Tea has caffeine. A typical brewed cup lands somewhere between 20 and 70mg depending on the tea type — see the table below for specifics. But the number alone does not explain why a cup of Sencha feels different from a cup of coffee with the same amount of caffeine on paper.
Two compounds unique to tea change how your body processes caffeine: L-theanine, an amino acid that promotes calm alertness, and EGCG catechins, which research suggests may slow caffeine absorption in the gut. The result is a gentler, longer-lasting alertness — less spike, less crash. This article explains the mechanism. For caffeine amounts by tea type, the dedicated guides below are the right starting point.
Caffeine tolerance varies widely between individuals. The information here is educational, not a personal intake recommendation. If you have concerns about caffeine and your health, consult your healthcare provider.
Caffeine by tea type — where to look
| Tea type | Caffeine per 100mL (brewed) | Detailed guide |
|---|---|---|
| Sencha | ~20mg | Green Tea Caffeine Guide |
| Gyokuro | ~160mg | Green Tea Caffeine Guide |
| Matcha (per serving, ~2g) | ~64mg per serving (MEXT Standard Tables: Matcha powder 3,200mg/100g × 2g) | Matcha Caffeine Guide |
| Oolong | ~20mg | Oolong Tea Caffeine Guide |
| Hojicha | ~20mg | Hojicha Caffeine Guide |
Source: Japanese Standard Tables of Food Composition (8th revised edition), Ministry of Education, Culture, Sports, Science and Technology
Why tea caffeine feels different from coffee
Tea and coffee both deliver caffeine to the same adenosine receptors in the brain. The difference is what else arrives with it.
L-theanine — found almost exclusively in Camellia sinensis, the tea plant — promotes alpha wave activity in the brain. Alpha waves are associated with a relaxed, attentive state: calm without drowsiness. Caffeine, by contrast, promotes beta wave activity — heightened alertness, sometimes accompanied by tension or jitteriness. Research by Owen et al. (2008, Nutritional Neuroscience) found that the combination of L-theanine and caffeine improved performance on demanding cognitive tasks more than either compound alone.
There is also a second mechanism, less well understood. Some research suggests that EGCG — the primary catechin in green tea — may slow caffeine absorption in the gut, extending the curve rather than sharpening it. Early studies have suggested that EGCG and caffeine together may produce a different absorption profile than caffeine alone, though these findings have not been replicated at scale in humans and should be treated as a plausible hypothesis rather than established science.
The practical effect: coffee tends to deliver peak caffeine quickly — roughly 15 to 45 minutes after drinking, with the sharpest drop at around three to four hours. Tea tends to deliver caffeine more gradually, with a slower peak and a longer, softer tail. How much of this is the theanine effect, how much is the EGCG hypothesis, and how much is simply that most teas are brewed at lower caffeine concentrations than coffee — these are still open questions.
For a deeper look at L-theanine specifically, our theanine guide covers the mechanism, the research, and which teas are richest in it. For the role of catechins, see our catechin guide.
What changes caffeine in your cup
Three factors shape how much caffeine ends up in your cup: what the tea plant produced, and how you brewed it.
| Factor | Effect on caffeine | Example |
|---|---|---|
| Shade cultivation | Increases caffeine | Gyokuro, Matcha — shade stress triggers caffeine production |
| Leaf maturity | Young buds highest | Shincha > Bancha; tips > stems |
| Harvest season | Spring highest | First flush Sencha > summer or autumn harvests |
| Roasting | Minimal reduction | Hojicha slightly lower, not dramatically so |
| Brewing temperature | Higher = more extraction | 90°C extracts significantly more than 60°C |
| Steeping time | Longer = more caffeine | 3 minutes extracts more than 1 minute |
Caffeine is, at its origin, the tea plant's insect defense — a bitter alkaloid that discourages predation. Young buds and leaves under environmental stress produce more of it. Shade cultivation mimics stress and also reduces the light-driven conversion of theanine into catechins, which means shaded teas tend to be high in both caffeine and theanine simultaneously. That is part of why Gyokuro tastes so rich and focused — not just mellow.
Processing matters less than most people assume. Roasting (as in Hojicha) causes a modest reduction. Oxidation (as in oolong and black tea) has a similarly modest effect. The bigger variables are shade, harvest timing, and how you brew. Our covered cultivation article goes into the shading mechanism in detail.
Common questions
Does tea have more caffeine than coffee?
Per gram of dry leaf, tea actually contains comparable — sometimes more — caffeine than coffee beans. But per cup, coffee typically wins: a standard 200mL coffee delivers 80 to 100mg, while a 200mL cup of Sencha delivers around 40mg. The difference is that coffee is brewed at a higher ratio of grounds to water, and at higher temperatures. So the leaf is richer, but the cup is not.
Can you remove caffeine by pouring off the first steep?
Partially. A brief first steep does extract some caffeine — research suggests roughly 10 to 20% of total caffeine leaves in the first 30 seconds. But it also pulls theanine and flavor compounds with it, which undermines both the taste and the very moderation effect you might be trying to preserve. A short, hot first steep is not a reliable decaffeination method. If you want genuinely low caffeine, Hojicha, Bancha, Kukicha, or cold-brewed Sencha are more predictable choices.
Is decaf tea truly caffeine-free?
No. Decaffeinated teas typically retain a small residual amount of caffeine — usually 2 to 5mg per cup, depending on the decaffeination method. For most people this is negligible, but those with high caffeine sensitivity should still be aware of it.
Caffeine in tea is not simply a stimulant to manage — it is one part of a system. The theanine, the catechins, the temperature of the water, the age of the leaf: these interact. Understanding the system makes it easier to find the right tea for the right moment. Whether that is a focused morning bowl of Matcha, an afternoon Sencha, or a quiet Hojicha before bed — it starts with the leaf.
References
- Japanese Standard Tables of Food Composition (2020 — 8th revision), Ministry of Education, Culture, Sports, Science and Technology — caffeine values for Japanese tea infusions and matcha powder
- Owen et al., 2008, Nutritional Neuroscience — combined L-theanine and caffeine on cognitive task performance
- NARO (National Agriculture and Food Research Organization) — Japanese tea cultivation and functional-compound research
- U.S. Food and Drug Administration — daily caffeine intake guidance for healthy adults
If you want to explore further, our green tea ingredients overview covers the full spectrum of compounds in Japanese tea. And if you are building your home collection, you can browse our tea leaves — each variety listed with growing method and harvest details.
The information here is educational and does not constitute medical advice. Caffeine sensitivity varies significantly between individuals. For healthy adults, the U.S. Food and Drug Administration considers up to 400mg of caffeine per day generally safe, but this threshold does not apply to pregnant, nursing, or sensitive individuals. If you have specific health concerns about caffeine intake, please consult your healthcare provider.