For most healthy adults, two to three cups of matcha per day is a reasonable upper limit. Beyond that, you start running into problems with caffeine, and if you go significantly higher, a plant compound called EGCG can stress your liver. The exact ceiling depends on how strong you make your matcha and whether you’re pregnant, taking medications, or sensitive to caffeine.
Caffeine Sets the First Limit
Matcha contains 19 to 44 mg of caffeine per gram of powder. A standard serving uses about 2 grams (roughly one teaspoon), which means a single cup delivers somewhere between 38 and 88 mg of caffeine. That’s a wide range because caffeine levels vary by brand, grade, and growing conditions. Ceremonial-grade matcha tends to sit at the higher end.
The FDA considers 400 mg of caffeine per day safe for most adults. If your matcha lands in the middle of the caffeine range (about 60 mg per cup), you could drink roughly six cups before hitting that ceiling. But most people also get caffeine from other sources: coffee, chocolate, energy drinks, or sodas. Factor those in, and the practical limit for matcha alone drops to three or four cups for many people. You’ll know you’ve had too much caffeine when you feel jittery, anxious, or can’t fall asleep at your normal time. A racing heart, headaches, or an upset stomach are other common signals.
If you’re pregnant, the threshold is lower. The American College of Obstetricians and Gynecologists recommends no more than 200 mg of caffeine per day during pregnancy, which translates to roughly two to three cups of matcha depending on strength, and less if you’re getting caffeine from other foods or drinks.
EGCG and Your Liver
Caffeine isn’t the only compound worth tracking. Matcha is unusually rich in a catechin called EGCG, which is the same antioxidant that gives green tea its health reputation. The difference is that with matcha, you consume the whole leaf rather than steeping and discarding it, so you absorb far more EGCG per cup. Ceremonial matcha contains roughly 50 to 57 mg of EGCG per gram of powder, and culinary grades are close behind.
The European Food Safety Authority reviewed human studies and found that EGCG doses at or above 800 mg per day were associated with early signs of liver damage. Below that threshold, no liver injury was observed, but the agency noted it couldn’t pinpoint a guaranteed safe dose from the available data. At two grams of matcha per serving, a single cup delivers roughly 100 to 115 mg of EGCG. That means you’d need to drink seven or more cups in a day to approach the 800 mg concern zone from matcha alone. However, if you’re also taking green tea extract supplements (which pack concentrated EGCG into capsules), you could reach that level much faster. The risk is highest with supplements, not with drinking matcha as a tea.
Iron Absorption and Blood Pressure
High catechin intake can reduce how much iron your body absorbs from food. This is more relevant if you’re already low in iron or follow a plant-based diet where iron is harder to absorb in the first place. If this applies to you, drinking matcha between meals rather than with food helps minimize the effect, since the catechins won’t be competing with iron for absorption at the same time.
There’s also evidence that green tea can raise blood pressure in some people. This is likely tied to caffeine rather than the catechins, and it tends to be a short-term spike rather than a sustained increase. Still, if you’re monitoring your blood pressure or already on the high side, it’s worth paying attention to how your body responds as you add cups.
Medication Interactions
Matcha can interfere with certain medications in ways that matter. It can amplify the effects of stimulant medications, including those prescribed for ADHD, potentially worsening side effects like a racing heart or restlessness. It can also work against sleep medications, making them less effective.
For people taking cardiovascular drugs, the interaction picture is more nuanced. Research has documented interactions between green tea and the blood thinner warfarin, the cholesterol drug simvastatin, and the blood pressure medication nadolol. The average effects were mild to modest, but in people who drink large amounts of matcha or combine it with concentrated green tea supplements, the risk of reduced drug effectiveness or increased side effects goes up. If you take any of these medications and notice an unexpected change in how you feel, your matcha habit is worth mentioning to your prescriber.
A Practical Daily Range
Putting the numbers together, one to three cups of matcha per day keeps most healthy adults well within safe limits for both caffeine and EGCG. At three cups (about 6 grams of powder), you’re looking at roughly 120 to 260 mg of caffeine and 300 to 340 mg of EGCG, both comfortably below the thresholds linked to problems. Four to five cups is likely still fine for people who tolerate caffeine well and aren’t taking interacting medications, but it leaves less margin.
The people who get into trouble tend to fall into a few categories: those combining matcha with green tea extract supplements, those drinking five or more strong cups daily, and those who don’t realize matcha stacks with their other caffeine sources. If you’re making a concentrated “matcha shot” with 3 to 4 grams of powder instead of the standard 2, each one counts roughly as two servings.
Quality also plays a small role in heavy metal exposure. Tea plants absorb lead from the environment, and since matcha involves consuming the whole leaf, trace amounts end up in your cup. At typical consumption levels (a few cups a day), the amounts are well below safety thresholds. But this is another reason that moderate intake is smarter than pushing the upper limits, especially with lower-quality powders sourced from regions with higher soil contamination.