Ingredient review
Undecylenoyl Sarcosine
INCI: UNDECYLENOYL SARCOSINE
A mild, amino-acid-based surfactant that cleanses without stripping the skin, making it a great choice for sensitive or dry skin types.
In plain English
Undecylenoyl Sarcosine is a gentle cleansing ingredient made from sarcosine (an amino acid) and undecylenic acid (a fatty acid from castor oil). It helps lift dirt, oil, and makeup from the skin without disrupting the natural moisture barrier. Because it is less harsh than traditional sulfates, it leaves skin feeling soft and comfortable rather than tight or dry.
Review score
Safety, usefulness, and evidence
Strong fit for many routines
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
- semi synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Easy yes for most routines
Undecylenoyl Sarcosine 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 Undecylenoyl Sarcosine.
- 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 semi-synthetic surfactant created by combining sarcosine (a naturally occurring amino acid) with undecylenic acid (derived from castor oil). It belongs to the family of amino-acid-based cleansers known for their mildness.
How it works
It works by reducing the surface tension between water and oil, allowing impurities to be rinsed away. Its molecular structure is similar to natural skin lipids, so it cleanses effectively while being gentle on the skin barrier. It also has some conditioning properties that help maintain a soft feel after washing.
Pros
Gentle on skin
Its amino-acid structure makes it much less irritating than traditional sulfates, so it cleanses without causing tightness or redness.
Supports barrier health
Because it doesn't strip natural oils, it helps maintain a healthy moisture barrier, which is especially beneficial for dry or compromised skin.
Cons and cautions
Mild cleansing power
It may not thoroughly remove heavy, long-wear makeup or very water-resistant sunscreens, so a double-cleanse step might be needed.
Higher cost
Amino-acid surfactants like this one are generally more expensive to produce, which can make products containing them pricier.
Best for
- People with dry or sensitive skin looking for a non-stripping cleanser
- Those who prefer amino-acid-based, sulfate-free cleansing formulas
Use caution if
- Individuals seeking a very high-foaming, deep-cleansing experience may find it too mild
Usage tips
Safety summary
Undecylenoyl Sarcosine is well-tolerated by most skin types and has a low irritation and comedogenic risk. It is considered safe for use in rinse-off and leave-on products at typical concentrations.
Research notes
Amino-acid surfactants like undecylenoyl sarcosine have been studied for their mildness and ability to preserve skin barrier function. While direct clinical studies on this specific compound are limited, the broader class is well-supported by dermatological research.
Common label clues
- Typical concentration
- 0.5% to 5% in rinse-off products; lower in leave-on formulas
- Regulatory status
- Approved for use in cosmetics in the EU, US, and many other regions. It is not classified as a hazardous substance under normal use conditions.
- Common uses
- Facial cleansers, Body washes, Shampoos, Leave-on toners
- Environmental note
- Derived from renewable castor oil and amino acids, it is generally considered more biodegradable than petroleum-based surfactants.
Good to know
- Undecylenoyl Sarcosine is often found in sulfate-free and pH-balanced cleansers.
- It is considered biodegradable and more environmentally friendly than some traditional surfactants.
Common questions
What is Undecylenoyl Sarcosine in beauty products?
Undecylenoyl Sarcosine is a gentle cleansing ingredient made from sarcosine (an amino acid) and undecylenic acid (a fatty acid from castor oil). It helps lift dirt, oil, and makeup from the skin without disrupting the natural moisture barrier. Because it is less harsh than traditional sulfates, it leaves skin feeling soft and comfortable rather than tight or dry.
What does Undecylenoyl Sarcosine do in a beauty product?
It works by reducing the surface tension between water and oil, allowing impurities to be rinsed away. Its molecular structure is similar to natural skin lipids, so it cleanses effectively while being gentle on the skin barrier. It also has some conditioning properties that help maintain a soft feel after washing.
Is Undecylenoyl Sarcosine safe for most people?
Undecylenoyl Sarcosine is well-tolerated by most skin types and has a low irritation and comedogenic risk. It is considered safe for use in rinse-off and leave-on products at typical concentrations.
Who should be careful with Undecylenoyl Sarcosine?
Individuals seeking a very high-foaming, deep-cleansing experience may find it too mild
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.