Magnolia bark is used as a general anti-stress and anti-anxiety agent - so its claims typically center on general benefits in controlling stress and anxiety. Newer claims are emerging, however, to link magnolia's anti-stress benefits with control of the body's primary stress hormone, cortisol, and the myriad health benefits associated with normal cortisol levels (versus elevated cortisol, which has been associated with obesity, diabetes, osteoporosis, memory problems and suppressed immune function).
Magnolia bark is rich in two biphenol compounds, (magnolol and honokiol), which are thought to contribute to the primary anti-stress and cortisol-lowering effects of the plant. The magnolol content of magnolia bark is generally in the range of 2-10 percent, while honokiol tends to occur naturally at 1-5 percent in dried magnolia bark. Magnolia bark also contains a bit less than 1 percent of an essential oil known as eudesmol, which is classified as a triterpene compound, and may provide some additional benefits as an antioxidant.