes only and does not constitute medical advice. For health concerns, consult with a qualified healthcare professional. For further reading on caffeine pharmacology, please visit the National Institutes of Health.

Frequently Asked Questions

The slow release is caused by the presence of tannins and L-theanine. Tannins bind to caffeine, delaying its absorption, while L-theanine interacts with caffeine to provide a calmer, more focused energy.

While both teas offer a slower release than coffee, green tea generally has a lower overall caffeine content and is often brewed at a lower temperature, which results in a gentler effect. Black tea is typically higher in caffeine and steeped hotter, leading to a more pronounced, though still gradual, effect.

Yes, you can. To reduce caffeine, use a shorter steep time, use cooler water (especially for green and white teas), or consider whole-leaf tea rather than tea bags, as whole leaves release caffeine more slowly.

The main reason is the synergistic effect of caffeine and L-theanine. L-theanine promotes relaxation and helps counteract the potential for jitters and anxiety often caused by a rapid caffeine spike.

True teas from the Camellia sinensis plant (black, green, oolong, white) all have a slower release mechanism than coffee due to their chemical composition. Herbal teas, or tisanes, are not from this plant and are naturally caffeine-free.

Decaffeinated tea still contains a very small amount of caffeine (around 5-10 mg per cup). This minimal amount would still be modulated by the tea's compounds, but the overall effect would be negligible.

The benefits include a more sustained and steady increase in energy and focus, without the sudden spike and crash associated with coffee. This can lead to increased productivity and improved mood over a longer period.