Alpha-Isomethyl Ionone
INCI: ALPHA-ISOMETHYL IONONE
Also known as: Alpha-isomethyl Ionone
A synthetic fragrance ingredient that adds scent and conditioning properties to skincare formulations
At a glance
Things to be aware of
Best For Skin Types
All
Usage Frequency
As part of formulated products; follow product instructions
What Is Alpha-Isomethyl Ionone?
Alpha-isomethyl ionone is a synthetic fragrance compound commonly used in cosmetics and personal care products. It belongs to a class of aromatic chemicals designed to provide pleasant scent whilst also offering mild skin conditioning benefits.
This ingredient appears in roughly 3.3% of skincare products on the market, typically in small concentrations as part of fragrance blends rather than as a standalone active component.
How It Works
Alpha-isomethyl ionone functions primarily as a volatile aromatic compound that evaporates from the skin surface, delivering fragrance notes. The conditioning aspect works through basic emollient action, helping to coat the skin and reduce transepidermal water loss.
As a synthetic molecule, it is designed to be stable and consistent across formulations, though research indicates some fragrance components in this category can degrade when exposed to light or air, potentially forming reactive byproducts.
Clinical Evidence & References
Alpha-isomethyl ionone is recognised as a potential skin sensitiser, and allergic contact dermatitis has been associated with exposure to this ingredient. Research indicates it is one of several fragrance compounds of concern for skin sensitization risk assessment.
The ingredient has been included in quantitative risk assessments for fragrance allergens, particularly in leave-on products applied to sensitive skin areas. However, individual sensitivity varies considerably, and most people using products containing this ingredient at typical concentrations do not experience adverse effects.
How to Use
If your skin is sensitive or prone to irritation, check product labels and patch test before use. Those with a known fragrance allergy should avoid products listing this ingredient. For general use, application frequency depends on the specific product — follow the manufacturer's guidance for your chosen formulation.
Safety & Precautions
How widely it's used
Regulatory information
Standardised cosmetic-ingredient identifiers used by regulators.
Show identifiers
- INCI Name
- ALPHA-ISOMETHYL IONONE
- EC Number
- 204-846-3
- Function
- Perfuming, Skin Conditioning
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