CONSTITUENT REPORT
1,8-cineole
1,8-cineole, also called eucalyptol, is a fresh camphoraceous monoterpene oxide best known as a major aromatic marker in eucalyptus, rosemary cineole chemotypes, ravintsara, niaouli, cajeput, and related oils. Public human research is stronger here than for many aroma constituents: clinical studies and mechanism papers consistently connect 1,8-cineole with airway-focused, anti-inflammatory, and mucus-thinning activity, while safety sources still support conservative use around young children and dose-aware handling because concentrated cineole-rich materials can irritate or stress sensitive users.
Chemical identity and composition
1,8-cineole is the common cineole isomer used as an identity marker for many cineole-rich essential oils. It is a bicyclic ether with the formula C10H18O and is routinely treated in the literature as both an odor-active constituent and a pharmacologically active monoterpene oxide.
Aroma and practical use
- Use the recorded fresh, camphoraceous, eucalyptus-like, cooling, penetrating, medicinal descriptors to explore a blend's scent character; perceived strength also depends on the other ingredients.
- Compare the recorded goal signals with the intended purpose, while keeping model assumptions separate from observed study outcomes.
- 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 placebo-controlled asthma trial reported a steroid-sparing signal with oral 1,8-cineole in steroid-dependent patients.
Europe PMC's abstract summary reports 32 patients in a double-blind placebo-controlled trial and describes anti-inflammatory efficacy assessed against prednisolone-equivalent need.
Apply this finding only to the studied preparation, participants, route and outcome. It does not establish the same result for a custom oil blend.
A randomized placebo-controlled rhinosinusitis study reported symptom improvement with cineole capsules.
Search-accessible indexing states the trial enrolled 152 acute nonpurulent rhinosinusitis patients and compared cineole against placebo.
Apply this finding only to the studied preparation, participants, route and outcome. It does not establish the same result for a custom oil blend.
Mouse toxicology work found a relatively high acute oral LD50 but dose-related liver and kidney changes at higher repeated doses.
The abstract reports an acute oral LD50 of 3849 mg/kg in mice and notes histopathologic liver and kidney changes at higher subacute doses.
This experimental finding does not establish benefit, dose or safety in people using this blend.
How it contributes to goal calculations
Model markers guide the formulation score. They are separate from the source findings above.
Use concerns and concentration limits
Sensitization concernNot flagged
Not flagged in the current model. This is not proof of absence or unrestricted safety.
Phototoxicity concernNot flagged
Not flagged in the current model. This is not proof of absence or unrestricted safety.
Oxidation concernNot flagged
Not flagged in the current model. This is not proof of absence or unrestricted safety.
Penetration enhancementFlagged
Flagged in the constituent reference; assess the source, route and finished-product concentration.
A recorded constituent reference, not a recommended oil dilution. Product category, source applicability and all contributing oils must be checked before use.
recorded reference · Tisserand & Young, Essential Oil Safety 2nd ed. - eucalyptus/cineole-rich oil monograph maximum dermal use level 20%; no IFRA Standard restriction for 1,8-cineole itself was located in this passConcentrated 1,8-cineole is best treated as a high-aroma active constituent rather than a gentle background terpene.
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.
Cineole-rich oils are commonly handled cautiously around infants and young children because strong cineole exposure near the face can provoke breathing problems in susceptible children.
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.
Animal toxicology suggests a wide margin before acute lethality, but repeated higher-dose exposure still produced organ-level changes, so absence of low-dose acute toxicity should not be read as unrestricted safety.
This experimental finding does not establish benefit, dose or safety in people using this blend.
No direct public citation is attached to this entry.
Constituents it may interact with
These are research candidates recorded in the interaction matrix. They do not add a proven-amplification bonus to the score.
alpha-PineneAmplification candidate
Candidate in the research matrix. A coefficient alone does not establish amplification at the dose, route or goal of your blend; no proven amplification is inferred from this row.
in vitro · effect
No source citation attached.
Read alpha-Pinene report →LimoneneOpposing candidate
Candidate in the research matrix. A coefficient alone does not establish amplification at the dose, route or goal of your blend; no proven amplification is inferred from this row.
in vitro · effect
No source citation attached.
Read Limonene report →alpha-TerpineolOpposing candidate
Candidate in the research matrix. A coefficient alone does not establish amplification at the dose, route or goal of your blend; no proven amplification is inferred from this row.
animal · effect
No source citation attached.
Read alpha-Terpineol report →Terpinen-4-olAmplification candidate
Candidate in the research matrix. A coefficient alone does not establish amplification at the dose, route or goal of your blend; no proven amplification is inferred from this row.
in vitro · effect
No source citation attached.
Read Terpinen-4-ol report →CarvacrolAmplification candidate
Candidate in the research matrix. A coefficient alone does not establish amplification at the dose, route or goal of your blend; no proven amplification is inferred from this row.
in vitro · effect
No source citation attached.
Read Carvacrol report →beta-PineneAmplification candidate
Candidate in the research matrix. A coefficient alone does not establish amplification at the dose, route or goal of your blend; no proven amplification is inferred from this row.
in vitro · effect
No source citation attached.
Read beta-Pinene report →AromadendreneAmplification candidate
Candidate in the research matrix. A coefficient alone does not establish amplification at the dose, route or goal of your blend; no proven amplification is inferred from this row.
in vitro · effect
No source citation attached.
Read Aromadendrene report →CamphorAmplification candidate
Candidate in the research matrix. A coefficient alone does not establish amplification at the dose, route or goal of your blend; no proven amplification is inferred from this row.
in vitro · effect
No source citation attached.
Read Camphor report →alpha-PineneAmplification candidate
Candidate in the research matrix. A coefficient alone does not establish amplification at the dose, route or goal of your blend; no proven amplification is inferred from this row.
in vitro · antioxidant
No source citation attached.
Read alpha-Pinene report →CarvacrolAmplification candidate
Candidate in the research matrix. A coefficient alone does not establish amplification at the dose, route or goal of your blend; no proven amplification is inferred from this row.
in vitro · whole_oil
No source citation attached.
Read Carvacrol report →alpha-TerpineolAmplification candidate
Candidate in the research matrix. A coefficient alone does not establish amplification at the dose, route or goal of your blend; no proven amplification is inferred from this row.
in vitro · whole_oil
No source citation attached.
Read alpha-Terpineol report →LinaloolAmplification candidate
Candidate in the research matrix. A coefficient alone does not establish amplification at the dose, route or goal of your blend; no proven amplification is inferred from this row.
in vitro · effect
No source citation attached.
Read Linalool report →CamphorAmplification candidate
Candidate in the research matrix. A coefficient alone does not establish amplification at the dose, route or goal of your blend; no proven amplification is inferred from this row.
animal · effect
No source citation attached.
Read Camphor report →(E)-CaryophylleneAmplification candidate
Candidate in the research matrix. A coefficient alone does not establish amplification at the dose, route or goal of your blend; no proven amplification is inferred from this row.
animal · effect
No source citation attached.
Read (E)-Caryophyllene report →alpha-TerpineneAmplification candidate
Candidate in the research matrix. A coefficient alone does not establish amplification at the dose, route or goal of your blend; no proven amplification is inferred from this row.
in vitro mechanistic · antioxidant
No source citation attached.
Read alpha-Terpinene report →MentholAmplification candidate
Candidate in the research matrix. A coefficient alone does not establish amplification at the dose, route or goal of your blend; no proven amplification is inferred from this row.
clinical · whole_oil
No source citation attached.
Read Menthol report →How the effects were investigated
suppression of pro-inflammatory cytokine signaling
Reviewed mechanism literature consistently describes lower TNF-alpha, IL-1 beta, IL-6, IL-8, leukotriene, and prostaglandin signaling after 1,8-cineole exposure in inflammatory models.
This reference does not establish a therapeutic result or a safe use level for a custom oil blend.
TRPM8 agonism with antagonism of human TRPA1
Open-access channel work reports that 1,8-cineole activates TRPM8 and inhibits human TRPA1, a plausible route for cooling sensation and some irritation-modulating effects.
This experimental finding does not establish benefit, dose or safety in people using this blend.
mucolytic and airway-secretion modulation
Clinical and review literature repeatedly frame cineole as a secretion-thinning and airway-comfort constituent rather than a general-purpose systemic agent.
Apply this finding only to the studied preparation, participants, route and outcome. It does not establish the same result for a custom oil blend.
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 (5)
- This pass did not verify a pregnancy-specific safety monograph for isolated 1,8-cineole.
- Several mechanistic statements in the literature are review-level syntheses rather than one single definitive target-validation paper.
- Most accessible child-safety cautions are published at the cineole-rich oil level rather than as purified 1,8-cineole exposure standards.
- Some findings do not record an explicit exposure route; consult the linked study before applying them to a use.
- Interaction candidates lack an attached source citation and remain unqualified.