The Zest Tea Guide to Green Tea Energy

The Zest Tea Guide to Green Tea Energy

The Zest Tea Guide to Green Tea Energy

From losing belly fat to reducing fatigue and clearing your skin - green tea has been presented as a miracle cure for almost everything. But is green tea really capable of all these feats? Are green tea energy levels higher or different to other tea types? How does this impact your daily energy levels and mood?

Our guide to green tea energy will explain it all. Take a look at the caffeine content, health benefits and research into natural green tea here. If you're looking for green tea with a bit of a kick, don't be afraid to check out Zest's high caffeine tea too.

  HIGH CAFFEINE TEAS  We get it - you can't function before caffeine hits your bloodstream. Good thing Zest has more caffeine than coffee, plus your stomach won't hate you for drinking it.   ENERGY: 3X the amount of caffeine found in regular teas FOCUS: L-Theanine for all-day, steady alertness HEALTH: No surgar and made with completely natural ingredients  SEE PRODUCT PAGE

An In-Depth Look at Green Tea

Green tea is just one type of tea that can be made and consumed. Here's how green tea is processed and how this differs from other tea types, including black tea.


Growing and Processing Green Tea

Green tea is made from the leaves of the Camellia sinensis tea plant. This plant is native to China but is grown in many countries around the world. Some of the most iconic green teas are grown in Japan, China, India, and Taiwan.

There are many varieties and ‘cultivars’ of the Camellia sinensis tea plant, but there is no specific "green tea" cultivar. The factor that determines whether a tea is green, black, oolong, white, or another type, depends on the processing. That being said, there are some tea cultivars that produce leaves that are better as green tea than any other!

To turn the tea leaves and buds into green tea, they are picked by hand or machine and quickly fixed to prevent oxidation and fermentation. Usually, enzymes within the tea leaves will start to oxidize the tea leaves once they've been picked. This turns the leaves from green to brown and alters the flavor too. By fixing the tea leaves - quickly exposing them to a high heat - the enzyme activity is prevented and the leaves retain their green, fresh qualities. Most green teas are pan-fired or steamed to achieve this.

Finally, the tea leaves or buds are shaped and dried one final time before they can be processed into teabags and loose leaf tea.

green tea fields

Green Tea Caffeine and Nutrients

As green tea can be made from numerous different tea plant cultivars, the exact levels of different nutrients and compounds vary from one cup to the next. However, in general, here are some of the chemical compounds you can expect to find in every dose of green tea:

  • Xanthine derivatives - these sound a little chemical-like, but they're completely natural compounds formed by the tea plant. These compounds are stimulants and are the key to green tea energy. The most well known of these is caffeine. There is roughly 28mg of caffeine in an 8oz cup of green tea.
  • Polyphenols, catechins, and antioxidants - polyphenols are micronutrients formed by a variety of plants and tea is a great source of them. One particular group of polyphenols found in tea are known as catechins or flavanols. Catechins give the tea its tannic, astringent flavor. They also have antioxidant properties, meaning they prevent oxidation which has numerous health benefits that we'll explore further. Tea has some unique catechins that you won't find produced by any other plant. Furthermore, these catechins change when they're oxidized into catechin dimers - this is what gives black tea that reddish hue and different antioxidant health benefits to green tea (which has very few catechin dimers).
  • Epigallocatechin 3-gallate (EGCG) - one of the most studied antioxidants in green tea is EGCG. Up to 75% of the total flavonoid content of green tea can be made up of this one catechin. The properties of EGCG are linked to numerous health benefits.
  • Amino acids - green tea contains several amino acids but the most well-known (and important) amino acid is L-Theanine. L-Theanine produces a calming effect and interacts with the caffeine content. Learn more about this below. Up to 60% of all the amino acids in green tea are theanine, and you can only find theanine produced naturally in the tea plant. Sorry, coffee lovers.

Green tea is also a good source of vitamins. Some vitamins, such as vitamin C, are extremely heat sensitive or will degrade when fermented and oxidized. This is why unoxidized green tea is generally considered a better source of vitamins and nutrients than oxidized black tea.

In green tea you'll find small amounts of vitamin B2, vitamin C, folic acid, β-carotene (a precursor to vitamin A), vitamin E, and saponins.


A Quick Note About Matcha

Matcha is often a popular choice among recovered (or recovering) energy drink and coffee addicts. It provides up to 70mg of caffeine per cup which is a much larger energy boost than you'll get from drinking green tea. This is due to how the tea plant is grown for matcha, as well as how the green tea leaves are processed and finally brewed.

First, matcha is made from tea plant varieties that are shade-grown. By growing the tea plant in the shade rather than in direct sunlight, the leaves have a higher caffeine and L-Theanine content. While this boosts the stimulating, energizing compounds in green tea, it also suppresses the generation of catechins.

To make matcha, you whisk the powdered tea leaves into water (or milk, if you're making a matcha latte). While the nutrients in a cup of green tea partly rely on how long you have brewed the leaves, with matcha tea you are consuming 100% of the tea leaves and thus 100% of the nutrients available.

If you want to learn more about this, read our Guide to Understanding Matcha Tea Caffeine.

matcha on a teaspoon

How Caffeine Provides Energy

When we talk about how tea can provide us with energy, we are nearly always referring to the caffeine content. We measure the caffeine content in milligrams and it's important to know that most of these figures are only estimates. There are several variables that determine how much caffeine is in a cup of tea. First, there's the level of caffeine in the tea leaves (which will vary between types and varieties), then there's your brewing method, water temperature, and steeping time.

At Zest Tea, we are a little bit obsessed with caffeine, so we've measured exactly how much caffeine ends up in a cup of our black tea or green tea energy blends.

Once you've sipped your cup of coffee or tea, here's how the caffeine works:

  • Caffeine enters your bloodstream and takes roughly 45 minutes to kick in,
  • Caffeine molecules pass through the blood brain barrier and bind to adenosine receptors in your brain,
  • Adenosine usually binds to these receptors to create sleepy, sluggish feelings... but the caffeine prevents this,
  • As a result, you feel awake, refreshed and energized,
  • When the caffeine wears off (roughly 5 hours later) the adenosine can begin to bind with receptors again, leaving you sleepy, sluggish, and craving another cuppa.


How L-Theanine Interacts with Caffeine

Whether you get your caffeine from tea, coffee, or an energy drink, it works in the same way. Binding to adenosine receptors is how it provides that wide-awake feeling... but too much caffeine can also cause those jittery, unfocused vibes. It's hard to harness all the energy you feel after drinking a high caffeine beverage.

This is where the amino acid L-Theanine steps in.

Just like caffeine, L-Theanine enters your bloodstream and passes through the blood-brain barrier. Not only does L-Theanine slow the onset of caffeine, so you get a gradual and natural boost of energy, but it provides extra mental alertness.

Studies have found that L-Theanine can:

  • Reduce psychological stress responses and keep your heart rate calm (caffeine in high quantities can increase your heart rate and blood pressure otherwise).
  • Reduce stress when multitasking, which is great news for busy workday afternoons.
  • Significantly increase mental alertness and creativity, to keep you focused and smashing goals at record speed.
  • Help manage stress and anxiety disorders, promoting a calm state of mind.


Beat That Mid-Afternoon Crash

With L-Theanine and caffeine working together, you can really harness the energy that green tea provides. Boost your creativity and productivity by focusing your newfound energy on the task at hand.

Compared to coffee and caffeinated energy drinks, the effects of green tea energy are smoother, calmer, and associated with productivity rather than uncontrollable jitters and speed-talking.

The best tea for energy therefore has high levels of both caffeine and L-Theanine to balance and control your energy boost. The problem is, most green tea types contain quite low amounts of caffeine. So, let's compare green tea energy to the energy you'll get from other tea types, including Zest Tea's high caffeine green tea blends.

green tea in glass mugs

Green Tea Energy vs Other Teas

It's not just the Camellia sinensis cultivars that provide a source of caffeine. Here's how green tea stacks up against some of the most highly caffeinated tea types available.


Black Tea

Black tea is made in a similar process to green tea, but with added steps to oxidize the tea leaves. By oxidizing the leaves, you allow the enzymes to darken the leaves. This creates a richer, bolder and often malty tannic flavor. It also changes the catechins and the health benefits related to them.

Black tea contains 47mg of caffeine per cup on average. This is more than green tea, but still way less than a cup of coffee. As for the all-important amino acid, one study has found that black tea contains more L-Theanine than green tea.

However, they admit that L-Theanine levels depend greatly on how you brew your tea. The study also doesn't take into account the differences in L-Theanine in shade-grown leaves.


Yerba Mate

Yerba mate is made from the Ilex paraguariensis shrub rather than Camellia sinensis. You might have heard that yerba mate contains more caffeine than traditional tea, but it really depends on how you prepare it.

Traditional methods involve using tablespoons of the dried yerba mate leaf, brewed in a gourd. You can also find yerba mate in teabag format, which usually holds around 2g of leaf. Yerba mate contains between 180mg and 30mg of caffeine per cup as a result.

Yerba mate does not contain any L-Theanine but it does provide a range of healthy polyphenols with antioxidant properties, including chlorogenic acids. Catechins are not present in yerba mate.


Herbal Teas

Herbal tea often refers to any tea (or infusion) that's not made from traditional tea leaf material. This includes fruit teas as well as infusions made from leaves, flowers, roots, stems and other plant matter.

With some exceptions, like yerba mate, most herbal teas are completely caffeine-free and do not contain tea amino acids either. The big exception is our Sleep Tea Blend. We combine chamomile and lavender (known sleep-inducing ingredients) with added melatonin and L-Theanine extracted from tea, for a little extra calm before you go to bed.

At Zest Tea, we've written a few interesting guides to herbal teas to help you understand their health benefits better:


Zest Green Tea

A standard cup of green tea contains just 28mg of caffeine per cup. This is a little less than black tea and a lot less than a cup of coffee. But at Zest Tea, our green tea blends provide up to 135mg of caffeine instead.

First, we select the best Young Hyson Chinese green tea to create the base of our teas. Then we add non-GMO ingredients and natural flavours to tantalize your taste buds. Finally, our unique method of adding additional tea extract enables us to naturally boost the levels of caffeine while retaining the L-Theanine and polyphenol content that makes tea so great.

Check out our loose leaf and pyramid teabags.


Zest Black Tea

Besides green tea, we also have some high caffeine black teas that you might enjoy. If you can't wake up without your strong cup of coffee, a black tea might be more to your tastes. Besides providing L-Theanine and caffeine, black tea is also great with a splash of milk and comes with it's own range of health benefits.

To compare green tea energy levels with other tea types, read What Type of Tea Has The Most Caffeine?

zest black tea picnic

Green Tea Extract

Too much of a good thing can quickly become a bad thing. Usually, drinking one or even five cups of green tea in a day is completely safe and enables you to enjoy the energy and health benefits. But green tea extract is a whole other story.

Green tea extract contains highly concentrated doses of ECGC, L-Theanine and possibly caffeine as well (depending on the brand). There's evidence that consuming these compounds in extremely high doses could cause acute liver toxicity.

The best way to enjoy these healthy micronutrients in safe doses is to drink tea the old-fashioned way. Even our Zest Tea blends, with 135mg of caffeine per cup, contain far less than the 400mg recommended daily limit set by the FDA.


Green Tea Energy vs Coffee Energy

Coffee provides one huge boost of energy. It also has some impressive health benefits, such as reducing your risk of developing type 2 diabetes, protecting against dementia, and fighting depression.

However, the energy that coffee provides is short-lived. It peaks quickly, then drops off before you even realize what happened. We've coined this the "caffeine crash". It leaves you irritable and gasping for another cup of coffee.

In terms of caffeine, coffee provides a decent hit:

  • A brewed cup of coffee, made using a coffee maker or French press, contains 96mg of caffeine,
  • A single shot of espresso, made with a true espresso maker, contains 64mg of caffeine,
  • A latte or other coffee beverage made with a double shot of espresso will contain 128mg of caffeine - adding milk doesn't boost or reduce the caffeine content.

But without L-Theanine and catechins, green tea provides a healthier and more natural boost of energy that won't fry your nerves at the same time.


Energy Drinks

Energy drinks come in all shapes and sizes, but most contain a considerable amount of caffeine, often through tea extract. Besides caffeine, many also use sugar to provide a boost of energy.

As we recently explored in our article about Green Tea Energy Drinks, sugar can actually increase fatigue and reduce concentration just 30 minutes after consumption.

If you do opt to consume green tea in the form of an energy drink instead of brewed teas or coffee, check the ingredients list carefully. Choose one that’s sugar-free with plenty of caffeine, L-Theanine, and natural flavors instead of artificial flavors, colorings, and preservatives.

traditional white teacup

Green Tea and Caffeine Health Benefits

Caffeine has numerous effects on your body. Some of the worst side effects range from heart palpitations to uncontrollable jitters and anxiety. However, small amounts of caffeine in combination with antioxidants and other micronutrients naturally contained in tea, can have great benefits instead.


Blood Pressure

Studies have found that green tea has a beneficial effect on blood pressure. The polyphenols found in caffeinated green tea significantly lower both systolic blood pressure and diastolic blood pressure.

The dangers associated with high blood pressure include an increased risk of heart attack and stroke. A cup of green tea each day could help to lower your blood pressure and reduce the stress on your cardiovascular system.


Blood Sugar

Green tea could help you control and manage your diabetes by regulating your blood sugar and improving insulin sensitivity. Furthermore, research in Japan found that those who drink 6 or more cups of green tea per day were less likely to develop type 2 diabetes by a third, compared to those who drank just one cup per week.

One study found that the antihyperglycemic properties of green tea may be caused by a certain serum protein, which needs further exploration.

While green tea could have positive effects on diabetics, maintaining a healthy diet is still important!


Weight Loss

Drinking green tea is often associated with weight loss. This isn't just an old internet myth, there is evidence that regularly consuming green tea can assist both weight loss and weight management. The combination of EGCG and caffeine is highly beneficial for your body when you're aiming to burn fat. One study found that consuming high doses of green tea resulted in significant weight loss in obese women.

However, it should be noted that a review of green tea weight loss studies found that overall, green tea had a statistically non-significant impact on weight loss and weight management. So, you'll still need to put in the effort to lose weight!


Heart Disease

Green tea is effective at reducing heart disease risks in a number of ways:

  • Weakly acidic polyphenols in green tea could dissolve calcium oxalate, which is considered a major cause of heart disease,
  • Alkaloids in green tea could form salts with acids, which will reduce the local concentration of strong acids that are mutagenic and/or carcinogenic,
  • Regularly consuming caffeine could also protect your heart (although the evidence for this stems from coffee consumption).

Along with a healthy diet rich in fruits and vegetables, regular green tea consumption can protect against coronary atherosclerosis.


Immune System

Green tea can support the immune system in numerous ways. Besides protecting against heart disease, assisting weight loss and reducing blood pressure, green tea may also have anti-cancer effects.

Studies have found that green tea catechins could protect against cancer through multiple mechanisms, including "anti-oxidant activity, cell cycle regulation, receptor tyrosine kinase pathway inhibition, immune system modulation, and epigenetic modification control."

A study exploring how combining green tea polyphenols with added vitamins and other nutrients can create anti-cancer effects, discovered that these combinations where particularly effective:

  • Quercetin, curcumin, green tea, cruciferex, and resveratrol - inhibit the growth of Fanconi anemia head and neck squamous cell carcinoma,
  • Polyphenols (quercetin and green tea extract) with vitamin C, amino acids and other micronutrients - suppress ovarian cancer tumour growth.

This is promising news for cancer prevention and treatment.

P.S. If you'd like to boost your immune system but need to avoid caffeine, we have a new Herbal Immunity Blend at Zest Tea.

woman hiking with zest sparkling energy tea in her backpack

Summary - Green Tea Energy

Green tea provides a small but effective boost of energy that you can use to do more with your day. There's always room for improvement, however. Check out Zest's green tea blends to learn more.



  • Great source of nutrients,
  • Helps you rehydrate,
  • Good for losing weight and improving your health,
  • Provides a small amount of energy,
  • Plenty of L-Theanine to boost creativity and prolong the energy burst.



  • Relatively small dose of caffeine per cup,
  • Plain green tea isn't going to taste great to everyone (especially ex-coffee drinkers),
  • Can't typically be consumed with milk.


Zest Green Tea

Our green tea leaves are a little different. Whether you opt for loose leaf tea or our biodegradable pyramid teabags, Zest Tea packs more of a punch.

By adding natural tea extract, we can boost the caffeine levels without disrupting all the beneficial nutrients found naturally in green tea. To add a little extra zing for your taste buds, our hot green tea blends come in two flavors: Pomegranate Mojito and Superberry Samba.

If you want to enjoy all the benefits of green tea energy without all the fuss of brewing, our iced energy teas will suit you better. Check out Blood Orange Mango, Cucumber Melon, and Pomegranate Mint.



Camellia sinensis tea leaf

Does green tea give you energy?

Yes, green tea is made from the Camellia sinensis plant, which does contain caffeine. Drinking green tea may provide a small amount of energy, or quite a big boost, depending on the type and brand.

Which green tea is best for energy?

Zest Tea's green tea blends provide the most energy (caffeine), followed by matcha tea, and then most other forms of green tea. All green teas provide both caffeine and L-Theanine which is the magic recipe for an energized and productive day!

Does green tea help with fatigue?

In most cases, yes. If you experience fatigue and a great big energy crash after your usual cup of coffee, then green tea can help reduce this thanks to the caffeine and L-Theanine combo. Green tea is also great for relieving stress and unwinding. Thanks to the low caffeine content, it can be consumed fairly late in the afternoon/evening too, so it's a perfect choice to unwind with after a tiring day at work.

If you think you may have chronic fatigue syndrome, you should talk to your doctor about a suitable treatment (that may or may not contain green tea).

Which tea gives the most energy?

Zest Tea's Black Tea contains the most caffeine, at 150mg per cup, followed by Zest Green Tea at 135mg. Matcha and yerba mate are also two of the most energizing teas, besides tea-based energy drinks.

Is green tea calming or energizing?

Green tea is both calming and energizing. Green tea provides a small amount of caffeine, which gives you energy. It's also a great source of L-Theanine, which promotes calmness and focus. Together, they give you controllable, steady energy and a calm, alert state of mind.

How much green tea should I drink a day?

Green tea may contain a small amount of caffeine or quite a bit, depending on the type, variety and brand. According to the FDA, you should limit your daily caffeine consumption to 400mg. That's a lot of fresh, natural brewed green tea... and not much at all for green tea energy drinks. Zest Tea's green tea blends contain 135mg per cup.

Can I drink green tea on an empty stomach?

Yes, you can drink green tea on an empty stomach. However, some people find that the strong grassy flavor, acidity, and caffeine on an empty stomach can be uncomfortable. You might feel a little nauseous and the sudden rush of caffeine may make you a little dizzy. We recommend a healthy breakfast (even if it's just a snack on-the-go) to eat with your first tea of the day.

Who should not drink green tea?

Green tea energy is quite low in comparison to most caffeinated teas and beverages, so it should be fine to drink even if you are overly sensitive to caffeine. If you are pregnant or take any medication that caffeine could interact with, you should talk to your doctor about how much green tea is safe to drink each day - or if you should avoid it completely.

PLANT POWERED ENERGY DRINKS  We get it - you can't function before caffeine hits your bloodstream. Good thing Zest has more caffeine than coffee, plus your stomach won't hate you for drinking it.   ENERGY: 150 mg caffeine - more than coffee FOCUS: L-Theanine for all-day, steady alertness HEALTH: Low to no surgar, and made with completely natural ingredients  SEE PRODUCT PAGE


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