What it is
Vanillin is a white to off-white crystalline solid responsible for the characteristic sweet, vanilla-like scent of the vanilla bean. In sunscreens and lip products it is added in small amounts to impart a pleasant smell or taste rather than for any functional skin benefit. It can be obtained naturally from vanilla pods or produced synthetically at far lower cost.
Safety & warnings
Vanillin is generally well tolerated at the low levels used for fragrance and flavor. As a fragrance material it can occasionally cause contact sensitization in susceptible individuals, and it is structurally related to other potential aroma allergens; those with known fragrance sensitivities may wish to patch test scented products.
Origin & sourcing
Naturally present in the cured pods of Vanilla planifolia, but the vast majority used commercially is produced synthetically, historically from lignin or guaiacol and now also via fermentation.
History
Vanillin was first isolated from vanilla in 1858 and chemically synthesized in 1874, making it one of the earliest flavor compounds to be produced industrially.
Questions everyone asks
Is vanillin a natural or synthetic ingredient?
It occurs naturally in vanilla beans, but most vanillin in cosmetics is synthesized or made by fermentation because natural extraction is costly.
Does vanillin do anything for the skin?
In sunscreens it functions mainly as a fragrance or flavoring agent and is not added for a direct skin-care benefit.