Matcha latte in a glass with a Lucarise matcha box, sachet, bamboo whisk and dates on a wooden table

Matcha Side Effects: What the Research Says and Who Should Be Careful

Quick answer: For most healthy adults, matcha drunk as a beverage in normal amounts has no known safety concerns. The possible side effects come mainly from too much caffeine, lower iron absorption in people with low iron stores, interactions with some medicines, stomach upset on an empty stomach, and the sugar in many café matcha drinks. The liver problems linked to green tea come mostly from concentrated extract supplements, not from the drink.

Matcha has become one of the most popular drinks in Saudi Arabia and the Gulf, and with that come many questions about its side effects. This article looks at what the research actually says: which matcha side effects are real, who should be careful, and how much is reasonable. It is general information, not medical advice. If you have a health condition or take regular medicines, ask your doctor.

Health

Matcha side effects

What the research says, who should be careful, and how to enjoy matcha safely.

Is Matcha Bad for You?

Matcha is green tea leaf ground into powder, so you drink the whole leaf. The US National Center for Complementary and Integrative Health (NCCIH) says that no safety concerns have been reported for green tea consumed as a beverage by adults[1]. Most of the possible side effects of matcha are about the amount, the person and what is added to the cup.

1. Too Much Caffeine

Matcha contains caffeine, and the amount varies a lot between products. One 2024 study measured about 2.2 mg of caffeine per gram in the matcha it tested, and noted that an earlier study had found 14.4 to 34.1 mg per gram[4]. So a 2 g cup could have anything from a few milligrams to nearly 70 mg.

Too much caffeine can cause trouble sleeping, nervousness or a fast heartbeat. The European Food Safety Authority considers up to 400 mg of caffeine a day from all sources safe for healthy adults, and up to 200 mg a day during pregnancy and breastfeeding[3]. Compare drinks in our caffeine chart.

2. Iron Absorption

Tea contains polyphenols that can reduce the absorption of iron from plant foods. A review of studies found no effect of tea on iron status in people with adequate iron stores, but an inverse link in groups at higher risk of iron deficiency, such as children and premenopausal women[5]. If you have iron deficiency or take iron tablets, ask your doctor when to drink tea in relation to meals and tablets.

3. The Liver: Supplements, Not the Drink

The European Food Safety Authority concluded that catechins from green tea infusions and similar drinks are generally safe, while doses of 800 mg or more of EGCG a day from supplements were linked to raised liver enzymes[2]. NCCIH also notes that liver problems have been reported mainly with green tea extracts in pills or capsules[1]. One or two cups of matcha are far below these supplement doses.

4. Interactions with Medicines

According to NCCIH, large amounts of green tea may lower blood levels of nadolol, a heart medicine, and green tea extract may lower levels of atorvastatin, a cholesterol medicine. An interaction with raloxifene has also been studied[1]. If you take regular medicines, ask your doctor or pharmacist about matcha and green tea.

5. Stomach Upset and Sleep

Some people feel stomach discomfort when they drink strong matcha on an empty stomach. Making it with milk or drinking it after a small meal usually helps. Because of the caffeine, avoid matcha in the hours before bedtime if it affects your sleep.

Hot matcha latte in a glass mug with a jug of milk, matcha powder and a bamboo whisk

6. Hidden Sugar in Café Matcha

Often the biggest problem with a café matcha latte is not the matcha but the syrup. The World Health Organization recommends keeping free sugars below 10% of daily energy, ideally below about 25 g a day for an adult[6]. Ask for no syrup, or make a sugar-free matcha latte at home.

Who Should Be Careful with Matcha?

  • Pregnant and breastfeeding women: keep total caffeine moderate and ask your doctor[1][3].
  • Children: matcha contains caffeine, so it is not a children’s drink.
  • People with iron deficiency or who take iron tablets[5].
  • People sensitive to caffeine, or with sleep problems or anxiety.
  • People who take regular medicines such as nadolol, atorvastatin or raloxifene[1].
  • People with liver disease, especially before using any green tea supplement.

How Much Matcha per Day?

There is no single number for everyone. It depends on how much caffeine your matcha has and how much caffeine you get from coffee, tea and other drinks. For most healthy adults, one or two cups of matcha a day fit comfortably within 400 mg of caffeine from all sources[3]. If you want to be precise, use pre-measured sachets so you know the dose in each cup.

How to Enjoy Matcha with Fewer Side Effects

  1. Drink it with milk or after a small meal if your stomach is sensitive.
  2. Keep it to the morning and early afternoon.
  3. Count all your caffeine, not only matcha.
  4. Skip the syrup or choose a version with no added sugar.
  5. Buy matcha from a trusted source with a clear origin, because you drink the whole leaf.
  6. Choose the drink, not concentrated green tea extract pills, unless your doctor advises otherwise.
Lucarise matcha

Know exactly how much matcha is in your cup

Lucarise Ceremonial Matcha comes in 1 g sachets, so you always know your dose. Lucarise Classic Matcha Latte has no added sugar in the mix and comes with a separate stevia sachet, so you choose the sweetness.

Ceremonial matcha powderClassic matcha latteCardamom matcha powder

Matcha Side Effects: Quick Questions

Is it OK to drink matcha every day?

For most healthy adults, yes, in moderate amounts. Keep an eye on your total caffeine from all drinks, and ask your doctor if you are pregnant, have iron deficiency or take regular medicines.

Does matcha affect iron?

Tea can reduce the absorption of iron from plant foods. Research found no effect in people with adequate iron stores, but people with low iron should ask their doctor about timing.

Is matcha bad for the liver?

Liver problems linked to green tea come mainly from concentrated extract supplements with high doses of EGCG, not from drinking matcha in normal amounts.

Can pregnant women drink matcha?

Matcha contains caffeine. EFSA advises up to 200 mg of caffeine a day from all sources during pregnancy. Ask your doctor for personal advice.

Why does matcha upset my stomach?

Strong matcha on an empty stomach can bother some people. Try it with milk or after eating.

Sources

  1. National Center for Complementary and Integrative Health (NCCIH). Green tea: usefulness and safety. www.nccih.nih.gov
  2. EFSA Panel on Food Additives and Nutrient Sources. Scientific opinion on the safety of green tea catechins. EFSA Journal, 2018. www.efsa.europa.eu
  3. EUFIC. EFSA opinion on the safety of caffeine (2015). eufic.org
  4. Kika J. et al. Matcha green tea: chemical composition, phenolic acids, caffeine and fatty acid profile. Foods, 2024. pmc.ncbi.nlm.nih.gov
  5. Temme EHM, Van Hoydonck PGA. Tea consumption and iron status. European Journal of Clinical Nutrition, 2002. www.nature.com
  6. World Health Organization. Guideline: sugars intake for adults and children, 2015. www.who.int

Keep reading

Matcha benefitsWhat is matchaCaffeine chartMatcha vs coffeeSugar-free matcha latteHow to make matcha latteMatcha tools
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