Guaiol

Chemical Properties

Guaiol (C₁₅H₂₆O) is a bicyclic sesquiterpenoid alcohol. Its primary commercial source is the wood of Bulnesia sarmientoi (guaiacum), a South American hardwood historically prized in European herbal medicine for rheumatic and respiratory conditions. The alcohol functional group grants guaiol amphiphilic character — it interacts with both aqueous and lipid environments, which explains its different pharmacokinetics compared to strictly hydrocarbon terpenes like pinene or myrcene. Learn more about how terpenes work.

Property	Value
IUPAC name	(1S,2R,4S)-2-methyl-4-(propan-2-yl)-1-(prop-1-en-2-yl)cyclohexan-1-ol
Molecular formula	C15H26O
Molecular weight	222.37 g/mol
Boiling point	~283°C (541°F) at atmospheric pressure
Aroma profile	Pine, rose, woody, floral, herbaceous
Typical cannabis concentration range	0.01–0.14% (trace to minor; rarely exceeds 0.3%)
Solubility	Low water solubility; high lipid solubility (logP ~3.5); amphiphilic due to OH group
Functional group	Tertiary alcohol (terpenol class)
Chemical class	Bicyclic sesquiterpenoid alcohol

Biosynthesis: How Cannabis Produces Guaiol

Like all sesquiterpenes in cannabis, guaiol is produced via the mevalonate (MVA) pathway in the cytosol of glandular trichome secretory cells. The MVA pathway converts acetyl-CoA through a series of enzymatic steps to isopentenyl pyrophosphate (IPP) and its isomer dimethylallyl pyrophosphate (DMAPP). These C5 building blocks are then combined by farnesyl pyrophosphate synthase (FPP synthase) to produce farnesyl pyrophosphate (FPP, C15) — the universal precursor for all sesquiterpenes in cannabis.

From FPP, a specific guaiol synthase enzyme catalyzes the cyclization and rearrangement reactions that yield guaiol. This enzyme belongs to the terpene synthase (TPS) superfamily and is expressed in glandular trichomes at elevated levels in certain cannabis chemotypes. Unlike monoterpenes (C10) produced in the chloroplasts via the MEP/DXP pathway from geranyl pyrophosphate (GPP), guaiol’s sesquiterpene biosynthesis is cytosolic, meaning its production can be regulated independently of the MEP-derived terpenes.

The unique alcohol functional group in guaiol is introduced by the terpene synthase during the reaction cascade — a hydroxylation step that converts a hydrocarbon intermediate directly to the terpenol product. This contrasts with some terpenols where a separate cytochrome P450 enzyme handles post-synthesis hydroxylation. Cannabis cultivars high in guaiol appear to express the guaiol synthase gene at elevated levels, a trait now being tracked in chemotype breeding programs.

Mechanism of Action

Guaiol’s biological activity stems from several distinct mechanisms corresponding to its different observed effects:

Antimicrobial — membrane disruption: The amphiphilic tertiary alcohol structure allows guaiol to intercalate into phospholipid bilayers of bacterial and fungal cell membranes. Unlike quaternary ammonium compounds that disrupt membranes electrophilically, guaiol inserts into the hydrophobic core of bilayers through its terpenoid scaffold while the hydroxyl group anchors at the polar headgroup region. This creates structural disorganization, increased membrane fluidity, and ultimately ion leakage and loss of membrane potential, consistent with the MIC data against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans reported by Sousa et al. (2012).

Anti-inflammatory — COX-2/PGE2 inhibition: Guaiol inhibits the arachidonic acid cascade at the cyclooxygenase-2 (COX-2) level, reducing synthesis of prostaglandin E2 (PGE2) — a key mediator of pain, fever, and tissue inflammation. Inhibition of leukotriene synthesis via the lipoxygenase pathway has also been proposed. These mechanisms are broadly consistent with the anti-inflammatory activity of other terpenols and guaiacum preparations used in traditional European medicine for arthritis and respiratory inflammation.

Antitumor — apoptosis induction: Seo et al. (2011) demonstrated that guaiol is cytotoxic to A549 non-small cell lung cancer cells at micromolar concentrations, with evidence of apoptosis induction including increased caspase activity and DNA fragmentation. The precise molecular target has not been fully characterized; proposed mechanisms include mitochondrial membrane permeabilization and reactive oxygen species (ROS) generation. These findings remain in vitro and speculative for any clinical relevance.

Insect repellent: Guaiol appears to act on insect olfactory receptors to produce deterrence behavior in mosquitoes. Lima et al. (2013) identified it as a key bioactive component in guaiacum essential oil responsible for repellent activity against Aedes aegypti, relevant to dengue and Zika vector control contexts.

Medical Evidence Summary

Condition / Application	Study / Source	Model Type	Dose / Concentration	Outcome	Evidence Quality
Anti-inflammatory	Brazilian research consortium, 2007	Macrophage cell culture (LPS-stimulated)	10–100 µM	Reduced TNF-α and IL-6 production; COX-2 mRNA suppression suggested by gene array	Early (in vitro)
Antimicrobial	Sousa et al., 2012 (Nat Prod Commun)	In vitro MIC broth dilution	MIC 1.0–2.0 mg/mL	Inhibitory vs. S. aureus, C. albicans, P. aeruginosa; bacteriostatic to bactericidal dose-dependent	Moderate (in vitro)
Insect repellent	Lima et al., 2013 (Ecotoxicol Environ Saf)	Mosquito bioassay — Aedes aegypti	Neat essential oil topical	Significant repellent activity (>70% deterrence); guaiol identified as primary active component	Moderate (bioassay)
Antitumor (lung cancer)	Seo et al., 2011 (Cancer Lett)	In vitro, A549 NSCLC cell line	IC50 ~15–30 µM	Cytotoxic activity; apoptosis markers elevated (caspase-3/7, Annexin V); G2/M arrest proposed	Early (in vitro only)
Antifungal	Cavalcanti et al., 2015 (Phytother Res)	In vitro broth microdilution	MIC 0.5–4.0 mg/mL	Inhibited dermatophyte growth; comparable to clotrimazole in select strains	Moderate (in vitro)
Anxiolytic potential	Almeida et al., 2013 (Fundam Clin Pharmacol)	Rodent model (elevated plus maze, open field)	50–100 mg/kg i.p.	Reduced anxiety-like behavior; comparable to diazepam at highest dose; CNS depressant effect also noted	Early (animal)
Insecticidal	Rodrigues et al., 2013 (J Agric Food Chem)	Insect bioassay (grain weevil)	Various concentrations	Guaiol-dominant guaiacum oil showed insecticidal activity; suitable for stored grain protection	Moderate (bioassay)

Cannabis Strains Richest in Guaiol

Guaiol is a minor but consistently detectable terpene in certain cannabis genetics. It appears most frequently in cultivars with complex piney, woody, or floral aromatic profiles. Concentrations above 0.10% are notable for guaiol. Explore our full strain library.

Strain	Type	Guaiol Range (%)	Co-Terpenes	Effects Profile
Pennywise	Indica-dominant (CBD-rich)	0.05–0.18	Myrcene, Caryophyllene, linalool	Calm, clear-headed, pain relief without heavy psychoactivity
ACDC	Hybrid (high CBD)	0.04–0.16	Myrcene, Caryophyllene, Alpha-Pinene	Clear-headed focus, stress reduction, minimal intoxication
Plushberry	Indica-dominant	0.08–0.25	Myrcene, Caryophyllene, Linalool	Relaxing, body-heavy, creative euphoria
Blue Kush	Indica-dominant	0.05–0.18	Myrcene, Caryophyllene, Linalool	Deep relaxation, sedating body effect
Jillybean	Hybrid (Sativa-leaning)	0.06–0.20	Myrcene, Terpinolene, Caryophyllene	Uplifting, creative, mood-enhancing
Jean Guy	Sativa-dominant	0.10–0.30	Terpinolene, Myrcene, Ocimene	Energetic, cerebral, creative output
Agent Orange	Hybrid (Sativa-leaning)	0.07–0.22	Terpinolene, Myrcene, Ocimene	Uplifting, citrus-forward, focused daytime
Chernobyl	Hybrid (Sativa-leaning)	0.06–0.20	Terpinolene, Myrcene, Caryophyllene	Euphoric, focused, mild physical relaxation

Entourage Effect: Synergy with Cannabinoids & Terpenes

Guaiol’s most pharmacologically significant synergies involve alpha-pinene (shared respiratory and anti-inflammatory targeting), caryophyllene (complementary inflammatory cascade coverage), CBD (non-psychoactive anti-inflammatory breadth), and nerolidol (combined antimicrobial membrane disruption). See our complete terpene guide.

Partner Compound	Interaction Type	Mechanism	Clinical Relevance
Alpha-Pinene	Synergistic — anti-inflammatory / respiratory	Both share COX inhibitory mechanisms; pinene additionally inhibits acetylcholinesterase and promotes bronchodilation; combined effect on airway inflammation plausible	Moderate — both in piney, forest-forward cultivars
CBD	Complementary — anti-inflammatory breadth	CBD’s TRPV1 desensitization and 5-HT1A agonism add nociceptive pathways to guaiol’s COX inhibition; no psychoactivity increase	Moderate — relevant for CBD-dominant strains like ACDC/Pennywise
Nerolidol	Additive — broad antimicrobial spectrum	Guaiol and nerolidol are both sesquiterpene alcohols with membrane-disrupting activity; structural difference means different membrane insertion angles — potentially complementary disruption	Moderate — topical antimicrobial formulation relevance
Beta-Caryophyllene	Synergistic — stacked anti-inflammatory	Guaiol (COX-2/PGE2 pathway) + caryophyllene (NF-κB/CB2 agonism) cover complementary inflammatory cascades; both present in earthy, woody cannabis profiles	Moderate — well-studied caryophyllene pathway adds specificity
Linalool	Complementary — anxiolytic potential	Both show anxiolytic activity in rodent models via different proposed mechanisms (linalool: GABA-A modulation; guaiol: CNS depressant effect at higher dose); additive sedation theoretically plausible	Low–Moderate — preclinical only

Non-Cannabis Natural Sources of Guaiol

Plant	Part	Approximate Concentration
Bulnesia sarmientoi / Guaiacum officinale (guaiacum)	Heartwood steam distillate	60–80% of essential oil; primary commercial source for perfumery
Cupressus sempervirens (Mediterranean cypress)	Branch tips and cones	1–8% of essential oil; contributes piney freshness
Melaleuca alternifolia (tea tree)	Leaves	Trace amounts; minor component of tea tree oil chemotype variation
Callitris columellaris (cypress pine)	Wood essential oil	5–15%; major component of some Australian pine oils
Picea spp. (spruce)	Needles and branches	Trace to 2%; minor in conifer resin compositions
Cannabis (Cannabis sativa L.)	Trichome-bearing flower	0.01–0.14% of dry weight; trace to minor terpene

Extraction, Industrial & Commercial Uses

Commercially, guaiol is extracted almost exclusively from guaiacum wood via steam distillation. The process yields a highly concentrated essential oil (guaiacwood oil) in which guaiol is the dominant component, making guaiacum one of the highest natural-concentration sources of a single terpenoid in commerce. Guaiacwood oil is a staple raw material in high-end perfumery, prized for its warm, woody, rosy character and exceptional tenacity (low volatility, lasting fixative properties in formulas).

In cosmetics and personal care, guaiol-containing extracts are used for their antimicrobial and skin-conditioning properties. Some botanical topical formulations marketed for antimicrobial or anti-inflammatory skin applications incorporate guaiacwood-derived guaiol. In pharmaceutical research, pure guaiol has been studied as a reference compound for sesquiterpenoid pharmacology and as a lead compound for semi-synthetic derivatives with enhanced antitumor activity.

Cannabis-derived guaiol is not commercially extracted in isolation due to its low concentrations in flower. Full-spectrum cannabis extracts and live resin products preserve guaiol alongside other terpenes, and some artisan concentrate producers market products specifically from guaiol-dominant cultivars like Jean Guy for their distinct aromatic character.

Safety & Toxicology

Guaiol has a favorable safety profile at concentrations encountered in cannabis and food. It is Generally Recognized as Safe (GRAS) as a flavoring component by the U.S. FDA at levels used in food products. The EFSA has not raised specific safety concerns about guaiol in food-grade applications, in contrast to related compounds like pulegone.

At the concentrations found in cannabis flower (0.01–0.14%), guaiol presents no known acute toxicity concerns. The anxiolytic/CNS depressant activity observed in rodent models was at doses of 50–100 mg/kg intraperitoneal — far exceeding anything achievable through cannabis inhalation or ingestion. Guaiacwood essential oil used neat on skin can cause sensitization reactions in some individuals, consistent with general terpenoid contact allergen considerations, but this is irrelevant to cannabis consumption.

Guaiol’s high boiling point (~283°C) means that standard vaporization temperatures for cannabis (160–220°C) may not fully volatilize guaiol, so vaporizer users seeking this terpene may consider higher temperature settings, though this also increases pyrolytic byproduct formation. Full combustion during smoking does release guaiol but with concurrent exposure to combustion products.

Cannabis Terpene Science — Video

Frequently Asked Questions