Camellia Sinensis Leaf Extract: Main Compounds, Benefits, Side Effects and Uses

The tea plant, also known as Camellia sinensis, produces black, green, oolong, and white tea. The oil from the plant’s leaves is known as the leaf extract.

Camellia sinensis leaf extract, which contains the plant’s beneficial compounds in a concentrated form, has become popular due to the numerous health benefits associated with tea, particularly green tea. You can make the extract at home or purchase it as a supplement.

This article examines Camellia sinensis leaf extract in more detail, exploring its health benefits and common applications.

Main compounds

Here are some of the primary bioactive compounds found in Camellia sinensis leaf extract, responsible for tea’s aroma, flavor, astringency, taste, and medicinal properties:


Catechins, classified as flavonoids and one of the primary active compounds in Camellia sinensis, have been linked to cancer-fighting properties in studies. Flavonoids are a common type of polyphenol, a group of compounds known for their potent antioxidant properties. Antioxidants help neutralize free radicals, harmful molecules that can cause oxidative stress and lead to various diseases.

Camellia sinensis leaf extract contains four different types of catechins: epigallocatechin gallate (EGCG), epigallocatechin (EGC), epicatechin gallate (ECG), and epicatechin (EC). Of these, EGCG is the most potent and predominant.


Caffeine is a well-researched stimulant compound found in coffee and tea. Green tea typically contains about 6% caffeine per cup. It has been associated with both positive and negative health effects.

Studies suggest that regular caffeine intake may help prevent the development of type 2 diabetes, metabolic syndrome, heart disease, dementia, and Alzheimer’s disease. Caffeine may also improve mental functioning, alertness, and exercise performance, while reducing fatigue.

However, excessive caffeine consumption can lead to potentially harmful health effects, such as an irregular heart rate.


L-theanine is a non-protein amino acid that contributes to tea’s flavor and aroma. It’s derived from the tea plant and is the most abundant amino acid in green tea, making up about half of its amino acid content. L-theanine has been associated with a relaxing effect that may improve concentration and learning. Studies have also shown that it has anti-inflammatory and antioxidant effects and is linked to improved immune function.

Other compounds

Tea leaf extract also contains a variety of other compounds such as B vitamins, lipids like linoleic and alpha-linolenic acids, and trace minerals such as magnesium, calcium, iron, zinc, and selenium.

Effects on skin health

Camellia sinensis leaf extract has been widely used in the cosmetic industry for its potential benefits on skin health and appearance. The antioxidant properties of EGCG found in the extract have been shown to protect the skin from damage caused by UV radiation, which can lead to sunburn, premature skin aging, and nonmelanoma skin cancer.

Moreover, both topical and oral administration of the extract have been found to decrease scaling and improve blood flow, skin elasticity, hydration, and density. The caffeine content in the extract also makes it a popular anti-cellulite agent.

Additionally, the extract may help reduce wound healing time and decrease excess sebum production, a common characteristic of oily skin.

Effects on heart health

Camellia sinensis leaf extract or tea consumption may have a positive impact on heart health.

Their catechin and L-theanine content can help reduce risk factors for heart disease, including:

  • Blood cholesterol and triglycerides: Studies suggest that the extract can decrease levels of total and LDL (bad) cholesterol and triglycerides by decreasing their absorption.
  • Arterial plaque: Catechins in the extract can reduce the oxidation of LDL (bad) cholesterol, helping to prevent the buildup of plaque and blockages in your arteries.
  • Blood pressure: The extract may lower blood pressure by promoting relaxation of blood vessels and improving their function.
  • Additionally, the extract may also decrease the risk of heart attack. Its compounds may reduce heart enlargement, improve blood pressure dysfunction, and restore antioxidant enzyme activity.

Anticancer effects

The extract from Camellia sinensis leaves has shown potential in fighting cancer, mainly due to its catechins, especially EGCG.

Studies conducted in test tubes and animals have found that EGCG can induce apoptosis, or programmed cell death, in cancer cells, thus offering cancer-protective effects.

EGCG may also help prevent tumor progression and spread by inhibiting angiogenesis, which is the growth of new blood vessels that could otherwise feed cancer cells.

Moreover, EGCG can increase the activity of antioxidant enzymes in the body, neutralizing free radicals that can damage DNA and lead to cancer development.

Research has shown that EGCG may be beneficial in reducing the risk of several types of cancers, such as low-grade prostate cancer, breast cancer, lung cancer, stomach cancer, colorectal cancer, and liver cancer. In addition, EGCG may also reduce mortality, lower recurrence rates, and increase the cancer-free period in people with stage one and two breast cancer.

Effects on the immune system

Tea extract can boost the immune system, with L-theanine and EGCG playing a key role.

L-theanine can potentially enhance T-cell production, which fights diseases, combating infections, allergic diseases, and hypersensitivity reactions.

EGCG may help restore the body’s immunological balance in autoimmune diseases by decreasing the production of inflammatory markers, and it can improve resistance to infections and act as an antiviral agent. It can inhibit the early stages of infection and block a virus’s life cycle in infected cells.

Effects on stress and anxiety

L-theanine is responsible for the extract’s anti-stress effect. Research indicates that L-theanine increases dopamine and serotonin levels, which are neurotransmitters that regulate happiness and motivation.

Moreover, L-theanine promotes relaxation and decreases anxiety by increasing alpha brain waves. Alpha brain waves are linked with a calm, alert mental state.

Interestingly, a study suggests that the calming effect of L-theanine may be improved when it’s combined with caffeine, which is also present in the extract.

Effects on weight loss

Obesity is a global health issue that can be combated with Camellia sinensis leaf extract. Both EGCG and caffeine in the extract can aid in weight loss by various means.

EGCG can hinder the enzymes responsible for carb and fat absorption and influence gut microbiota. Caffeine can increase metabolic rate, energy expenditure, and fat oxidation. Combining EGCG and caffeine may enhance their effect on weight loss.

However, more research is needed to determine the exact effects of Camellia sinensis leaf extract on weight loss as some studies have found no significant weight loss.

Other health benefits

Camellia sinensis leaf extract offers a variety of health benefits, such as reducing inflammation, improving bone health, and promoting liver health. Animal studies suggest that the extract’s compounds may inhibit the production of pro-inflammatory substances associated with inflammatory diseases like arthritis. Both animal and human studies indicate that catechins present in the extract may help regulate bone metabolism and reduce bone loss. Moreover, the extract’s catechin and L-theanine content may protect against liver injury by reducing liver enzymes that cause inflammation and disease.

Potential downsides

Although generally safe and well-tolerated, Camellia sinensis leaf extract has been associated with some unwanted side effects.

Its caffeine content may cause jitteriness and headaches. Higher amounts of caffeine during pregnancy have been linked to a greater risk of pregnancy loss and low birth weight.

The extract may also cause skin reactions like rash or allergy, and digestive symptoms such as diarrhea and nausea.

More seriously, research has linked the extract to liver toxicity. While very rare, green tea extracts have been known to cause liver damage at doses ranging from 140-2,100 mg per day. This can be exacerbated if taken on an empty stomach, and symptoms of liver toxicity may include dark urine, abdominal pain, or yellowing of the skin and eyes.

Liver toxicity may occur due to high levels of EGCG interacting with medications or an individual’s metabolism.

Therefore, it’s important to consult a healthcare provider before taking Camellia sinensis extract, especially if pregnant, have a health condition, or concerned about liver toxicity. In case of symptoms of liver toxicity, stop taking the extract immediately.

How to make and take Camellia sinensis leaf extract

Scientific research shows that the extract is effective in preventing and treating various conditions, though it is commonly used for weight loss and skin health.

While drinking tea provides some benefits, the extract offers higher concentrations of the active compounds. You can purchase it in powder, capsule, or liquid form online or make your own at home.

To create a homemade, glycerin-based extract, follow these steps:


  • 10 grams of ground green tea leaves
  • 80 mL of glycerin
  • Water


  • Fine filter or food-grade oil filter
  • Airtight, dark-colored storage container holding at least 150 mL


  1. Place 10 grams of ground green tea leaves in a pot on the stovetop and cover with water.
  2. Bring the water to a gentle boil, cover, and boil for 30 minutes to 2 hours.
  3. Strain the extract using a strainer and fine filter.
  4. To dilute the extract to 80% glycerin, add 20 mL of water and 80 mL of glycerin.
  5. Stir well and pour the mixture into an airtight, dark-colored storage container.
  6. Store the extract in the container to prevent light and oxygen exposure.

Note that the extract’s antioxidants are light and oxygen-sensitive. Thus, it’s crucial to store the extract in an airtight, dark-colored container to prevent degradation.

It’s essential to consult with a healthcare provider before using Camellia sinensis leaf extract.

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