Exclusive Chaga tea of Rejuvenation System



2g x 30 packets 4,644 JPY (tax included)

We continue to pursue true health and beauty, celebrating our 20th anniversary in the spring of 2020. We have adopted a unique manufacturing method for Chaga, which has been carefully added to the supplement ingredients of Rejuvenation Co., Ltd., and have arrived at the tea \"RETHÉ\" that you can enjoy every day. Chaga cells contain abundant blessings of strong vitality nurtured in the harsh Russian nature, but they are wrapped in a hard cell wall and cannot be digested and absorbed. \"RETHÉ\" was finally born by sticking to a unique manufacturing method using a patented manufacturing method so that the blessings of nature, which is the vitality of Chaga, can be fully absorbed. It goes without saying that Chaga is good for health and beauty in various documents. The most distinctive feature of RETHÉ is the evidence that Chaga's attractiveness and usefulness can be numerically indicated by inspection.
Inspection results
And above all, safety and security We promise to deliver the confirmed products. It is undeniable that Chaga, which grows in a natural environment over 10 to 20 years, may contain dangerous harmful substances, such as recent environmental problems and nuclear power plant accidents in Russia and Japan. .. Thorough analysis and inspection has made it possible to deliver safe and secure Chaga tea.

For more information on Chaga, click here.

Notice of RETHÉ New Manufacturing Method

The new RETHÉ is rounder, smoother, sweeter and more delicious. It's a taste that I'd like you to try by all means!

Chaga and mushrooms contain a lot of oxalic acid (an astringent and bitter taste that is also contained in vegetables such as spinach and bamboo shoots). Accumulation of oxalic acid causes urinary calculi.

New Chaga Tea Lite: Granulated with calcined calcium. Calcined calcium binds with oxalic acid and has the effect of suppressing the absorption of oxalic acid into the body.

commitment to calcium

Calcined calcium is superior in adsorption of synthetic chemical substances and harmful heavy metals compared to ordinary calcium. At Rejuvenation, based on the technology cultivated through the research of Veggie α, a vegetable cleaning agent, calcined shell calcium derived from scallops is made into fine particles and dissolved in tea to suppress the absorption of oxalic acid into the body. It is also useful for adsorbing bad oils such as lipid peroxide, synthetic chemicals and harmful heavy metals.

Since it is something you drink every day, we are committed to safety and security, and we strive to improve the quality of our products in order to help your health as much as possible.

Winner of the Monde Selection 2023 Silver Award

YouTube Play

Monde Selection

Monde Selection certifies the quality of our products. Since 1961, Monde Selection has evaluated the quality of consumer products around the world, with 80 international experts conducting a 360 ° quality evaluation in a completely independent manner. Each product is individually sampled and tested for a number of carefully selected parameters according to product category and consumer expectations. The tests are sensory, scientific and legal, depending on the type of product.


Monde Selection's original approach

Monde Selection, unlike other contests and competitions, does not compare each product to any other product in its category. Monde Selection experts evaluate the intrinsic quality of each product as a whole, according to very accurate and highly diverse criteria.

What is Chaga (Chaga mushroom)?

Chaga (Japanese name: Chaga mushroom) is a type of mushroom belonging to the family Psilocybe subcaerulipes. It grows in cold regions and is mainly produced in Russia. Therefore, it is also called 'Siberian Reishi' and can be found in Hokkaido in Japan. It mainly parasitizes birch trees and grows over a long period of 10 to 15 years. Eventually, it grows to a diameter of about 30 cm and becomes black and rugged. Originally, the sap of birch trees is rich in sugars, amino acids, malic acid, minerals, etc., and is also famous as a raw material for xylitol. It is Chaga that absorbs the components of the birch sap so that it parasitizes the birch and eventually kills the parasitized tree.

Click here for details

Five features of Chaga tea "RETHÉ"


Chaga Tea RETHÉ's commitment to safety and security (Thorough analysis and inspection)

Since we drink it every day, we are particular about the safety of our products. We promise that we will only sell products that have been confirmed to be safe by inspection at Japan Food Research Laboratories.


Inspection based on Ministry of Health, Labor and Welfare guidelines

Chaga, the raw material of RETHÉ, is a mushroom. Mushrooms are known as foods with high levels of detection of radioactive cesium. As of the end of March 2020, many mushrooms are also listed as subject to shipping restrictions in the list of foods subject to shipping restrictions based on the Act on Special Measures Concerning Nuclear Emergency Preparedness.

Measures and current status of radioactive substances in food (Japanese only)

34 years (as of 2020) have passed since the Chernobyl nuclear accident in April 1986. Although the regulated nuclide, cesium-137, has finally reached its half-life period, it goes without saying that the amount of radiation emitted is only about half, and it still affects the human body. Russia, which is the origin of Chaga, is an area where the effects of Chernobyl-derived nuclides are a concern, so careful inspection is required.

Because RETHÉ is used as tea, the standard value is applied based on the data of the Ministry of Health, Labor and Welfare, "tea conforms to the standard value of drinking water after drinking after being manufactured and processed." Specifically, the passing standard value is 10 becquerels or less per kg, which is the standard for drinking water.


Radiological test results and 450 agricultural chemicals test results

Because it is a natural product, we inspect 450 types of pesticides and radioactive substance detection inspection for each production.Chaga grows naturally on birch trees and grows over 10 to 20 years. Due to unpredictable accidents at Chernobyl and Fukushima nuclear power plants over many years, pollution such as PM2.5 due to environmental problems, the possibility of containing invisible harmful substances, and storage after harvesting There is a danger that it may be harmful to the body, such as chemicals.

RETHÉ analytical test results

The pursuit of quality in Chaga RETHÉ

The most important research subject in pursuit of health and beauty is to condition the body. Chaga has an exceptional health potential. The feature of RETHÉ is to ensure the usefulness of Chaga by a special manufacturing method using a patented manufacturing method. According to the inspection results of the Japan Food Research Laboratories, RETHÉ got41,000 units/g result. This value is 900 units/g ~ 1,000 units/g in normal chaga increments. It is low, and only by adding special processing, it is possible to reach a high concentration value. In addition, we succeeded in obtaining very good results in the Avanced Glycation End products production suppression test by the original method. According to the test results of the Japan Food Research Laboratories, RETHÉ got 70% at a concentration of 80 mg / mL. We have obtained very strong results. With ordinary chopped chaga, it was 26% at a concentration of 100 mg / mL . RETHÉ's commitment is to research materials and repeat inspections to manufacture products of reliable quality.

Using the cell wall destruction powder

The β-D-glucan contained in Chaga has a structure that is a polymer in which many sugars are linked like a chain. Hence it has the character of being difficult to dissolve in water even when it is boiled. Destroying the cell wall of Chaga, is a special patent method which is done only by our company. This action allows the nutritions such as: β-D-glucans to be absorbed in the water. Once it has been absorbed in the water, it can be fully consumed and digested.

Superoxide scavenging activity of Chaga (Chaga mushroom)

Chaga contains many ingredients that are useful for the body. At RETHÉ, we thoroughly inspect and analyze the materials used in our products, work to improve the highest quality, which is also the policy of the rejuvenation brand, and deliver it to everyone with the correct information.


A major feature and attraction of Chaga is its surprisingly high health. As shown in the above material, there are only about 1000 units when examined in the unprocessed state of Chaga. So what is a 35,000-unit chaga that is 35 times more expensive? The powder obtained by concentrating and drying the liquid obtained by boiling chopped chaga is the extract powder. 1g of the powder exceeds 35,000 units. Of course, the extract powder, which has 35 times the value of chaga mushrooms, is a very very expensive material. Our Chaga tea RETHÉ uses original processing to add the extract powder and the cell wall destruction powder, which is also a patented manufacturing method, to the strong numerical value of 41000 units, which is impossible with chopped chaga alone, and the tasteful and rich circle. We have realized the deliciousness.

Click here for useful ingredients of Chaga

Results of Avanced Glycation End products production suppression test of Chaga (Chaga mushroom)


We also have test data for usefulness tests, but we do not open it to the public due to the Pharmaceutical Machinery Law.

Difference between crushed powder and destroyed powder

粉砕末 The crushed powder is a hard Chaga which has been crushed into a powder form. As you can see by comparing with the micrograph, the fiber remains the same state. The difference with the cell wall destruction is that you can not consume the nutritions such as; SOD enzyme and β-D-glucan. This is due to the method which crushes from the outside of Chaga’s cell.
破壊末 The cell wall destruction powder is a special process that destroys the hard cells of Chaga by applying pressure from the inside. As you can see from the micrograph, you can identify that the cells are finely broken into minuscule particles. The solid cells of Chaga contains various valuable nutrients such as β-D-glucan, lignin, and polyphenol, as well as SOD enzyme.
Learn more about chaga shapes and their characteristics here.

Our exclusive manufacturing method ・(Chaga cell wall destruction powder)

The cell walls of Chaga are so hard that they cannot be consumed and digested. In order to efficiently dissolve the nutrient components of Chaga in water, the cell walls of Chaga has been destroyed using special machinery and technology. By destroying the cell walls, various nutrients such as SOD enzyme, β-D-glucan, lignin, inositol, flavonoids, dietary fiber, minerals and vitamins will dissolve in water. After this process, you can enjoy the benefits of Chaga.
Before destruction
After destruction

Frequently Asked Questions

What kind of tea is Chaga tea?

A tea made from precious mushrooms that grow on a birch tree over 10 to 15 years.

Does Chaga smell or taste?

Chaga is almost tasteless and odorless, has less habit than bancha, and is easy to drink. Click here for Chaga recipe

What nutrients does Chaga tea contain?

It contains SOD enzyme, β-D-glucan, lignin, saponin and betulinic acid.

Chaga has a long harvest time of more than 10 years, so I am worried that it may contain chemicals such as pesticides.

I think that there are concerns about pesticides in everything that is boiled as tea, but RETHÉ conducts 450 types of pesticide detection tests for each manufactured product and provides safe products.

I hear that the black part on the outside of Chaga is more nutritious. Which part is RETHÉ made from?

Since RETHÉ extracts all the nutrients in the cells at a high concentration, we offer products featuring more than 40,000 units of SOD enzyme, β-glucan, and high usefulness, regardless of whether they are outside or inside.

Click here for other frequently asked questions

YouTube Play
YouTube Play

List of dealers of Chaga tea 'RETHÉ'


There are RETHÉ dealers all over Japan. In addition, we are looking for corporate companies from many retailers and sole proprietors who can partner with us.

Click here for store information

Company Profile

Corporate name
Rejuvenation Co., Ltd.
Head office location
Mainichi Shimbun Building 2F, 3-4-5 Umeda, Kita-ku, Osaka, Japan
Date of establishment
March 1, 2004
10 million yen
Representative Director Hiromi Sato
Click here for company profile