Ingredient review

Potassium Undecylenoyl Hydrolyzed Rice Protein

INCI: POTASSIUM UNDECYLENOYL HYDROLYZED RICE PROTEIN

A mild, plant-derived surfactant that cleanses gently and is well-tolerated by sensitive skin.

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In plain English

This ingredient is a gentle soap-like molecule made by combining rice protein with a fatty acid from castor oil. It helps water mix with dirt and oil so they can be rinsed away, but it's much less harsh than traditional sulfates. Because it's derived from rice protein, it can also leave a light conditioning effect on skin and hair, making it popular in products for sensitive skin or delicate hair types.

Review score

Safety, usefulness, and evidence

4.3Good
4.3/ 5

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
How reviews are scored

Quick decision guide

Easy yes for most routines

Potassium Undecylenoyl Hydrolyzed Rice Protein 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 Potassium Undecylenoyl Hydrolyzed Rice Protein.
  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 semi-synthetic surfactant created by reacting undecylenic acid (from castor oil) with hydrolyzed rice protein. The result is a mild cleansing molecule that is anionic (negatively charged) and works well in both clear and creamy formulas.

How it works

In a cosmetic product, this ingredient reduces the surface tension between water and oil, allowing dirt, sebum, and makeup to be emulsified and washed away. Its protein backbone also helps it deposit a thin film on skin or hair, providing a soft, non-stripping feel after rinsing.

Pros

Very gentle on skin

Unlike sodium lauryl sulfate, this surfactant has a large protein head that makes it less penetrating and irritating, ideal for compromised or sensitive skin barriers.

Conditioning properties

The rice protein component leaves a light, protective film on skin and hair, reducing the tight, dry feeling many cleansers cause.

Cons and cautions

Lower cleansing power

It may not fully remove heavy, long-wear makeup or very oily sunscreen in a single wash, requiring a double-cleanse routine.

Less foam

Users accustomed to rich, bubbly lather may find this ingredient produces a thinner, creamier foam, which can feel less satisfying.

Best for

  • People with dry, sensitive, or eczema-prone skin
  • Those looking for a sulfate-free cleanser for daily use

Use caution if

  • Individuals who prefer high-foam, squeaky-clean cleansers

Usage tips

Use as part of a double-cleanse routine if wearing heavy makeup or water-resistant sunscreen.
Pair with a moisturizer afterward to maintain hydration, especially if you have dry skin.

Safety summary

Potassium Undecylenoyl Hydrolyzed Rice Protein is considered safe for use in cosmetics. It has low irritation and sensitization potential, and no significant toxicity concerns have been reported in standard safety assessments. It is well-tolerated even by sensitive skin types.

Research notes

While not as extensively studied as some common surfactants, available safety data and decades of use in mild formulations support its safety profile. Its protein-based structure is known to reduce irritation compared to harsher anionic surfactants.

Common label clues

Typical concentration
1–10% in rinse-off products
Regulatory status
Approved for use in cosmetics globally, including by the EU CosIng database and the US FDA (as a cosmetic ingredient). No concentration restrictions are typically imposed.
Common uses
Facial cleansers, Shampoos, Body washes, Baby care products
Environmental note
Derived from renewable plant sources (rice and castor oil) and is readily biodegradable, making it a more environmentally friendly surfactant choice.

Good to know

  • This ingredient is often listed near the middle or end of an ingredient list because it is effective at low concentrations.
  • It is considered biodegradable and is often chosen for 'green' or eco-friendly formulations.

Common questions

What is Potassium Undecylenoyl Hydrolyzed Rice Protein in beauty products?

This ingredient is a gentle soap-like molecule made by combining rice protein with a fatty acid from castor oil. It helps water mix with dirt and oil so they can be rinsed away, but it's much less harsh than traditional sulfates. Because it's derived from rice protein, it can also leave a light conditioning effect on skin and hair, making it popular in products for sensitive skin or delicate hair types.

What does Potassium Undecylenoyl Hydrolyzed Rice Protein do in a beauty product?

In a cosmetic product, this ingredient reduces the surface tension between water and oil, allowing dirt, sebum, and makeup to be emulsified and washed away. Its protein backbone also helps it deposit a thin film on skin or hair, providing a soft, non-stripping feel after rinsing.

Is Potassium Undecylenoyl Hydrolyzed Rice Protein safe for most people?

Potassium Undecylenoyl Hydrolyzed Rice Protein is considered safe for use in cosmetics. It has low irritation and sensitization potential, and no significant toxicity concerns have been reported in standard safety assessments. It is well-tolerated even by sensitive skin types.

Who should be careful with Potassium Undecylenoyl Hydrolyzed Rice Protein?

Individuals who prefer high-foam, squeaky-clean cleansers

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.