Ingredient review

2-Undecenenitrile

INCI: 2-UNDECENENITRILE

2-Undecenenitrile is a synthetic fragrance ingredient that adds a fresh, citrus-like scent but may cause skin irritation in sensitive individuals.

beautyskincarefragrance

In plain English

2-Undecenenitrile is a man-made chemical that gives products a pleasant, fresh smell, often described as citrusy or green. It is added in tiny amounts to perfumes, lotions, and cleansers. Because it is a fragrance ingredient, it can sometimes irritate sensitive skin or trigger allergic reactions, especially in people with fragrance sensitivities.

Quick decision guide

Useful, but context matters

2-Undecenenitrile can be useful, but watch for some irritation potential.

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 2-Undecenenitrile.
  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

moderate

Can bother some users, especially with frequent use, damaged skin, or strong companion ingredients.

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

2-Undecenenitrile is a synthetic nitrile compound, meaning it contains a carbon-nitrogen triple bond. It is not found in nature and is created in a lab specifically for its strong, pleasant odor profile.

How it works

In a cosmetic product, 2-Undecenenitrile acts solely as a fragrance ingredient. It evaporates from the skin after application, releasing its scent molecules into the air. It does not provide any moisturizing, anti-aging, or other skincare benefits.

Pros

Pleasant scent

Adds a fresh, citrus-like fragrance that many people find appealing in lotions, cleansers, and perfumes.

Low comedogenic risk

Unlikely to clog pores, making it suitable for most skin types when used in low concentrations.

Cons and cautions

Potential irritant

Can cause redness, itching, or stinging in people with sensitive skin or fragrance allergies, especially at higher concentrations.

No skincare benefit

Provides only fragrance—no moisturizing, soothing, or anti-aging properties—so it adds no functional value to a skincare routine.

Best for

  • People who enjoy scented products and have no history of fragrance allergies
  • Those looking for a fresh, citrusy scent in their routine

Use caution if

  • Individuals with sensitive skin, eczema, or known fragrance allergies should avoid products containing this ingredient

Usage tips

If you have sensitive skin, patch test a scented product on your inner arm before applying it to your face or body.
Look for products labeled 'fragrance-free' if you want to avoid synthetic fragrance ingredients like 2-Undecenenitrile.

Safety summary

2-Undecenenitrile is considered safe for most people when used at low concentrations in cosmetics. However, it can cause skin irritation or allergic reactions in sensitive individuals. Regulatory bodies in the EU require it to be labeled as a potential allergen.

Research notes

Research on 2-Undecenenitrile is limited, but it is recognized by fragrance safety panels as a potential skin sensitizer. Studies focus on its irritation potential rather than any therapeutic benefits.

Common label clues

Typical concentration
Typically used at very low concentrations (below 1%) due to its strong scent and potential for skin sensitization.
Regulatory status
Approved for use in cosmetics in the US and EU. In the EU, it must be listed on the label if its concentration exceeds 0.01% in leave-on products or 0.001% in rinse-off products, due to its potential as an allergen.
Common uses
Fragranced products, Perfumes, Body lotions, Cleansers
Environmental note
As a synthetic compound, its environmental impact is not well-studied, but it is used in very small amounts and is unlikely to accumulate in the environment.

Good to know

  • 2-Undecenenitrile is often listed simply as 'fragrance' or 'parfum' on ingredient labels, so it may not appear by name.
  • This ingredient is regulated as a fragrance allergen in the EU, requiring labeling if present above certain levels.

Common questions

What is 2-Undecenenitrile in beauty products?

2-Undecenenitrile is a man-made chemical that gives products a pleasant, fresh smell, often described as citrusy or green. It is added in tiny amounts to perfumes, lotions, and cleansers. Because it is a fragrance ingredient, it can sometimes irritate sensitive skin or trigger allergic reactions, especially in people with fragrance sensitivities.

What does 2-Undecenenitrile do in a beauty product?

In a cosmetic product, 2-Undecenenitrile acts solely as a fragrance ingredient. It evaporates from the skin after application, releasing its scent molecules into the air. It does not provide any moisturizing, anti-aging, or other skincare benefits.

Is 2-Undecenenitrile safe for most people?

2-Undecenenitrile is considered safe for most people when used at low concentrations in cosmetics. However, it can cause skin irritation or allergic reactions in sensitive individuals. Regulatory bodies in the EU require it to be labeled as a potential allergen.

Who should be careful with 2-Undecenenitrile?

Individuals with sensitive skin, eczema, or known fragrance allergies should avoid products containing this ingredient

Research sources

European Chemicals Agency (ECHA) - 2-UndecenenitrileOpenCosIng - EU Cosmetic Ingredient DatabaseOpen

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.