(2E,6E)-Farnesol is the all-trans farnesol isomer, a floral sesquiterpene alcohol used in fragrance and found in sandalwood-like and floral aromatic materials. The live evidence base is strongest for identity, fragrance-safety context, and microbiology research showing quorum-sensing and biofilm effects in Candida models. That makes it a well-supported chemistry and safety constituent, but its benefit-style evidence still remains largely preclinical rather than clinical.
Chemical identity and composition
PubChem resolves the all-trans isomer as CID 445070 for the broader farnesol record and lists the specific all-trans naming under the (2E,6E)-farnesol substance identity, while the IFRA Farnesol standard explicitly scopes multiple farnesol isomer CAS numbers including 4602-84-0, 106-28-5, 3790-71-4, 16106-95-9, and 3879-60-5. In the local archive this exact constituent ID is a major marker of Australian sandalwood, where the cited GC/MS report places (2E,6E)-farnesol at 24.7% of the oil profile.
Aroma and practical use
- Use the recorded floral, delicate, green, sweet descriptors to explore a blend's scent character; perceived strength also depends on the other ingredients.
- Review the flagged use concerns across every contributing oil and the selected dilution.
- Read the route, preparation and experimental context before using a study finding to choose an oil.
Reported benefits and effects
Findings retain their study context. An animal or laboratory result describes that experiment.
A 2001 Applied and Environmental Microbiology study identified farnesol as the extracellular Candida albicans quorum-sensing molecule and reported roughly 50% germ-tube inhibition around 30 to 35 microM.
A 2001 Applied and Environmental Microbiology study identified farnesol as the extracellular Candida albicans quorum-sensing molecule and reported roughly 50% germ-tube inhibition around 30 to 35 microM.
This experimental finding does not establish benefit, dose or safety in people using this blend.
A 2002 Applied and Environmental Microbiology study found that 300 microM farnesol completely inhibited Candida albicans biofilm formation in its tested early-adherence model and reduced HWP1 expression in treated biofilms.
A 2002 Applied and Environmental Microbiology study found that 300 microM farnesol completely inhibited Candida albicans biofilm formation in its tested early-adherence model and reduced HWP1 expression in treated biofilms.
This experimental finding does not establish benefit, dose or safety in people using this blend.
The 2023 RIFM fragrance safety assessment provides modern formal safety review coverage for farnesol in fragrance-use contexts rather than wellness efficacy contexts.
The 2023 RIFM fragrance safety assessment provides modern formal safety review coverage for farnesol in fragrance-use contexts rather than wellness efficacy contexts.
The source assessment applies to its specified exposure and preparation; this entry is not an unrestricted-use clearance.
Use concerns and concentration limits
Sensitization concernFlagged
Flagged in the constituent reference; assess the source, route and finished-product concentration.
Phototoxicity concernNot flagged
Not flagged in the current model. This is not proof of absence or unrestricted safety.
Oxidation concernNot assessed
Not assessed in the available record.
Penetration enhancementNot assessed
Not assessed in the available record.
A recorded constituent reference, not a recommended oil dilution. Product category, source applicability and all contributing oils must be checked before use.
recorded reference · IFRA Standard, Farnesol (Amendment 49, 2020) - Category 5A (leave-on skin) maximum acceptable concentration in finished product, 0.29%; in-scope CAS includes 106-28-5 ((2E,6E)-farnesol); basis: dermal sensitizationThe public IFRA Farnesol standard lists dermal sensitization as the risk basis and sets a Category 5A finished-product maximum of 0.29%, while also requiring a minimum fragrance-ingredient purity of 96% farnesol isomers.
The source assessment applies to its specified exposure and preparation; this entry is not an unrestricted-use clearance.
No direct public citation is attached to this entry.
A clinical review describes farnesol as an infrequent but important allergic contact dermatitis concern and concludes that the predictive and clinical literature does not show it to be a frequent contact allergen.
This reference does not establish a therapeutic result or a safe use level for a custom oil blend.
No direct public citation is attached to this entry.
Constituents it may interact with
No constituent-pair interaction is recorded for this identity. The report does not assume either amplification or incompatibility.
How the effects were investigated
candida morphogenesis control
In Candida albicans, farnesol acts extracellularly as a quorum-sensing signal that prevents yeast-to-mycelium conversion without stopping overall cell growth in the classic model.
This experimental finding does not establish benefit, dose or safety in people using this blend.
No direct public citation is attached to this entry.
biofilm formation suppression
In adherent Candida populations, higher farnesol exposure reduced biofilm formation and lowered expression of a hypha-associated wall-protein marker in the reported model.
This experimental finding does not establish benefit, dose or safety in people using this blend.
No direct public citation is attached to this entry.
What this report cannot establish
- A reported constituent percentage does not establish an effective human therapeutic dose or the amount absorbed into the body.
- The presence of a constituent does not guarantee a clinical benefit, rash treatment or sleep improvement from a custom blend.
- An unflagged concern or missing use limit does not establish safety for ingestion, inhalation, skin exposure or a particular person.
- A candidate constituent interaction does not establish that two oils amplify one another at the selected proportions.
- Constituent descriptors alone do not establish a precise top, heart or base lifetime in a finished blend.
Known data gaps (4)
- Public activity literature usually discusses farnesol broadly rather than separating every geometric isomer with clean comparative pharmacology.
- A stronger human efficacy dataset for isolated all-trans farnesol was not verified in this pass.
- Archive naming overlaps with other farnesol records, so identity should be read as the all-trans isomer within a broader farnesol family context.
- Some findings do not record an explicit exposure route; consult the linked study before applying them to a use.