Amateur aromatherapists and home crafters may find the difference between premium cinnamon-bark essential oil and its less expensive sister, cinnamon-leaf essential oil, confusing. The ultimate choice of product depends on the primary use for the essential oil. In some cases, the extra investment in bark oil may be called for, while for other applications the leaf oil may be as good or even a preferable.

Producers of cinnamon-leaf and cinnamon-bark essential oils extract the essences from any of several trees of the Cinnamomum genus. The trees originated in Southeast Asia and grow best in tropical climates. Essential oils are the extracted volatile oils of plants. Cinnamon trees yield fragrant, therapeutic essential oils from both their leaves and inner bark. The inner bark is also used to produce the cinnamon sticks and ground cinnamon familiar to bakers.

As a means of aiding health and controlling pests, cinnamon-bark oil was until recently considered superior to cinnamon-leaf oil, as Jeanne Rose notes in "The Aromatherapy Book." In the 1992 volume, Rose recommends the bark oil exclusively to kill germs and to use in massage oils for boosting circulation. But more-recent research indicated that the active compound, cinnamaldehyde, is equally available from both the leaf and the bark oils. A 2007 study conducted by Spain's Universidad de Murcia found that cinnamon-leaf and cinnamon-bark oil, along with clove oil, contained antimicrobial properties, which the food industry could theoretically use to fight Listeria monocytogenes. Additional research done by the National Taiwan University in 2004 focused on cinnamon-leaf oil's potential use in natural health products. Researchers concluded that the leaf oil has "excellent anti-inflammatory activities." These studies suggest that cinnamon-leaf and cinnamon-bark essential oils may be used interchangeably in at least some applications.

While scent preferences are subjective, perfume houses consider cinnamon-bark essential oil preferable to the lighter, less-intense scent of cinnamon-leaf oil, notes author Mandy Aftel in her book “Essence and Alchemy.” Home crafters may prefer the lighter and less expensive cinnamon-leaf oil for body products and potpourri. The National Association for Holistic Aromatherapy warns that if you do seek the deeper, longer-lasting scent of cinnamon-bark essential oil, check carefully to ensure that the producer hasn’t blended the less-expensive leaf oil into the mixture as a cost-cutting measure.

Cinnamon-leaf oil is less expensive than bark oil, because the tree's leaves are more easily harvested than the inner bark. Additionally, leaves may be gathered from the cinnamon tree without damaging it, while removing the tree's inner bark threatens the sustainability of cinnamon-tree stands. While the food industry utilizes both the leaf and bark oils to flavor colas, candy and other products, home cooks should avoid taking the essential oil internally, opting instead for ground or stick cinnamon.