The bark of the tree which is the most famous of all of its parts is astringent (viz contractive to living tissues and hence helpful in healing of the wounds) and a well reputed febrifuge or a destroyer of fever. The outer layer of the bark is richer in this astringent substance while the inner layer is richer in the bitter substance which also happens to be acidic.
The bitter substance is less in quantity in the leaves and this is also more quickly and abundantly soluble in water than what is obtained from the bark. Pimples will be cured by applying a decoction of neem bark and amaltas together.