Guaiol is a lesser-known terpene found in the cannabis plant, cypress pines, and the wood of the tropical guaiacum plant. Researchers have started studying it in the lab for anti-inflammatory, antibacterial, and anticancer activity.
This article covers what guaiol is, how it smells, where it comes from, and what the early research shows. It also lists cannabis strains often reported to contain guaiol and explains how the terpene is used today.
What Does Guaiol Smell and Taste Like?
Guaiol has a mild woody aroma with a soft rose note. The Good Scents Company, a fragrance ingredient database, describes it as "mild guaiacwood tea rose."
Its scent is closely tied to guaiac wood oil, which contains high concentrations of guaiol. In cannabis, guaiol adds a woody background with soft rose notes rather than a strong, easy-to-name aroma. Because guaiol is not approved as a food flavoring, its taste is not well documented.
Chemical Properties of Guaiol
Guaiol, also called champacol, is a sesquiterpenoid alcohol with the chemical formula C15H26O and a molecular weight of 222.37 g/mol. Its structure has two fused rings, one with five carbon atoms and one with seven.
At room temperature, pure guaiol is a crystalline solid, not a liquid. It melts at about 92°C (198°F) and boils at about 309°C (588°F), according to The Good Scents Company.
That high boiling point means guaiol is much less volatile than other terpenes such as myrcene or limonene. It evaporates slowly, which helps it last longer in fragrances and wood oils.
Potential Health Benefits of Guaiol
Research on guaiol is at an early stage. The studies below were done on cells in a lab or on essential oils that contain guaiol, so they point to possible therapeutic benefits for future research rather than proven effects in people.
Anti-inflammatory activity: A 2023 study tested compounds from banana peel extract on immune cells in the lab. Guaiol at 100 micromolar significantly reduced nitric oxide and the pro-inflammatory cytokines IL-6 and TNF-α, which are signaling molecules that drive inflammation.
Anticancer activity: In lab studies on non-small cell lung cancer cells, guaiol slowed cancer cell growth and triggered cell death. Guaiol has not been tested as a cancer treatment in people.
Antibacterial activity: A 2020 study tested the essential oil of Amyris balsamifera, which was 19.4% guaiol. The oil showed its strongest activity against Staphylococcus aureus, but guaiol itself was not tested separately.
Sources of Guaiol Terpene
Guaiol is named after the guaiacum plant, a group of trees native to tropical and subtropical regions of the Americas. Guaiac wood oil is the richest known source of guaiol, with about 27% of the oil made up of this terpene. The oil is distilled from the wood of Bulnesia sarmientoi, a South American tree also called guaiacwood.
Australian cypress pines (Callitris), which are coniferous trees, have wood oils with roughly 6% to 14% guaiol. Smaller amounts appear in some sage, cajuput, parsley, and pepper essential oils.
Guaiol is also one of many terpenes found in cannabis. It is usually present at low levels in cannabis flower, but lab reports show it in noticeable amounts in some strains.
Strains Reported to Contain Guaiol
Guaiol gets less attention than terpenes like myrcene or linalool, and published strain lists rarely give measured amounts. Terpene levels also vary by grower, harvest, and batch, so a product's lab report is the only reliable way to confirm guaiol content.
Strains often reported to contain guaiol include Haze Berry, Royal Gorilla, ACDC, Sour Berry, and Kali Dog. In any given batch, guaiol may appear only in trace amounts or not be detected at all.
You can explore other strain aromas without THC in our full list of strain profiles. Each blend is made from food-grade, plant-derived terpenes.
How Is Guaiol Used?
Guaiol is used mainly as a fragrance ingredient. Its woody, rose-like scent evaporates slowly, so it works as a base note that lingers after lighter notes fade. The International Fragrance Association (IFRA) allows it in fragrance concentrates at up to 5%.
Guaiac wood oil and cypress pine oil, both rich in guaiol, appear in perfumes, soaps, candles, topical creams, and other natural products. In aromatherapy, these oils are usually diffused into the air or mixed with a carrier oil such as jojoba or coconut oil before being applied to the skin.
Guaiol is not approved as a food flavoring, so it should not be added to food or drinks. People also encounter it when they smoke or vaporize cannabis strains that contain it.
Outside fragrance, guaiol is a candidate for further anti-inflammatory and anticancer research, but it is not an approved drug ingredient. Chemists can also identify it in plant oils because it turns deep purple when treated with certain bromine reagents.
Some essential oils can irritate the skin or interact with medications. Talk to a healthcare professional before using any essential oil or terpene for a health purpose, especially if you have a medical condition or take medication.
Potential Side Effects of Guaiol
As with other concentrated plant extracts, guaiol and guaiol-rich oils can irritate sensitive skin. Always dilute them in a carrier oil and test a small area before wider use.
Breathing in high concentrations of any essential oil can irritate the nose, throat, and lungs. Use diffusers in well-ventilated rooms and keep concentrated oils away from children and pets.
There is very little safety data on guaiol taken by mouth. Do not ingest guaiol or guaiol-rich essential oils.
What We Know About Guaiol So Far
Some researchers think guaiol may add to the entourage effect, the idea that cannabinoids and other terpenes work together. No study has yet measured guaiol's own role in that effect.
Guaiol is a slow-evaporating, woody terpene with a small but growing body of lab research. The early findings on inflammation, bacteria, and cancer cells are worth following, but they do not yet show benefits in people.
If you enjoy woody and earthy cannabis aromas, guaiol is one of the compounds behind them. True Blue terpenes are food-grade and contain no THC, so you can explore strain flavors through our flavor blends, terpene-infused products, or a sample pack of any 5 strains.
Editor's note: This article is for general education and is not medical advice. Talk to a healthcare provider before using terpenes or essential oils for a health condition.