Why resins follow different extraction rules—and why Frankincense chemistry changes depending on how the resin is prepared.
By Eric R. Cêch | Edited by Anita Felice

Frankincense is one of the clearest examples of why extraction method matters.

Many aromatic plants yield fairly similar results whether they are steam distilled or extracted by other means. Frankincense is not one of them. As a resin rather than a leaf, flower, or peel, it behaves differently during extraction. The resulting products may share a common origin, but they are not necessarily identical in chemistry, aroma, or therapeutic character.

This distinction is important because Frankincense has become one of the most discussed aromatic materials in modern aromatherapy. It is also one of the most misunderstood. Conversations about species, boswellic acids, resin extracts, essential oils, and research findings are often blended together as though they refer to the same material.

They do not.

For readers unfamiliar with CO₂ extraction itself, we explored the broader differences between CO₂ extracts and essential oils in our earlier article on CO2 extraction. Here, we'll focus specifically on Frankincense because few botanicals illustrate those differences more clearly.

What Makes Frankincense Different?

Most essential oils are produced through steam distillation. Water vapor passes through plant material, carrying volatile aromatic compounds into a condenser where they are collected and separated.

This process works beautifully for many botanicals.

Frankincense, however, begins as a hardened resin. Resins contain volatile aromatic compounds, but they also contain larger, heavier constituents that do not travel readily with steam.

As a result, steam-distilled Frankincense essential oil represents only part of the resin's chemistry.

A CO₂ extraction can recover many of the same aromatic compounds while also retaining additional constituents that steam distillation captures less effectively. The result is often a warmer, fuller, and more resinous aromatic profile that many people immediately recognize when comparing the two materials side by side.

Neither preparation is inherently superior.  They are simply different expressions of the same raw material.

Why Frankincense Became One of the First Important CO₂ Extracts

When CO₂ extraction began gaining attention within aromatherapy, Frankincense quickly became one of its most compelling examples.  Practitioners noticed that Frankincense CO₂ extracts often smelled more like the resin itself than the steam-distilled oils. The extracts appeared deeper, richer, and more complete aromatically.

Part of this difference comes from the larger molecular constituents retained during extraction. Certain sesquiterpenes and diterpene alcohols are present in greater amounts than are typically found in the distilled oil.  The chemistry becomes broader.  The aroma becomes fuller.  The material begins to resemble the living resin more closely.

Myrrh presents a similar story. Both are resins, and both tend to reveal characteristics through CO₂ extraction that steam distillation only partially captures.  This is one reason Frankincense and Myrrh have remained among the most respected CO₂ extracts in professional aromatherapy for decades.

Which Fraction of the Resin Are We Trying to Work With?

Much of the discussion surrounding Frankincense becomes easier once we stop asking whether one form is "better" and begin asking a different question:

Which fraction of the resin are we actually trying to work with? 

Steam distillation favors the lighter aromatic compounds that readily travel with water vapor.  CO₂ extraction can recover many of those same compounds while also retaining heavier constituents that are more difficult to carry across through steam alone.  Resin extracts move further still, recovering compounds that are not typically present in aromatic preparations at all.

None of these preparations inherently out rank one another. Each extraction represents a different relationship with the resin. Viewed this way, the conversation becomes much clearer. The more useful question has never been which Frankincense is better, but which Frankincense is in the bottle.

Why the Same Resin Can Produce Different Materials

All three started with Frankincense. All three end with something different!

• The steam distilled essential oil emphasizes the volatile aromatic fraction.
• The CO₂ extract retains a broader range of aromatic and oil-soluble constituents.
• The resin extract may contain compounds not generally present in aromatic preparations at all.

This distinction becomes increasingly important when discussing Frankincense research, therapeutic applications, or product selection.

Many disagreements arise simply because people are discussing different preparations while assuming they are discussing the same one.

A Fuller Resin Profile

One of the more useful ways to think about Frankincense CO₂ is not that it replaces the essential oil, but that it offers a fuller resin profile.  The steam-distilled oil remains beautiful and quite useful.  And truly, a good Frankincense essential oil can be absolutely exquisite.

The CO₂ extract simply emphasizes a different portion of the material. Many people find it less bright, more grounded — closer to the smell of the resin in the hand.

These are aromatic observations rather than value judgments.  Some applications may benefit from one profile.  Others may benefit from another.  The important point is understanding that the difference exists.

Why Frankincense Becomes More Complicated

Frankincense also presents another interesting challenge.

Many discussions surrounding Boswellia focus on species names such as sacra, carterii, and serrata, while others focus on boswellic acids and the growing body of Boswellia research.

Yet these conversations often become intertwined in ways that create more confusion than clarity.  Species, extraction method, resin chemistry, and research preparations are related questions—but they are not the same question. This is one of the reasons Frankincense remains such a fascinating material.

Depending upon the species selected and the way the resin is prepared, the finished product may contain a very different collection of compounds.  Some of the compounds most frequently discussed in Boswellia research are not generally found in Frankincense essential oil at all. Others are strongly influenced by the extraction method used.

In the articles that follow, we'll look more closely at both the species themselves and the chemistry that has made Frankincense one of the most studied aromatic resins in the world.

Here's A Practical Way to Think About Frankincense

For most readers, the question eventually becomes practical. Which preparation makes sense for my intended use?

The answer depends less on which Frankincense is considered "best" and more on what you hope to accomplish.  If your interest is primarily aromatic, meditative, or traditional aromatherapy use, a high-quality steam-distilled Frankincense essential oil remains an excellent choice.

If your interest is a fuller resin profile that more closely resembles the chemistry and aroma of the original resin, a Frankincense CO₂ extract may be worth exploring.

If your interest is driven primarily by compounds discussed in Boswellia research, then the specific preparation becomes especially important—and understanding the differences between essential oils, CO₂ extracts, and resin preparations becomes essential.

These distinctions are not always obvious from a label, yet they are often more important than the name of the species itself.

Final Thoughts
Frankincense remains one of the best examples of why extraction method matters. The resin contains far more than a single preparation can reveal.  Steam distillation shows us one aspect of the material.  CO₂ extraction reveals another.  Additional preparations reveal still more.

None tells the entire story.

The value of understanding Frankincense is not in determining which version is supreme. It is in understanding which Frankincense product is actually being discussed.  Once that distinction becomes clear, many of the questions surrounding species, chemistry, and research begin to make far more sense.

And that is where the rest of this series begins.

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Archive Restoration Note

This article was originally published as What is a CO2 Extract? How Are CO2's and Essential Oils Different? and has been restored from the Ananda archive with updated formatting, references, editorial notes, and current research context while preserving the substance of Eric R. Cêch's original work.

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For educational purposes only. These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.

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CO2 Extracts vs. Essential Oils: When Does the Difference Matter?
Explore why Frankincense became one of the most discussed CO₂ extracts in aromatherapy and how extraction method changes the chemistry of the finished material.

The Three Faces of Frankincense

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Xu L, Tian Y, et al. Recent Advances on Supercritical Fluid Extraction of Essential Oils.

https://pdfs.semanticscholar.org/62ef/7a2e5ff023d6b3425aa73994b7cc16ac4a98.pdf

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Rahimi E, et al. Chamomile Extraction with Supercritical Carbon Dioxide. Journal of Supercritical Fluids, 2011.

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The Ananda Apothecary™ Library is in the process of restoring the Ananda archive—more than fifteen years of research, education, and practical experience working with aromatic plants, essential oils, CO₂ extracts, and botanical medicine. Additional articles continue to be restored and republished as part of this ongoing stewardship project.

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