Ingredient review
C13-15 Pareth-21
INCI: C13-15 PARETH-21
A gentle synthetic emulsifier that helps mix oil and water, commonly used in cleansers and lotions with a low irritation risk.
In plain English
C13-15 Pareth-21 is a man-made ingredient that helps oil and water blend together in products like cleansers and lotions. It is a type of surfactant, which means it can also help lift dirt and oil from your skin so they rinse away easily. It is considered very gentle and unlikely to clog pores or cause irritation for most people.
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
C13-15 Pareth-21 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 C13-15 Pareth-21.
- 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
C13-15 Pareth-21 is a synthetic surfactant and emulsifier made from a fatty alcohol (C13-15 alcohols) reacted with ethylene oxide. It belongs to the 'pareth' family of ingredients, which are known for their mild cleansing and emulsifying properties.
How it works
In a cosmetic product, C13-15 Pareth-21 reduces the surface tension between oil and water, allowing them to mix into a stable emulsion. This helps create smooth, creamy textures in lotions and cleansers. As a surfactant, it also helps water rinse away oil and dirt from the skin's surface.
Pros
Gentle on skin
C13-15 Pareth-21 has a low irritation risk, making it suitable for sensitive skin types and daily use in cleansers and moisturizers.
Effective emulsifier
It reliably blends oil and water, helping create smooth, stable lotions and creams that feel pleasant on the skin.
Cons and cautions
Synthetic origin
As a man-made ingredient, it may not appeal to consumers seeking natural or plant-based formulations.
Potential for drying
In high concentrations or in products without enough moisturizing ingredients, it can strip natural oils and leave skin feeling dry.
Best for
- People with normal to dry skin looking for gentle cleansers
- Anyone using lotions or creams that need a stable, non-irritating emulsifier
Use caution if
- Those strictly avoiding all synthetic ingredients
- Individuals with known sensitivity to ethoxylated ingredients (rare)
Usage tips
Safety summary
C13-15 Pareth-21 is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential, making it suitable for most skin types. Rare allergic reactions are possible, as with any ingredient.
Research notes
Safety assessments by expert panels (e.g., CIR) have reviewed ethoxylated alcohols and found them safe for cosmetic use when formulated properly. Specific studies on C13-15 Pareth-21 are limited, but its chemical class is well-studied and considered low-risk.
Common label clues
- Typical concentration
- 1% to 10%
- Regulatory status
- Approved for use in cosmetics in the US, EU, and many other regions. No specific restrictions at typical use levels.
- Common uses
- Cleansers, Shampoos, Body washes, Lotions
- Environmental note
- As a synthetic ethoxylate, its biodegradability varies. Some ethoxylated surfactants can persist in the environment, but C13-15 Pareth-21 is generally considered to have moderate biodegradability.
Good to know
- C13-15 Pareth-21 is part of the 'pareth' family, which are ethoxylated alcohols commonly used in mild cleansers.
- It is often found in sulfate-free formulations as a gentler alternative to sodium lauryl sulfate.
Common questions
What is C13-15 Pareth-21 in beauty products?
C13-15 Pareth-21 is a man-made ingredient that helps oil and water blend together in products like cleansers and lotions. It is a type of surfactant, which means it can also help lift dirt and oil from your skin so they rinse away easily. It is considered very gentle and unlikely to clog pores or cause irritation for most people.
What does C13-15 Pareth-21 do in a beauty product?
In a cosmetic product, C13-15 Pareth-21 reduces the surface tension between oil and water, allowing them to mix into a stable emulsion. This helps create smooth, creamy textures in lotions and cleansers. As a surfactant, it also helps water rinse away oil and dirt from the skin's surface.
Is C13-15 Pareth-21 safe for most people?
C13-15 Pareth-21 is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential, making it suitable for most skin types. Rare allergic reactions are possible, as with any ingredient.
Who should be careful with C13-15 Pareth-21?
Those strictly avoiding all synthetic ingredients Individuals with known sensitivity to ethoxylated ingredients (rare)
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.