Guaiol (Sesquiterpene Alcohol · Anti-inflammatory · Antimicrobial · Insect Repellent)

Compound	Guaiol
Chemical class	Terpenoid — Sesquiterpene Alcohol (Guaiane skeleton)
CAS	489-86-1
Primary source	Guaiacum officinale (lignum vitae), Psidium guajava (guava), Bulnesia sarmientoi (palo santo)
Key applications	Anti-inflammatory, antimicrobial, insect repellent, fragrance active
Claim strength	Moderate
Typical form	Guaiacwood essential oil constituent (guaiol 40–65%); guava extract co-constituent
Buy from Herbuno	Request availability and bulk pricing →

Name origin: From Guaiacum (lignum vitae tree), the primary traditional source. Guaiol is a bicyclic sesquiterpene alcohol with the guaiane carbon skeleton, best known as the primary constituent of guaiacwood essential oil (Guaiacum officinale and Bulnesia sarmientoi). Traditional use: Guaiacum wood and resin have been used in European and Caribbean traditional medicine since the 16th century — introduced to Europe from the Americas as a treatment for syphilis and rheumatic conditions. Psidium guajava (guava) leaves and bark containing guaiol have extensive traditional use across tropical Asia, Africa, and Latin America for diarrhoea, wound healing, coughs, and skin conditions. Research trajectory: Guaiol has documented anti-inflammatory (NF-κB inhibition), antimicrobial (activity against S. aureus, E. coli, and Candida), and insect-repellent properties in preclinical research. An interesting emerging mechanism is apoptosis induction in lung cancer cell lines (mitochondrial pathway), though this is early-stage research. Commercial source: Not currently available as a standalone extract at commercial supplement scale from Herbuno. Contact Herbuno for availability assessment.

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Evidence for Guaiol Applications

Anti-inflammatory: Guaiol inhibits NF-κB and reduces pro-inflammatory cytokine production in macrophage and epithelial models. Guaiacwood preparations have traditional anti-rheumatic use that correlates with preclinical anti-inflammatory mechanism data. Claim strength: Moderate (preclinical).

Antimicrobial: Guaiol demonstrates MIC values of 0.2–1 mg/mL against S. aureus, E. coli, Candida albicans, and food-borne pathogens. Guava leaf preparations containing guaiol have ethnobotanical and in vitro evidence for antimicrobial activity against GI pathogens (relevant to traditional diarrhoea use). Claim strength: Moderate.

Insect repellent: Guaiol demonstrates activity against mosquitoes (Aedes aegypti) and other insects in laboratory assays. Guaiacwood oil (guaiol-dominant) is used as a natural insect repellent and in anti-moth preparations. Claim strength: Moderate.

Antiproliferative (early-stage): Guaiol induces mitochondrial apoptosis in A549 lung cancer cells and reduces cell proliferation in other cancer cell lines. Mechanism involves Bcl-2 family modulation and reactive oxygen species generation. Claim strength: Emerging (cell line data only).

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Dosage & Formulator Specification

No established human supplement dose for guaiol. Traditional guaiacwood resin preparations for rheumatic conditions used gram-level doses of the crude resin, delivering guaiol as part of the complex mixture. Guava leaf extract at 400–800 mg/day (traditional dose for GI complaints) co-delivers guaiol alongside quercetin, kaempferol, and other guava polyphenols. Guaiacwood essential oil (40–65% guaiol) is used in fragrance applications at standard essential oil use concentrations. Contact Herbuno for guaiol extract availability and specification. IMPORTANT: Guaiacum officinale and Bulnesia sarmientoi are CITES-listed due to over-harvesting — verify sustainable sourcing and CITES compliance for any guaiacwood-derived material.

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Frequently Asked Questions — Guaiol

Is guaiol the same as guaiacol?
No. Guaiol is a sesquiterpene alcohol from guaiacwood (Guaiacum / Bulnesia). Guaiacol (2-methoxyphenol) is a phenolic compound from guaiac resin and also from wood smoke — a completely different chemical class with different pharmacological properties. The similar names reflect their common guaiac/guaiacum botanical origin but they are structurally and pharmacologically distinct.

Is guava leaf extract a source of guaiol for supplement applications?
Yes — Psidium guajava leaves contain guaiol as a sesquiterpene constituent of the essential oil fraction alongside other terpenoids and polyphenols (quercetin, kaempferol, guaijaverin). Guava leaf extract is commercially available and does not have the CITES sustainability concerns of guaiacwood. For supplement formulations seeking guaiol activity alongside broader guava phytochemical benefits, guava leaf extract is the more commercially appropriate and sustainable source.

Why are guaiacum species CITES-listed?
Guaiacum officinale and G. sanctum (lignum vitae) are listed on CITES Appendix II due to historical over-exploitation. Lignum vitae (“wood of life”) is one of the densest and hardest woods globally and was extensively harvested for industrial use (propeller shaft bearings, bowling balls, medicinal resin). Bulnesia sarmientoi (palo santo) is also CITES Appendix II. Any commercial use of guaiacwood-derived material requires CITES trade documentation and verification of legal harvest.

Can guaiol be used in a natural insect repellent product?
Yes — guaiacwood oil (dominant in guaiol) has demonstrated mosquito repellent activity and is used in natural insect repellent formulations as an alternative to citronellol and eucalyptus oil. For CITES-compliant formulations, guaiol should be sourced from Psidium guajava (guava) leaf essential oil or Bulnesia sarmientoi with verified sustainable harvesting certification rather than from CITES-listed guaiacum species.

Related compounds: Artabsin, Bisabolol, Patchouli Alcohol, Cedrene

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Claim-strength scale – High = multiple human RCTs; Moderate = limited trials or strong preclinical convergence; Emerging = early-stage lab or animal data.

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