Is Reishi Mushroom Something You Eat?

I would like to know if this product Reishi Mushroom is something one can eat and is there any special way one must prepare it. Or can it be used without any special preparation? How does one use it?

Reishi mushroom, also known by its Chinese name, ling zhi, or by its botanical name, Ganoderma lucidum, is edible in the sense that it does no harm when ingested orally. But it is very bitter and cannot be used as a food like other edible mushrooms such as the shiitake and oyster mushrooms. When it is eaten it is generally added to other foods as a way to supplement the diet with reishi's considerable tonic and immune-boosting properties. Probably the easiest approach is to dry the mushroom and grind it into a powder. The dried powder can be added to foods surreptitously by sprinkling the powder on strong tasting foods. Some people develop a liking for the bitter taste and are able to tolerate it well.
Because of the bitterness, reishi is usually taken nowadays in capsules. You can fill your own capsules. Empty capsules are often available at the drugstore and these are simply filled with dried powder and taken as a supplement.
One of my hobby horses is the importance of bitter principles in the diet and how the modern diet is so bereft of bitterness now. Bitter principles are key to stimulating the digestive system into action, and with that comes a whole host of tonic effects on the body. Traditional "spring tonics" are typically bitter and they help get our lethargic systems back in shape after a long winter.
Another way to ingest reishi is to make a tea. Here is a simple recipe (from The Mushroom Growers' Newsletter, December 1994): in a small pan with 1 cup of water add 1 tsp of chopped dried reishi and 7 thin slices of fresh ginger root. Bring to a boil, simmer for 10 minutes or so, and strain.