Panthenol (provitamin B5)

Panthenol is the alcohol form of pantothenic acid, vitamin B5. Provitamin means it is not the vitamin yet: skin converts it after it is applied. That conversion is the reason this form is used rather than the acid itself — it is the more stable of the two in a water-based formula, and it does not have to arrive as the finished article.

It is a humectant, which places it with the hyaluronic acid and the snow mushroom rather than among the actives.