Frankincense is the aromatic resin derived from trees of the Boswellia genus, a substance historically valued across global cultures for thousands of years. This fragrant gum has been used since antiquity in religious ceremonies, as incense, and in various traditional healing systems. The term “frankincense” does not refer to a single product but rather an entire family of resins, each with a unique chemical fingerprint. Determining which species is “best” depends entirely on its intended application, whether that is for internal supplementation, topical skin application, or aromatic diffusion.
The Four Primary Species of Frankincense
Four species of Boswellia dominate the global frankincense trade, each originating from specific arid and mountainous regions. The species Boswellia sacra is often called “Royal” or Holy Frankincense and is primarily harvested from the Dhofar region of Oman and parts of Yemen. Its resin is highly prized for its pale color, sometimes appearing milky-white or pale yellow, and it carries a distinctively sweet, citrusy, and spicy aroma.
Another widely distributed species is Boswellia carterii, which grows throughout the Horn of Africa, particularly in Somalia and Ethiopia. The resin from this tree is one of the most common sources for essential oils and is known for its fresh, woody, and slightly citrus aroma profile. While historically sometimes confused with B. sacra, recent chemical analysis suggests they are distinct species or ecotypes.
Indian frankincense, derived from Boswellia serrata, is native to the dry mountainous regions of India and is a cornerstone of traditional Ayurvedic medicine. This species is characterized by a warm, spicy, and woody scent when burned and is the form most often used in modern dietary supplements. The fourth major species, Boswellia frereana, is native to northern Somalia and is often nicknamed “Maydi” or the King of Frankincense by locals.
B. frereana produces long, golden, and translucent resin tears, which are traditionally favored for chewing for oral health and digestion. Its aromatic profile is distinctively sweet and peppery, setting it apart from the classic balsamic notes of the other species.
Chemical Differences and Targeted Uses
The functional difference between the species is rooted in the ratio of two primary chemical groups: the volatile components and the non-volatile components. The volatile components are the monoterpenes and sesquiterpenes, which are captured during steam distillation to create essential oils. These compounds, such as alpha-pinene and limonene, are responsible for the resin’s aroma and are easily absorbed through inhalation and topical application.
For aromatherapy and topical skin care, the essential oils of B. sacra and B. carterii are favored due to their complex volatile oil profiles. For instance, B. sacra oil is rich in alpha-pinene, which contributes to its calming and grounding effects. In contrast, the resin of B. frereana is distinct because it contains a very high concentration of monoterpenes but often lacks the non-volatile boswellic acids entirely, making it purely an aromatic and topical choice.
The non-volatile components are a group of triterpenoids known as boswellic acids, which are large molecules that do not pass into the essential oil during steam distillation. These acids, particularly 3-O-acetyl-11-keto-β-boswellic acid (AKBA), are the primary anti-inflammatory agents. To gain the systemic benefits of these compounds, the resin must be extracted using solvents and consumed as a supplement.
The species Boswellia serrata is the industry standard for internal supplementation because its resin naturally contains a higher concentration of these therapeutic boswellic acids. Therefore, if the goal is to reduce internal inflammation, a standardized extract of B. serrata is the appropriate choice, while a steam-distilled essential oil from B. sacra is better for aromatic or diluted topical use.
Selecting the Best Form and Quality
Once the appropriate species is identified based on chemical profile, the next step is selecting the correct commercial form for the intended use. Frankincense is available primarily as resin tears, essential oils, or standardized extracts. Resin tears are the oldest form, which can be burned as incense for aroma or chewed for oral benefits, providing a full spectrum of both volatile and non-volatile compounds.
Essential oils are produced via steam distillation and are best for diffusion or topical use when diluted with a carrier oil. Since essential oils lack the therapeutic concentrations of boswellic acids, they should not be confused with the internal supplements designed for anti-inflammatory effects. Standardized extracts, typically in capsule form, are concentrated solvent extracts of the resin and are the most effective way to guarantee a therapeutic dose of boswellic acids for internal use.
Ensuring the quality of any frankincense product requires looking for third-party testing. For essential oils, suppliers should provide a Gas Chromatography-Mass Spectrometry (GC/MS) report, which verifies the exact chemical composition and confirms the product’s purity. This testing helps to prevent adulteration, such as cutting the oil with cheaper solvents or synthetic compounds.
The Boswellia trees are slow-growing and face threats from over-tapping and habitat loss. Choosing products from companies that emphasize sustainable harvesting practices supports the long-term health of the trees and the preservation of high-quality resin. Ethical sourcing is an important marker of a responsible frankincense product.