Ingredient review

Cyclohexyl-4-Methylpentan-2-One

INCI: CYCLOHEXYL-4-METHYLPENTAN-2-ONE

A synthetic fragrance compound that adds scent but offers no skincare benefit; generally safe at low levels but may cause irritation in sensitive individuals.

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In plain English

This is a man-made chemical added to give products a pleasant smell, often described as fresh, fruity, or floral. It doesn't moisturize, treat, or improve your skin—it's purely for scent. Because it's a fragrance ingredient, it can sometimes cause irritation or allergic reactions, especially if you have sensitive skin.

Review score

Safety, usefulness, and evidence

3.5Good
3.5/ 5

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
How reviews are scored

Quick decision guide

Useful, but context matters

Cyclohexyl-4-Methylpentan-2-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.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging Cyclohexyl-4-Methylpentan-2-One.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. 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

low

Less likely to sting, burn, or bother most users, though sensitive skin can still react.

Clogging risk

low

Less likely to feel heavy or contribute to clogged pores for most skin types.

Evidence level

moderate

There is useful support, but formula details and claim strength still matter.

What it is

A synthetic ketone compound used as a fragrance ingredient in cosmetics and personal care products. It is not derived from natural sources and is created through chemical synthesis.

How it works

It evaporates from the skin or hair after application, releasing a scent that is perceived by the nose. It does not interact with the skin's biology or provide any functional benefit beyond fragrance.

Pros

Pleasant scent

Adds a fresh, fruity, or floral note that enhances the sensory experience of using a product.

Low irritation at low levels

When used in small amounts in rinse-off products, it is generally well-tolerated by most people.

Cons and cautions

No skincare benefit

This ingredient does nothing for your skin—it's purely for fragrance, so it adds no value to your skincare routine.

Potential allergen

As a synthetic fragrance, it can cause contact dermatitis or allergic reactions in sensitive individuals, especially with repeated use.

Best for

  • People who enjoy scented products and have no history of fragrance allergies
  • Those using rinse-off products like body wash where contact time is short

Use caution if

  • Individuals with sensitive, reactive, or eczema-prone skin
  • Anyone with a known allergy or sensitivity to synthetic fragrances

Usage tips

If you have sensitive skin, patch test a scented product on a small area before full use.
Consider fragrance-free alternatives if you experience redness, itching, or stinging from scented products.

Safety summary

Generally recognized as safe for use in cosmetics at low concentrations. However, like many fragrance ingredients, it can cause skin irritation or allergic reactions in susceptible individuals. The Cosmetic Ingredient Review (CIR) and IFRA have evaluated similar ketone fragrance ingredients and found them safe within specified limits.

Research notes

Limited peer-reviewed studies specifically on cyclohexyl-4-methylpentan-2-one, but it belongs to a class of ketone fragrances that have been assessed for skin sensitization and irritation. The IFRA standards provide guidance on safe usage levels.

Common label clues

Typical concentration
Typically used at very low levels (less than 1%) in rinse-off and leave-on products
Regulatory status
Approved for use in cosmetics in the EU, US, and many other countries, subject to concentration limits set by IFRA and local regulations.
Common uses
Fragranced lotions, Perfumes, Body washes, Hair products
Environmental note
As a synthetic compound, it may persist in the environment after washing off; however, its low concentration in products minimizes impact.

Good to know

  • Fragrance ingredients are often listed simply as 'fragrance' or 'parfum' on labels, but this specific compound may appear under its INCI name.
  • Regulatory bodies like the IFRA (International Fragrance Association) set safety limits for fragrance ingredients in cosmetics.

Common questions

What is Cyclohexyl-4-Methylpentan-2-One in beauty products?

This is a man-made chemical added to give products a pleasant smell, often described as fresh, fruity, or floral. It doesn't moisturize, treat, or improve your skin—it's purely for scent. Because it's a fragrance ingredient, it can sometimes cause irritation or allergic reactions, especially if you have sensitive skin.

What does Cyclohexyl-4-Methylpentan-2-One do in a beauty product?

It evaporates from the skin or hair after application, releasing a scent that is perceived by the nose. It does not interact with the skin's biology or provide any functional benefit beyond fragrance.

Is Cyclohexyl-4-Methylpentan-2-One safe for most people?

Generally recognized as safe for use in cosmetics at low concentrations. However, like many fragrance ingredients, it can cause skin irritation or allergic reactions in susceptible individuals. The Cosmetic Ingredient Review (CIR) and IFRA have evaluated similar ketone fragrance ingredients and found them safe within specified limits.

Who should be careful with Cyclohexyl-4-Methylpentan-2-One?

Individuals with sensitive, reactive, or eczema-prone skin Anyone with a known allergy or sensitivity to synthetic fragrances

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.