Tea is one of the most universally enjoyed beverages on earth. It’s present in all cultures and countries, from China to Uganda, and even Argentina. The drink can be made with your choice of leaves, flowers, roots, needles from shrubs, and even stems. Depending on how the plants are grown (in shade or full sun), how they are dried, and how they are processed, the same plant can produce a wide variety of teas. (Updated Feb 28, 2024)
For some, tea is a sacred tradition, for others it’s a medicine, and for many of us, it’s simply a way to unwind and enjoy ourselves. Despite its calming properties, many people wonder: does green tea have caffeine? In short, the answer is yes, but it’s not as straightforward as you may think.
What Is Caffeine?
Caffeine is a stimulant that naturally occurs in tea, coffee, and cocoa. Plants create the compound through nitrogen metabolism and it acts as a natural pesticide.
Caffeine is technically classified as a psychoactive drug, due to its stimulating effects on the nervous system. Sodas, energy drinks, and medications, such as cough medicine and pain remedies can all contain the substance (1).
According to the Canadian Center for Addiction and Mental Health, “In North America, more than 80 percent of adults regularly consume caffeine.” Caffeine has some positive effects, as it can improve alertness, concentration, energy, clear-headedness, and feelings of sociability (2).
Unfortunately, caffeine can cause physical dependence. If you’re used to taking caffeine daily, you may experience fatigue, headache, anxiety, irritability, depressed mood, and difficulty concentrating if you don’t get your fix (3).
Does Green Tea Have Caffeine?
Yes. Green tea contains some caffeine. In fact, black tea, green tea (including matcha), white tea, yellow tea, oolong, mate, and pu’erh all contain caffeine. These varieties (except mate) all come from the Camellia sinensis plant: they just have different transformation processes.
Green tea can be enjoyed at night if the leaves were plucked that very morning. It’s one of the least processed teas, depending on the variety. Each variety has its particularities, from the country of origin to the drying process. Japanese matcha, for example, is shade-grown to boost the production of chlorophyll and beneficial nutrients. Popular green teas include genmaicha, sencha, jasmine, dragonwell, and gyokuro yamashiro.
Black tea is fully oxidized and has a more robust and complex flavor. It also contains more caffeine than green tea. Popular black teas include Assam, English breakfast, Irish breakfast, orange pekoe, Nepal black, and lapsang souchong, a smoked tea.
White Tea is even less processed than green tea and has the lowest caffeine content of all the teas on this list. To make it, tea leaves are picked when young tea buds are tightly enclosed in new leaves, giving it a slightly silky flavor. White teas include bai hao yin zhen, white peony, shou mei, and gong mei.
Oolong is semi-oxidized, so it’s between green and black tea in terms of flavor and caffeine content. Popular oolongs include milk oolong, oolong supreme, tie kwan yin, and ruby oolong.
Pu’erh is an aged and fermented tea with a slightly “fishy” smell. It’s close to black tea in terms of caffeine content.
Yellow tea is very rare, and therefore, very prized. It’s made from the spring buds of Camellia sinensis that are pan-fried and painstakingly oxidized over the course of three days. Tea makers then dry them slowly dried over charcoal. It’s between white tea and green tea in terms of caffeine, flavor, and color.
Herbal teas, which are made from herbs, roots, fruits, and flowers, do not contain caffeine. Roobois, a “red tea”, is actually caffeine-free too. It has needle-like leaves and comes from a South African bush.
How Much Caffeine is in Green Tea?
Put simply, green tea contains roughly the same amount of caffeine as 12oz of cola. Black tea contains between 14-70mg per cup while green tea contains between 24-45mg, depending on the variety and quality of the tea (6).
To put it in perspective, brewed coffee contains between 95-200mg per cup, espressos hover between 45-75mg, while lattes can be between 63-175mg.
But caffeine from tea does not act the same ways as coffee-based caffeine. That’s because tea contains L-Theanine, an amino acid that has a calming effect on the brain. It actually offsets the stimulatory effects of caffeine to supply a steady stream of energy instead of a big rush (7).
What Else is in Green Tea?
Green tea contains 450 known organic compounds, so it’s no surprise that it’s a superfood. Most notably, tea contains EGCG, or epigallocatechin gallate. It’s a powerful compound that can fight cancer, prevent cell damage, prevent heart disease, lower cholesterol, prevent stroke, boost weight loss, improve type 2 diabetes, improve memory, control inflammatory skin disease and fight off Alzheimer’s and dementia (8,9,10,).
Here are some of the other most powerful compounds green tea contains (11):