There are three treasures in Chinese medicine, Jing, Chi (prana) and Shen. Reishi is the strongest in the Shen catatory of the 3. Which is your spiritual energy.
The first time I tried it reminded of some elements of cannabis. But it's not a psychedelic at all. These spiritual elements seemed to grow stronger after a few days of taking it.
Here is a how I describe it. You feel very immune to negative thoughts and negative influences. It's very protective. It's like all that stuff just doesn't bother you. It also seems to make spiritual practices a lot easier. There is also a lot of health benefit from it too.