Ingredient review
PEG-5 Stearyl Ammonium Chloride
INCI: PEG-5 Stearyl Ammonium Chloride
A synthetic conditioning agent that reduces static and softens hair, but may cause irritation for sensitive scalps at higher concentrations.
In plain English
This is a man-made ingredient that helps hair feel smooth and reduces frizz by coating each strand with a thin, positively charged layer. It works like a gentle fabric softener for your hair, making it easier to comb and less likely to fly away. In skincare, it can add a silky feel but is mostly used in hair products.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Main practical flags: irritation is moderate; clogging risk is low.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- moderate
- Clogging risk
- low
Quick decision guide
Useful, but context matters
PEG-5 Stearyl Ammonium Chloride 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.
- Step 1Start with the score, then check the irritation and clogging risk before judging PEG-5 Stearyl Ammonium Chloride.
- 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
moderateCan bother some users, especially with frequent use, damaged skin, or strong companion ingredients.
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
PEG-5 Stearyl Ammonium Chloride is a quaternary ammonium salt (a type of positively charged molecule) that is chemically modified with polyethylene glycol (PEG) chains to make it milder and more water-friendly. It belongs to the same family as behentrimonium chloride, a common conditioner ingredient.
How it works
The positively charged head of the molecule is attracted to the negatively charged surface of damaged hair or skin. It forms a thin, invisible film that neutralizes static electricity, smooths the cuticle, and reduces friction between strands. This makes hair feel softer, look shinier, and tangle less.
Pros
Effective static control
Neutralizes electrical charges on hair, reducing flyaways and making hair easier to style, especially in dry or winter conditions.
Improves combing ease
Coats each hair strand to reduce friction, so you can detangle wet or dry hair with less breakage and pulling.
Cons and cautions
Potential scalp irritation
At concentrations above 2% or with frequent use, this ingredient may cause itching, redness, or flaking for people with sensitive scalps.
Synthetic and not fully biodegradable
As a PEG-modified quat, it is derived from petrochemicals and may persist in the environment longer than natural alternatives.
Best for
- People with dry, damaged, or frizzy hair seeking extra conditioning
- Those who use heat styling tools and want to reduce static
Use caution if
- Individuals with very sensitive scalps or contact dermatitis to quaternary ammonium compounds
- Those following a strictly natural or plant-based routine
Usage tips
Safety summary
PEG-5 Stearyl Ammonium Chloride is considered safe for use in rinse-off hair products at typical concentrations. The Cosmetic Ingredient Review (CIR) panel has reviewed similar quaternary ammonium compounds and found them safe when formulated to be non-irritating. However, individuals with very sensitive skin or scalp may experience mild irritation, especially in leave-on formulas.
Research notes
Research on quaternary ammonium compounds shows they are effective conditioning agents with low acute toxicity. Studies specific to PEG-5 Stearyl Ammonium Chloride are limited, but the broader class is well-documented for antistatic and conditioning properties. The CIR has not issued a specific monograph for this exact ingredient, but its structural analogs are considered safe within typical use concentrations.
Common label clues
- Typical concentration
- 0.1% to 2% in rinse-off products; lower in leave-on formulas
- Regulatory status
- Approved for use in cosmetics in the EU, US, and many other regions. The EU CosIng database lists it as a hair conditioning and antistatic agent with no specific concentration restrictions, though manufacturers self-regulate for safety.
- Common uses
- Conditioners, Hair masks, Leave-in treatments, Shampoos, Body washes
- Environmental note
- As a synthetic quaternary ammonium compound, it may not be readily biodegradable. Some wastewater treatment plants can partially remove it, but it can accumulate in aquatic sediments. Look for products with eco-friendly packaging or brands that prioritize biodegradability.
Good to know
- PEG-5 Stearyl Ammonium Chloride is often listed near the middle or end of ingredient lists because it is used at low concentrations.
- It is sometimes combined with fatty alcohols (like cetearyl alcohol) to create a creamier, more spreadable conditioner base.
Common questions
What is PEG-5 Stearyl Ammonium Chloride in beauty products?
This is a man-made ingredient that helps hair feel smooth and reduces frizz by coating each strand with a thin, positively charged layer. It works like a gentle fabric softener for your hair, making it easier to comb and less likely to fly away. In skincare, it can add a silky feel but is mostly used in hair products.
What does PEG-5 Stearyl Ammonium Chloride do in a beauty product?
The positively charged head of the molecule is attracted to the negatively charged surface of damaged hair or skin. It forms a thin, invisible film that neutralizes static electricity, smooths the cuticle, and reduces friction between strands. This makes hair feel softer, look shinier, and tangle less.
Is PEG-5 Stearyl Ammonium Chloride safe for most people?
PEG-5 Stearyl Ammonium Chloride is considered safe for use in rinse-off hair products at typical concentrations. The Cosmetic Ingredient Review (CIR) panel has reviewed similar quaternary ammonium compounds and found them safe when formulated to be non-irritating. However, individuals with very sensitive skin or scalp may experience mild irritation, especially in leave-on formulas.
Who should be careful with PEG-5 Stearyl Ammonium Chloride?
Individuals with very sensitive scalps or contact dermatitis to quaternary ammonium compounds Those following a strictly natural or plant-based routine
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.