Mulungu grows natively in the tropical wetlands of South and Central America. The bark and root of the tree have been used by indigenous people to promote relaxation. If you haven?t heard of it before, you?re not alone. Aside from appearing in a limited number of nutritional supplements, mulungu bark hasn?t gotten a lot of mainstream attention in North America. Now, however, Western herbalists are beginning to use and recommend it more. Not only does it have mood-elevating effects, but it also supports healthy sleep patterns.