After polysaccharides, the second-most important active ingredients in medicinal mushrooms are terpenoids. 

Terpenoids is that they are not water-soluble. For this reason, they must be extracted from the chosen mushroom through alcohol extraction. Alcohol extraction is typically done as an additional step after hot water extraction, which is why it is called a dual extract.

For example, the Reishi and Chaga mushrooms contain a significant amount of triterpenoids alongside beta-glucans. As such, dual extraction is necessary to produce a high-quality Reishi or Chaga mushroom extract that contains significant levels of both beta-glucans and terpenoids