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< class="article__title title does-green-tea-have-caffeine-decoding-caffeine-content"> Does Green Tea Have Caffeine? Decoding Caffeine Content>
Does Green Tea Have Caffeine? Decoding Caffeine Content
Oct 17, 23
This article has been vetted by the Onnit Advisory Board. Read more about our editorial process.
Author: Sony Sherpa

Does Green Tea Have Caffeine? Decoding Caffeine Content

  • by Sony Sherpa

    Medically reviewed by

    Sony Sherpa

    Dr. Sony Sherpa is a board-certified Clinical Doctor and dedicated advocate for holistic medicine, specializing in functional mushrooms. Her blend of medical expertise and passion for alternative wellness lends authenticity to her role as a contributor for Natures Rise.

  • |
  • 6 min read
Does Green Tea Have Caffeine? Decoding Caffeine Content

We've all had that Monday morning caffeine craving. Most individuals satisfy it by drinking a strong builder's tea or black coffee. However, there has always been uncertainty surrounding the caffeine level of a cup of the green brew.

Green tea is reputed to be high in antioxidants and beneficial to various health conditions. Despite all of the benefits of this popular beverage, many people are still unsure whether or not green tea contains caffeine.

Whether you want more caffeine, are trying to avoid it, or are about to go to bed and would rather not lie wide-eyed and awake all night, let's get to the bottom of what's in the popular tea.

So, does green tea contain caffeine? The simple answer is yes! But there’s more to it.

The Basics of Green Tea

The Basics of Green Tea

Green tea has been renowned as a healthy and refreshing drink since ancient times. The green beverage originated in China, dating back to 2737 B.C. when the Chinese ruler drank water with a dead tea leaf cooked within by accident and found it delicious.

The tea is made from the same plant as black tea, a leafy bush called Camellia Sinensis. However, there is a subtle distinction between the two teas; the fermentation or oxidation process differs depending on whether black or green tea is produced. When preparing green tea, the procedure is gentler, and the leaves are oxidized for a shorter time.

The Truth About Green Tea and Caffeine

The Truth About Green Tea and Caffeine

Is there caffeine in green tea? In short, certainly.

Green tea does contain caffeine, albeit at lower levels than coffee. Furthermore, not all green teas are manufactured and distributed identically; subtle variances are worth noting. Specific factors can influence the caffeine level of various varieties of green tea.

For instance, the season of harvest of tea leaves may influence caffeine levels. Earlier harvests of the same plant may have a higher caffeine concentration. This is because the longer the tea leaves are oxidized, the less caffeine they contain. Polyphenols in tea are produced in higher quantities during the time between harvests. These polyphenols can bind to caffeine, making it less available for us to absorb when we drink tea.

Additionally, the water temperature used to boil your tea and the brewing method might affect caffeine levels. Cold-brewed tea contains less caffeine than hot-brewed tea. Brewing time can also be a factor.

Hotter water extracts more caffeine from the leaves. Longer steeping times will result in more caffeine. However, if you use boiling water and soak it for too long, green tea can quickly become bitter. Green tea tastes best when steeped for 1-3 minutes in water between 150 and 195 degrees Fahrenheit. Caffeine levels will be mild as a result of this. Brew 30 seconds in water at 150 degrees F for a less caffeinated cup.

How Much Caffeine In Green Tea?

According to the Food and Drug Administration, an 8-ounce cup of green tea has 30 to 50 mg of caffeine. An 8-ounce cup  (or 236.588 ml) of black tea contains 45-90 milligrams of caffeine, while the same amount of coffee contains 80-100 milligrams of caffeine.

Understanding Caffeine in Green Tea

Understanding Caffeine in Green Tea

Caffeine(1) is a naturally occurring substance found in the beans, leaves, and fruits of over 60 plants, including the leaves of tea plants. It is a central nervous system stimulant used to increase alertness and fight weariness worldwide. It inhibits(2) the effects of a neurotransmitter, adenosine, that accumulates over the day and causes fatigue.

Caffeine use has also been related to various health benefits, such as improved brain function, increased metabolism, enhanced mood, and improved athletic performance.

Some people, however, may be more sensitive to caffeine's effects(3) than others. People who take too much coffee may also develop restlessness, sleeplessness, or an erratic heartbeat.

The Benefits of Caffeine in Green Tea

The Benefits of Caffeine in Green Tea

While green tea provides a little caffeine boost, it also provides a smoother and more consistent source of stimulation, which could help attention. This mixture can also have a calming impact on the brain, making it excellent for relaxing and unwinding.

Green tea also contains L-theanine, an amino acid that has been proven to function in combination with caffeine. As a result, despite the lower caffeine level of green tea(4), you receive a more subtle but different kind of buzz than with coffee.

The combination of L-theanine and caffeine, for instance, has been proven to(5) boost both alertness and focus, making green tea a better drink than coffee if you're doing tasks that need a lot of concentration.

FAQs About Does Green Tea Have Caffeine?

Does Green Tea Keep You Awake?

Drinking green tea during the day will help you sleep better at night.  However, the caffeine in green tea can still keep you awake, so stop drinking it at least two hours before going to bed.

Is Green Tea A Good Alternative To Coffee For Reducing Caffeine Intake?

Green tea contains less caffeine than coffee, while the latter contains more caffeine. One 8-ounce cup of green tea typically contains 30 to 50 milligrams of caffeine, whereas one 8-ounce cup typically contains 80 to 100 milligrams of caffeine.

Does Green Tea Have Side Effects?

Green tea's side effects include tremors, anxiety, difficulty sleeping and irritability. This is more likely if you are caffeine-sensitive or consume significant amounts of caffeine.

Key Takeaways

Does green tea have caffeine? It certainly does. However, it contains less caffeine than black tea and far less caffeine than coffee. While green tea contains caffeine, it is milder than a higher-caffeine beverage, which may cause an energy drop later.

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  1. Caffeine (1, 3, 7-trimethylxanthine) in foods: a comprehensive review on consumption, functionality, safety, and regulatory matters, (1) 
  2. The role and regulation of adenosine in the central nervous system, (2) 
  3. Caffeinated energy drinks--a growing problem, (3)
  4. Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: a systematic review and meta-analysis, (4) 
  5. The combined effects of L-theanine and caffeine on cognitive performance and mood, (5)

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