What is LEM  The extract from the cultured solid medium of Lentinus edodes mycelia.Since 1969.

"LEM®” is the extract from solid medium cultured with Lentinus edodes (shiitake) mycelia. The extract has obtained from crushed shiitake mycelia cultured solid medium by physically special technique after the mycelia of shiitake are cultured on solid medium consist of food materials. Main Ingredients are water-soluble lignin (Low-molecular-weight lignin), polysaccharides, proteins and minerals.
The aqueous solution and granule containing LEM® are given permission to manufacture and sell by Japanese authority based on the Food Sanitation Low from 1972. Then these products are selling under a trade name “SHIIKIN”, “JOGEN” as a health food and are having a strong following of users.



The results of monitoring the purpose of taking of these products, it was revealed that it is taken for the purpose of relieving the pain associated with terminal cancers, and treatment for viral hepatitis and so on, in addition to the habitual use as health food. Moreover, many reports about the efficacy of these products were received from users. Then we started fundamental scientific research about LEM®.
As a result, in animal testing, it showed that LEM® had the suppressive effects on hepatic tumorgenicity and transplantation tumor growth. These findings were presented at the Pharmaceutical Society of Japan Hokuriku branch in June 1981. In the subsequent researches, it was found that LEM® had the inhibitory effect on colorectal carcinogenesis. Furthermore, it was revealed that LEM® suppressed hepatic metastasis of the malignant tumor.

These activities of LEM® was not direct action against cancer cells but through host-mediated immunoregulation activity. It was recognized that LEM® induced production of IL-1, IL-2, IL-12, TNF-a, IFN-r and NO in the results of in vitro and in vivo experiments.  


In the case of human disorder, the effectiveness and safety of LEM® for Hepatitis B had been studied by medical specialists. A decrease in e-antigen, DNA polymerase activity, GOT and GPT, and an increase in e-antibody were found from the analysis results of HBe Antigen positive chronic hepatitis patients (106 cases). No severe side-effect was observed with the exception of a few mild digestive disorders. In parallel, the foundation examination of its immunological activities had been conducted. As the results, inhibition of immune-mediated hepatocellular damage and potentiation of antibody production were found. On the prolonged oral administration of LEM® to wood-chuck (model animal for Hepatitis B), inhibition of wood-chuck hepatic virus multiplication and improvement of hepatic dysfunction were found.

Based on these studies, the effects of LEM® against Human Immunodeficiency Virus (HIV, causal agent of acquired immunodeficiency syndrome) had examined. As a result, it was found that LEM® had the ability to inhibit HIV infection to host cells, infection in co-culture system. In addition, LEM® had the ability to inhibit cytopathic effect, reverse transcriptase activity.

Evidence of the power of “LEM”  
- Water-soluble lignin -

LEM has 2 types of bioactive components, polysaccharides (xylose-containing heteroglycans) and water-soluble lignin. The unique characteristic of LEM is that it contains water-soluble lignin, which is not contained other common mushroom products. Lignin is present in the cell walls of plants and is not soluble in water because of high-molecular-weight. Lignin is difficult to digest even if humans eat. However, Lignin has become soluble in water through degradation by specific enzymes produced from shiitake mycelia in the process of cultivating shiitake mycelia on solid medium. This water-soluble lignin has immunoregulative, antiviral and antioxidative activities.


There have been many reports about anticarcinogenic action of Basidoimycetes Sp., but these reports are mostly about β-glucan fractionated from fruits body or mycelia , and these substances have immunopotenciate ability but no anti-viral activity. At the test on animals, most of data was not in the case of oral administration of mushroom itself but in the case of injection of fraction.
Active substances of LEM, different from those just described above, is a complex polymer; proteoglycan with highly denatured water-soluble lignin, the culture which is digested by specific enzyme of Siitake mushroom and decomposed. It is found LEM had immunomodulating action and anti-viral action, additionally anti-oxidation to scavenge free radical or active oxygen, especially, to scavenge OH radical which is the most powerful active oxygen.

 As it is described above, LEM shows host mediated immunopoteiciation, anti-viral activity and anti-oxidation activity with extremely safety on the test of animals, and with almost no side-effect foe human beings, based on the result of the long period administration clinical test. From all of these clinical studies, it is found LEM, with its long period administration, activates the immunopoteiciality gradually and balances the homeostasis, as well as that LEM is effective health food for viral hepatitis with safety. 

What is the function of LEM®?

Since LEM (registered trademark) is an immune modulator, it is mainly used by people with reduced immunosensitivity. A patient undergoing conventional cancer treatment. For this reason, LEM® is commonly used in clinics and facilities as part of an integrated or complementary approach, along with traditional treatments.

Where is LEM® Made?

While products containing LEM® are sold all around the world, the raw material used in their production is made nowhere else but our factory.



Safety and reliability of “LEM”
- Safety of LEM -

Shiitake using for manufacturing of LEM has been traditionally used as food. Therefore, it is considered safe for use. In addition, the safety of LEM has been proved on various safety test (e.g. toxicity and mutagenicity tests) by specialized institutions. Based on these results, LEM is considered to be safer than sugar.

Acute Rats(male)
16,400 mg/kg
19,600 mg/kg
Subacute toxicity
(three months)
3,840 mg/kg/day
6,740 mg/kg/day
Mutagenicity Nerative (in Ames test, Rec-assay, and umu-test)
Skin sensitization   Negative
Aquatic animals  LC50 Carp 906 mg/kg(96hr)
Water flea 513 mg/kg(48hr)

LD50: Median Lethal Dose (< 50 mg/kg: Poisonous substances, 50-300 mg/kg: Deleterious substances)
NOEL: No Observed Effect. Level
LC50: Median Lethal Concentration