Lingzhi, also known as reishi, is the ancient "mushroom of immortality", revered for over 2,000 years.
Because of its bitter taste, lingzhi is traditionally prepared as a hot water extract product for use in folk medicine. 
Thinly sliced or pulverized lingzhi (either fresh or dried) is added to boiling water which is then reduced to a simmer, covered, and left for several hours. 
The resulting liquid is dark and fairly bitter in taste. The red lingzhi is often more bitter than the black.
The process is sometimes repeated to increase the concentration. Alternatively, it can be used as an ingredient in an extract (in liquid, capsule, or powder form).
Possible health benefits:
1 - Boost the Immune System
2 - Anti-Cancer Properties
3 - Could Fight Fatigue and Depression
4 - Heart Health
5 - Blood Sugar Control
6 - Antioxidant Status