Betulin is natural crystal and chemical (it is a triterpenic alcohol), found in birch bark (Betula ), from which comes its name. Although widespread in nature, Betuline as a chemical was obtained by extraction of the outer layers of birch bark by Löwitz in 1788 as pure chemical substance.It took several decades before its structure could be determined.

The white colour of birch bark is mainly caused by betulin, which gives it  specific properties, such as never rotting, which is prevented by the anti-mould and antibacterial properties of betulin. It is natural agent against pests and micro-organisms, which is just as well, since the birch tree is host to thousands of these!