Ingredient review
Hexahydro-Tetramethyl-Methanoazulen-5-One
INCI: HEXAHYDRO-TETRAMETHYL-METHANOAZULEN-5-ONE
A synthetic fragrance ingredient that adds a warm, woody scent but offers no skincare benefits and may be unnecessary for sensitive skin.
In plain English
This is a lab-made chemical that smells like wood or amber. It is added to products to make them smell nice, but it doesn't moisturize, protect, or improve your skin. If you have sensitive skin or prefer fragrance-free products, you might want to avoid it.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Hexahydro-Tetramethyl-Methanoazulen-5-One is generally a lower-concern ingredient when the full formula suits your skin.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging Hexahydro-Tetramethyl-Methanoazulen-5-One.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
A synthetic organic compound from the azulene family, created in a lab to produce a specific woody, amber-like fragrance note. It is not derived from natural sources.
How it works
It works by binding to scent receptors in the nose, creating the perception of a warm, woody aroma. In a product, it simply adds fragrance and does not actively affect the skin's structure or function.
Pros
Pleasant scent
Adds a warm, woody fragrance that many find appealing and can make a product feel more luxurious.
Low concentration needed
Only a tiny amount is required to achieve the desired scent, so it is unlikely to cause issues for most people.
Cons and cautions
No skin benefit
This ingredient only provides fragrance and does not hydrate, soothe, or protect the skin in any way.
Potential allergen
As a synthetic fragrance, it can trigger allergic reactions or irritation in people with sensitive skin or fragrance sensitivities.
Best for
- People who enjoy woody, amber-like fragrances in their skincare
- Those without fragrance sensitivities
Use caution if
- Individuals with sensitive skin, eczema, or known fragrance allergies
Usage tips
Safety summary
Generally considered safe for most people at the low concentrations used in cosmetics. However, it can cause skin irritation or allergic reactions in sensitive individuals, as with many fragrance ingredients.
Research notes
There is limited published research specifically on this compound. Its safety is inferred from general fragrance ingredient safety assessments, which note that skin sensitization is possible but uncommon at typical use levels.
Common label clues
- Typical concentration
- Typically used at very low concentrations (less than 1%) due to its strong scent.
- Regulatory status
- Approved for use in cosmetics in the US and EU, but must be listed on the ingredient label as a fragrance component.
- Common uses
- Fragranced skincare, Perfumes, Body lotions, Hair products
- Environmental note
- As a synthetic compound, its environmental persistence and impact are not well-studied, but it is used in very low concentrations.
Good to know
- This ingredient is often listed near the end of an ingredient list, indicating it is used in very small amounts.
- Fragrance ingredients are not required to be individually disclosed on labels, so this may be part of a proprietary fragrance blend.
Common questions
What is Hexahydro-Tetramethyl-Methanoazulen-5-One in beauty products?
This is a lab-made chemical that smells like wood or amber. It is added to products to make them smell nice, but it doesn't moisturize, protect, or improve your skin. If you have sensitive skin or prefer fragrance-free products, you might want to avoid it.
What does Hexahydro-Tetramethyl-Methanoazulen-5-One do in a beauty product?
It works by binding to scent receptors in the nose, creating the perception of a warm, woody aroma. In a product, it simply adds fragrance and does not actively affect the skin's structure or function.
Is Hexahydro-Tetramethyl-Methanoazulen-5-One safe for most people?
Generally considered safe for most people at the low concentrations used in cosmetics. However, it can cause skin irritation or allergic reactions in sensitive individuals, as with many fragrance ingredients.
Who should be careful with Hexahydro-Tetramethyl-Methanoazulen-5-One?
Individuals with sensitive skin, eczema, or known fragrance allergies
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.