5 Serious Side Effects of Matcha (2025)

While matcha is celebrated for its health benefits and energizing properties, it's not without potential risks. Consuming it in excess can lead to serious side effects ranging from liver toxicity to high blood pressure.

1. Severe Allergic Reaction

A severe allergic reaction is a serious side effect possible with any medication. If you're having a severe allergic reaction to matcha, symptoms may include breathing difficulties, itchiness, and rash.

2. Esophageal Cancer

Hot tea may raise your risk for cancer of the esophagus (tube in the throat that connects to your stomach). Symptoms may include problems with swallowing, coughing, heartburn, and hoarseness.

3. High Blood Pressure

Green tea has raised blood pressure. If your blood pressure is high over long periods, this may increase your risk of other health problems, such as heart attacks and stroke.

4. Liver Problems

In large amounts, green tea (800 mg of EGCG or higher) may also raise your risk of liver problems. If you're experiencing worsening liver function, symptoms may include upper right-sided stomach pain, dark urine, and jaundice (yellowing of your eyes or skin).

5. Decreased Iron Absorption

In high amounts, catechins in tea can decrease iron absorption.

Who Should Avoid Matcha?

A healthcare provider may advise against matcha if any of the following applies to you:

• Severe allergic reaction: Avoid matcha if you have a known allergy to the tea plant or its components (ingredients or parts). If you're unsure, ask a pharmacist or healthcare provider for a complete list of the ingredients.
  
• Pregnancy and breastfeeding: In general, few clinical trials have studied green tea in pregnant or breastfeeding people. But in Italy, the permitted (approved) maximum daily amount is 120 mg of epigallocatechin gallate (EGCG) during pregnancy or while breastfeeding. EGCG is an active substance in matcha at highly concentrated amounts. Since there is little information about the effects and safety of matcha while pregnant or breastfeeding, reach out to a healthcare provider to discuss the benefits and risks.
• Adults over 65: Older adults participated in matcha-related clinical trials, but more extensive research with higher quality, larger, and longer-term studies is still necessary. Some older adults may have a higher likelihood of medication side effects. For this reason, use caution with matcha.
• Children: In general, few clinical trials have studied green tea in children. In one study, an average "exposure" to EGCG ranged between 5 and 87 mg per day for infants, toddlers, or children. Since there is little information about the effects and safety of matcha in children, have a conversation with your child's healthcare provider if you're considering matcha.
• Esophageal cancer: Hot tea might raise your risk of esophageal cancer. A healthcare provider may suggest avoiding hot tea if you already have multiple risk factors for this cancer.
• High blood pressure: Green tea might raise your blood pressure. A healthcare provider may want to monitor you closely if you already have high blood pressure.
• Liver problems: Large amounts of green tea (800 mg of EGCG or higher) may raise your chances of liver problems. If you already have liver problems, a healthcare provider may want to monitor you closely.

How Much Matcha Should I Take?

While there are some studies on matcha in humans, high-quality clinical trials are still necessary. Therefore, no guidelines exist on the appropriate dosage to take matcha for any condition.

In clinical trials, however, some study participants took matcha products at the following amounts for cognition and attention:

• Drink that contains 1.5 g of matcha twice daily
• Four g of matcha tea powder in the form of liquid tea or a tea [food] bar once daily
• Two g of matcha in a capsule form daily
• Three g of matcha in a tea bag daily
• Two g of matcha capsules daily

The specific dose may vary based on the dosage form and the medical condition being addressed. Follow a healthcare provider's recommendations or label instructions when taking matcha.

Interactions

There is limited information about possible medication interactions with matcha. Possible interactions are based on the potential uses or side effects of matcha. Use caution when taking matcha with the following:

• Blood pressure medications: Green tea may raise your blood pressure. So, matcha might work against your blood pressure medications, such as Zestril (lisinopril). For this reason, your healthcare provider may want to monitor and adjust your medications.
• Sleep-inducing medications: Matcha may contain stimulating substances—like caffeine. So, matcha may work against sleep-inducing medications like Ambien (zolpidem).
• Stimulating medications: Matcha may contain stimulating substances, such as caffeine. Matcha may have additive effects and worsen side effects of other stimulating medications, such as attention deficit hyperactivity disorder (ADHD) prescriptions—like Ritalin (methylphenidate).
  

It is essential to carefully read a supplement's ingredients list and nutrition facts panel to know which ingredients and how much of each ingredient is included. Please review this supplement label with your healthcare provider to discuss potential interactions with foods, other supplements, and medications.

Summary

Matcha is a powdered green tea made under stringent rules from the C. sinensis tea plant. It may have potential use for brain health support.

But similar to many medications and natural products, side effects and medication interactions are possible. Further research is necessary. Furthermore, it's essential to properly diagnosis and treat serious medical conditions in a timely manner.

Before taking matcha, consult with a pharmacist or healthcare provider to help you safely achieve your health goals.