Alpha-Isomethyl Ionone

AKA: 3-Methyl-4-(2, 6, 6-trimethyl-2-cyclohexen-1-yl)-3-buten-2-one, (3E)-3-methyl-4-(2, 6-trimethylcyclohex-2-en-1-yl)but-3-en-2-one, Alpha-isomethylionone, 127-51-5, Cetone alpha, Alpha-iso-Methylionone, Isomethyl-alpha-ionone, Isonaline 70
Allergen Warning
⚠️ EU Fragrance Allergen
Synthetic
Fragrance
Skin Conditioner
Not Clean
3-Methyl-4-(2,6,6-trimethyl-2-cyclohexenyl)-3-buten-2-one; Methyl-gamma-ionone; gamma-Methylionone
Formula
C14H22O
Mol. Weight
206.32
CAS #
127-51-5
Form
Oil
State
Dry Powder, Liquid, Other Solid; Liquid
Functions
Perfuming
Added for scent. Can be natural or synthetic. Common irritant and allergen — one of the top reasons people react to products.
Skin Conditioning
A catch-all term for ingredients that improve how skin looks and feels — softer, smoother, more supple. The workhorse behind most moisturizers.
Traditional Use
A synthetic fragrance compound developed in the 20th century as part of the modern perfumery industry's expansion. Designed to mimic woody and floral notes, it has no traditional or historical use but became standard in cosmetic fragrances from the 1960s onward.
EWG
3
CIR
Safe w/Qualifications
Pregnancy
Caution
Regulatory Status
USApermitted
EUpermitted
JAPANpermitted
CANADApermitted
Best For
General
Pregnancy & Breastfeeding Safe
Caution
The paper trail
🔬Peer-reviewed1 paper
⚖️Regulatory1 listing
🛡️Safety-assessed1 review
Counts, not a verdict. A listing isn't a study. The trail, you decide.
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR