Germacrene D is a common woody-spicy sesquiterpene hydrocarbon found across many essential oils in the AromaForge archive, including ylang ylang fractions and clary sage. The public evidence base is materially stronger here than for many trace sesquiterpenes: identity data are solid, biosynthetic and rearrangement chemistry are well documented, and a recent fragrance-safety assessment exists. Biological activity reports are still mostly ecological or whole-oil studies rather than definitive isolated human evidence, so AromaForge should frame germacrene D primarily as a chemistry and aroma marker with cautious mixture-level context.
Chemical identity and composition
PubChem lists germacrene D as C15H24 with InChIKey GAIBLDCXCZKKJE-RXJOXMPGSA-N and the IUPAC name (1E,6E,8S)-1-methyl-5-methylidene-8-propan-2-ylcyclodeca-1,6-diene. The literature repeatedly treats it as a key sesquiterpene precursor and notes distinct enantiomeric forms. In the local archive it appears prominently in ylang ylang extra at 14.58%, ylang ylang III at 17.64%, and clary sage at a mean 4.12%.
Aroma and practical use
- Use the recorded woody, spicy, green, herbal, herbaceous descriptors to explore a blend's scent character; perceived strength also depends on the other ingredients.
- 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 2000 Phytochemistry study investigated germacrene D rearrangements and described it as a precursor for multiple sesquiterpene hydrocarbon classes.
A 2000 Phytochemistry study investigated germacrene D rearrangements and described it as a precursor for multiple sesquiterpene hydrocarbon classes.
This reference does not establish a therapeutic result or a safe use level for a custom oil blend.
A 2018 Journal of Organic Chemistry paper reported two different enantioselective synthases in Solidago canadensis that biosynthesize (+)- and (-)-germacrene D.
A 2018 Journal of Organic Chemistry paper reported two different enantioselective synthases in Solidago canadensis that biosynthesize (+)- and (-)-germacrene D.
This reference does not establish a therapeutic result or a safe use level for a custom oil blend.
A 2024 Food and Chemical Toxicology citation confirms germacrene D received a dedicated RIFM fragrance ingredient safety assessment.
A 2024 Food and Chemical Toxicology citation confirms germacrene D received a dedicated RIFM fragrance ingredient safety assessment.
The source assessment applies to its specified exposure and preparation; this entry is not an unrestricted-use clearance.
A 2023 pyrethrum-flower paper reported nocturnal burst emissions of germacrene D that induced moth oviposition on a nonhost and improved pollination success, reinforcing its ecological signaling role.
A 2023 pyrethrum-flower paper reported nocturnal burst emissions of germacrene D that induced moth oviposition on a nonhost and improved pollination success, reinforcing its ecological signaling role.
This experimental finding does not establish benefit, dose or safety in people using this blend.
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 enhancementNot flagged
Not flagged in the current model. This is not proof of absence or unrestricted safety.
No numeric constituent-specific use limit is available here. Missing is not an unrestricted-use clearance.
A dedicated 2024 RIFM fragrance ingredient safety assessment exists for germacrene D, supporting a cautious fragrance-safety framing even though the full toxicology details were not fully accessible in this pass.
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.
The reviewed accessible literature did not provide robust human efficacy trials for isolated germacrene D.
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
rearrangement precursor to multiple sesquiterpene scaffolds
A classic Phytochemistry paper investigated acid-catalyzed, photochemical, and thermal rearrangements of germacrene D and supported its role as a precursor to cadinane, eudesmane, oppositane, axane, isodaucane, and bourbonane sesquiterpene groups.
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.
enantioselective synthase formation
Solidago canadensis research showed that separate enantioselective sesquiterpene synthases can produce (+)- and (-)-germacrene D, clarifying how plants generate its enantiomer-specific profiles.
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.
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 (6)
- No high-quality human efficacy studies specific to isolated germacrene D were verified in the reviewed public sources.
- Many reported biological effects are ecological or whole-oil findings rather than direct constituent-dose human data.
- 2026-07-13 verification pass: retrieved the full-text 2024 RIFM safety assessment (Food Chem Toxicol 183:114542). It concludes germacrene D is 'not a concern for skin sensitization under the current declared levels of use' (based on read-across to beta-caryophyllene/myrcene) and 'not expected to be photoirritating/photoallergenic' (based on UV/Vis spectra below the 1000 L mol-1 cm-1 benchmark). No explicit numeric dermal-limit percentage or IFRA restriction is stated in the assessment (repeated-dose/reproductive/local-respiratory endpoints were TTC-based, not dermal-limit-based), so dermal_limit_pct remains null/unverified; sensitizing and phototoxic are corrected from unsourced placeholders to verified values from this citation.
- 2026-07-13 second-pass retry: searched the IFRA 51st Amendment complete standards compilation and press materials specifically for a germacrene D (CAS 23986-74-5) restriction Standard; found only general amendment summary information (59 new rules covering skin sensitization/systemic toxicity categories) with no germacrene D-specific entry surfaced, consistent with the RIFM assessment's TTC-based (not dermal-limit-based) framing already on file. No penetration_enhancer data were located in any pass to date. dermal_limit_pct and penetration_enhancer remain null/unverified.
- No constituent-specific numeric dermal reference is available here.
- Some findings do not record an explicit exposure route; consult the linked study before applying them to a use.