Ganoderma lucidum is a species of mushroom that’s long been a staple of traditional Chinese medicine. Also known as Reishi mushroom, when applied to skin, research has shown a compound it contains (ganodermanondiol) can interrupt the enzyme tyrosinase, which in turn can visibly reduce certain types of discoloration.

Research has also shown this extract can improve skin’s supportive elements while also reducing signs of irritation. It’s a natural source of vitamin D2, skin-beneficial trace minerals such as copper and selenium, and the amino acids leucine and lysine.

As with most other types of mushrooms, Ganoderma lucidum is also a very good antioxidant. The extract form of this mushroom eliminates the water component (the whole mushroom that you’d buy in the grocery store contains over 90% water), so only a small amount is needed to get its benefits.
https://www.paulaschoice.com/ingredient-dictionary/ingredient-ganoderma-lucidum-extract.html

This ingredient is not currently on EWG's Skin Deep Restricted or Unacceptable Lists.
https://www.ewg.org/skindeep/ingredients/702541-GANODERMA_LUCIDUM_REISHI_STEM_EXTRACT/