Ingredient review
Laurdimonium Hydroxypropyl Hydrolyzed Keratin
INCI: LAURDIMONIUM HYDROXYPROPYL HYDROLYZED KERATIN
A gentle, modified keratin that helps smooth and strengthen hair without the harshness of unmodified proteins.
In plain English
This is a version of keratin (the protein that makes up your hair and nails) that has been chemically tweaked to carry a positive charge. That positive charge helps it stick to the negatively charged surface of damaged hair, so it can fill in gaps, reduce frizz, and make hair feel softer and stronger. It's also used in some skin products to form a light, protective film.
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
- semi synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Laurdimonium Hydroxypropyl Hydrolyzed Keratin 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 Laurdimonium Hydroxypropyl Hydrolyzed Keratin.
- 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 ingredient made by attaching a fatty quaternary ammonium group (laurdimonium) to hydrolyzed keratin (broken-down keratin protein). This gives it a positive charge and makes it more compatible with hair and skin.
How it works
The positive charge attracts it to the negative charge on damaged hair and skin. It deposits a thin, flexible film that smooths the cuticle, reduces static, and temporarily repairs surface damage. It also helps other conditioning ingredients stick better.
Pros
Stronger, smoother hair
The positive charge helps it bind to damaged areas, temporarily filling gaps and reducing breakage for a smoother feel.
Gentle on skin
Unlike some harsh surfactants, this modified keratin is considered low-irritation and non-comedogenic, so it's safe for most skin types.
Cons and cautions
Can cause buildup
Because it sticks so well, using it too often can leave a coating that makes hair feel stiff or dull, especially for fine hair.
Not a permanent fix
The smoothing and strengthening effects are temporary and wash out, so you need to keep using it to maintain results.
Best for
- People with damaged, color-treated, or heat-styled hair
- Those seeking frizz control and smoother texture
Use caution if
- People with very fine or low-porosity hair who are prone to protein overload
Usage tips
Safety summary
Considered safe for topical use at typical concentrations. Low irritation and comedogenic risk. No significant safety concerns reported in cosmetic use.
Research notes
Studies show quaternized proteins like this one improve hair strength and reduce breakage compared to unmodified proteins. Evidence is mostly from in vitro and product testing, not large clinical trials.
Common label clues
- Typical concentration
- 0.1% to 2%
- Regulatory status
- Approved for use in cosmetics globally, including by the EU CosIng database and the US FDA (as part of cosmetic ingredients). No known restrictions.
- Common uses
- Shampoos, Conditioners, Leave-in treatments, Hair masks, Styling products
- Environmental note
- Derived from animal keratin (often sheep wool) and modified synthetically. Not vegan. Biodegradability is moderate; check brand sourcing for sustainability claims.
Good to know
- This ingredient is often listed near the middle or end of an ingredient list because it's used at low concentrations.
- It works well with other conditioning agents like fatty alcohols and silicones.
Common questions
What is Laurdimonium Hydroxypropyl Hydrolyzed Keratin in beauty products?
This is a version of keratin (the protein that makes up your hair and nails) that has been chemically tweaked to carry a positive charge. That positive charge helps it stick to the negatively charged surface of damaged hair, so it can fill in gaps, reduce frizz, and make hair feel softer and stronger. It's also used in some skin products to form a light, protective film.
What does Laurdimonium Hydroxypropyl Hydrolyzed Keratin do in a beauty product?
The positive charge attracts it to the negative charge on damaged hair and skin. It deposits a thin, flexible film that smooths the cuticle, reduces static, and temporarily repairs surface damage. It also helps other conditioning ingredients stick better.
Is Laurdimonium Hydroxypropyl Hydrolyzed Keratin safe for most people?
Considered safe for topical use at typical concentrations. Low irritation and comedogenic risk. No significant safety concerns reported in cosmetic use.
Who should be careful with Laurdimonium Hydroxypropyl Hydrolyzed Keratin?
People with very fine or low-porosity hair who are prone to protein overload
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.