Side Effects of Drinking Too Much Matcha
Matcha has so many benefits. It's packed with antioxidants, contains L-theanine for calm focus, and delivers sustained energy without the crash. But drinking too much of it can cause problems.
Most side effects stem from caffeine content and concentrated plant compounds.
Because you consume the whole powdered leaf rather than steeping it, matcha delivers a more concentrated dose of everything good and everything that can be problematic in excess.
One or two cups per day is generally safe.
Beyond that, you might start experiencing some unwanted effects.
Caffeine-Related Anxiety
Matcha contains between 38 to 88 mg of caffeine per cup, based on 2g of matcha powder per cup. While that's less than coffee, it can still add up quickly if you drink multiple cups throughout the day.
Even with L-theanine smoothing out the caffeine experience, caffeine still disrupts sleep if consumed too late. The calming amino acid helps prevent jitters, but it doesn't eliminate caffeine from your system any faster. Avoid matcha after 2-3pm if you struggle with sleep.
Excess matcha intake can cause jitters, anxiety, irritability, high blood pressure, heart palpitations, according to Healthline. Some people are more sensitive to caffeine than others, so if you notice your heart racing or feel unusually anxious after matcha, you might be consuming too much.
Digestive Discomfort
If you're sensitive, the tannins in matcha can cause nausea by irritating the digestive tract. Tannins are plant compounds that give matcha its slightly astringent quality.
The best thing to do is have matcha after food, or have it as a matcha latte since the proteins and carbs in milk can bind with the tannins to reduce the irritation. This simple adjustment makes a big difference for people who experience nausea or stomach upset.
Drinking too much matcha can also cause a green poop. This is common, alarming but totally harmless. It's from chlorophyll in matcha, the same pigment that gives the powder its vibrant green color.
Iron Absorption Concerns
Matcha, rich in inhibitory polyphenols and tannins, can reduce iron absorption per reviews of dietary iron regulators. The same catechins that provide antioxidant benefits can bind to iron in your digestive tract, making it harder for your body to absorb this essential mineral.
There's particular risk for those with existing low iron, pregnant women, vegetarians and vegans. These groups already have a harder time maintaining adequate iron levels, so excessive matcha consumption could worsen the issue.
Although it was specifically around green tea and not matcha, there is a study showing that excessive consumption could contribute to iron deficiency. The case involved someone drinking six cups of green tea daily for years, which eventually led to anemia.
Matcha Quality Matters
When you drink matcha, you consume the entire ground leaf, so contaminants matter more. Unlike steeped tea where you discard the leaves, matcha means ingesting everything in that powder.
Low-quality matcha may contain pesticides or heavy metals. Plants absorb compounds from the soil they grow in, and some regions have higher levels of environmental contaminants. This is one reason why sourcing matters.
Choose high-quality, Japanese matcha from reputable sources. Japan has strict agricultural standards and quality control measures. Ceremonial-grade matcha from established tea-growing regions tends to be the safest option.
Finding Your Balance
These side effects might sound scary, but with moderate consumption you've got nothing to worry about.
We personally always stick to 1-2 cups of 753 Matcha or Kōyō Red Matcha per day, before 2-3pm. This amount and timing give you all the benefits without overdoing the caffeine or tannins.
Ultimately, listen to your body's signals and enjoy your matcha. If you notice jitters, stomach discomfort, or sleep issues, you might need to cut back.
Matcha is wonderful, but like anything good, moderation matters.
