In recent years, the craze about Oolong tea has emerged, especially among young people, in many countries. If you like the tea and are wonder “Is oolong tea safe?”, here is where you can find a reliable answer from tea experts.

We know for a fact that oolong tea, like most other tea, is made from leaves of the Camellia Sinensis plant. With the distinctive semi-oxidation process, oolong tea has many beneficial properties and is able to bring great boons if used correctly. Let’s explore in-depth this wonderful beverage in our post.

oolong tea is safe for drink

1. The safety of drinking oolong tea

First and foremost, there is currently no scientific research that suggests that oolong tea is harmful to your health. However, due to the certain content of caffeine in tea, overconsumption will definitely lead to some side effects.

The caffeine content in oolong tea is heavily dictated by its semi-oxidation process: the more oxidized the tea, the less caffeine it will have. You can tell the oxidation level of oolong tea by its liquor color. Therefore to keep it simple, the greener the tea liquor, the more caffeine it has; the redder the tea liquor, the less caffeine it has.

caffeine level of oolong tea based on the color of the water
You can recognize the caffeine level of oolong tea based on the color of the water.

According to FoodData Central by the USDA, a 100g of Oolong tea has 38mg of caffeine while the safe consumption threshold is 400mg a day (200mg for pregnant women). We know for a fact that this data is a huge assumption and generalization by the USDA. However, to be safe, you shouldn’t drink over 1 litter of oolong tea a day (500ml for pregnant women).

The side effects of crossing this threshold can include: Stress, high tension, loss of sleep, headache, fast heartbeat, nausea, etc.

Related post: Does Vietnamese lotus tea have caffeine? Facts you should know

2. Health benefits of Oolong tea

If you have a little bit of worry about the safety of oolong tea, we will confirm that it doesn’t matter when drinking properly. Not only that, you can get many benefits for your health by drinking oolong tea. It is an undeniable fact.

Here are some of the wonderful benefits that oolong tea has to offer:

2.1. Improve brain function

Caffeine in oolong tea helps increase brain function temporarily. It also aids the production of dopamine and norepinephrine to improve mood and attention. (1) Aside from caffeine, tea also contains theanine, and many other antioxidants which increase attention, relieve anxiety, lower the risk of cognitive impairment (2) (3)

drinking tea at work
Tea is a great drink when working

2.2. Improve heart health

Oolong tea has many antioxidants that bring significant benefits to the working of their hearts. (4) (5) (6). There are myriads of peer-reviewed studies that support the above statement. These studies produced the same result in countries with high tea consumption, such as China or Japan (7).

Some might argue that oolong tea consumption’s advantages on heart health contradict the fact that tea has caffeine. However, the amount of caffeine in the is significantly lower than coffee (around 4 times to be exact); side effects regarding blood pressure and hypertension will be much less as well.

2.3. Prevent diabetes

There are currently many studies showing that polyphenol antioxidants’ benefit in blood sugar management as well as type 2 diabetes prevention (8) (9). These polyphenol antioxidants are present in all tea, including oolong tea. Depending on the processing method of oolong tea, the level of polyphenol may vary, however, more research will be needed for us to claim anything with certainty.

2.4. Support weight loss

Along with controlling blood sugar levels, oolong tea is proven to prevent obesity. In a Chinese study, 70% of overweight patients have lost 1 kg of fat only after 6 weeks of daily oolong tea consumption alone (10)

drinking oolong tea
Properly drinking oolong tea will improve your health every day.

2.5. Promote tooth and bone strength

The antioxidants present in oolong tea can be versatile. One of its not very well-known benefits on health is that it keeps your bone strong. Daily consumption of oolong tea can aid the overall bone density of drinkers. (11) This means oolong tea can also help prevent fractures of bones.

In short, oolong tea is safe and also bring a lot of health benefit for you if it is drunk in the right way. We will give some notes that help you both enjoy fully oolong tea and get these boons for health.

Click here if you want to import high quality Vietnamese oolong tea

3. Guide on drinking Oolong tea safely

Even though I’ve mentioned some of these points above already, I still want to give you a rundown on all the tips to drinking oolong tea safely:

  • First of all, choose your oolong tea wisely. If you are sensitive to caffeine, choose one of those dark red or roasted oolong tea. Due to heavy oxidation, this tea will have much lower caffeine compared to green oolong tea.
  • Secondly, you should avoid drinking before meals and at night. Because, your body is quite susceptible to caffeine these times, so it makes side effects more likely to happen. These can lead to high tension or nausea.
  • Last but not least, like mentioned above, limit yourself and drink less than a liter (500ml for pregnant woman) a day.
Green Oolong Tea (left) and Red Oolong tea (right)
Green Oolong Tea (left) and Red Oolong tea (right)

Related post: How to make Vietnamese tea – A guideline to enjoy our tea easily!

If you are looking for Oolong tea to distribute in your market, feel free to contact us at We at FGC is the top Vietnamese tea exporters with many tea plantations all over Vietnam. We are your one-stop-shop for tea and we will surely satisfy all your tea needs!

Above is the answer for “Is oolong tea safe“, we hope that you can use oolong tea effectively and gain the best health benefits from this delicious drink.

Author: Mr. Bach Doan – Marketing Manager (

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