Ingredient review
Cis-6-Nonanal
INCI: CIS-6-NONANAL
A synthetic fragrance compound that adds a fresh, green scent but offers no skincare benefits and may cause sensitivity in some individuals.
In plain English
Cis-6-Nonanal is a man-made chemical that smells like fresh green melon or cucumber. It's added to skincare and beauty products purely for its pleasant scent. It doesn't moisturize, treat, or improve your skin in any way. While generally considered safe in tiny amounts, it can be a potential irritant for people with very sensitive skin or fragrance allergies.
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
Cis-6-Nonanal 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 Cis-6-Nonanal.
- 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 aldehyde compound used as a fragrance ingredient in cosmetics and personal care products. It is not naturally derived but is designed to mimic the fresh, green scent of certain fruits and plants.
How it works
It works by evaporating from the product's surface and interacting with olfactory receptors in the nose, creating the perception of a fresh, green scent. It does not have any active skincare function.
Pros
Pleasant fresh scent
Adds a light, green, melon-like fragrance that many find appealing and refreshing in skincare products.
Low risk for most
At the very low concentrations used, it is generally non-irritating and non-comedogenic for the majority of skin types.
Cons and cautions
No skincare benefit
This ingredient is purely for scent. It does not hydrate, soothe, or provide any active skin improvement.
Potential allergen
As a synthetic fragrance, it can trigger contact dermatitis or allergic reactions in people with fragrance sensitivities, leading to redness or irritation.
Best for
- People who enjoy scented skincare products
- Those without fragrance sensitivities
Use caution if
- Individuals with known fragrance allergies or very sensitive skin
Usage tips
Safety summary
Cis-6-Nonanal is considered safe for use in cosmetics at the low concentrations typically employed. However, like many fragrance ingredients, it can cause skin irritation or allergic reactions in sensitive individuals. Regulatory bodies require it to be listed on ingredient labels, allowing consumers to avoid it if needed.
Research notes
Research on Cis-6-Nonanal primarily focuses on its sensory properties and safety as a fragrance ingredient. It is not associated with significant toxicity at cosmetic use levels, but it is a known potential allergen, consistent with other aldehyde-based fragrances.
Common label clues
- Typical concentration
- Typically used at very low concentrations (less than 0.1%) due to its strong scent.
- Regulatory status
- Approved for use as a fragrance ingredient in cosmetics by major regulatory bodies including the FDA (in the US) and the EU Cosmetics Regulation, subject to concentration limits and labeling requirements for allergens.
- Common uses
- Fragranced skincare, Perfumes, Body lotions, Cleansers
- Environmental note
- As a synthetic compound, its environmental impact is generally low due to the tiny quantities used, but it is not biodegradable in all conditions.
Good to know
- Cis-6-Nonanal is often used in very small amounts to create a 'fresh out of the shower' or 'green' scent profile.
- It is not a preservative, active, or functional ingredient—its only role is fragrance.
Common questions
What is Cis-6-Nonanal in beauty products?
Cis-6-Nonanal is a man-made chemical that smells like fresh green melon or cucumber. It's added to skincare and beauty products purely for its pleasant scent. It doesn't moisturize, treat, or improve your skin in any way. While generally considered safe in tiny amounts, it can be a potential irritant for people with very sensitive skin or fragrance allergies.
What does Cis-6-Nonanal do in a beauty product?
It works by evaporating from the product's surface and interacting with olfactory receptors in the nose, creating the perception of a fresh, green scent. It does not have any active skincare function.
Is Cis-6-Nonanal safe for most people?
Cis-6-Nonanal is considered safe for use in cosmetics at the low concentrations typically employed. However, like many fragrance ingredients, it can cause skin irritation or allergic reactions in sensitive individuals. Regulatory bodies require it to be listed on ingredient labels, allowing consumers to avoid it if needed.
Who should be careful with Cis-6-Nonanal?
Individuals with known fragrance allergies or very sensitive skin
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.