Ingredient review
Myrtrimonium Bromide
INCI: Myrtrimonium Bromide
An effective preservative and antistatic agent, but may cause irritation for sensitive skin or eyes.
In plain English
Myrtrimonium Bromide is a synthetic ingredient that helps keep cosmetic products free from microbes and reduces static electricity in hair. It belongs to a group of chemicals called quaternary ammonium compounds, which are positively charged and cling to negatively charged surfaces like hair and skin. While it works well for its intended purposes, it can be drying or irritating for some people, especially those with sensitive skin or scalp conditions.
Review score
Safety, usefulness, and evidence
Useful in the right context, but not low-maintenance
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
Read the cautions before using
Myrtrimonium Bromide 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 Myrtrimonium Bromide.
- 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
A quaternary ammonium salt (a type of positively charged molecule) used primarily as a preservative and antistatic agent in personal care products.
How it works
As a preservative, it disrupts the cell membranes of bacteria and fungi, preventing microbial growth. As an antistatic agent, its positive charge neutralizes negative charges on hair, reducing flyaways and making hair easier to manage.
Pros
Effective preservation
Helps keep products free from harmful bacteria and fungi, extending their usable life.
Reduces hair static
Neutralizes electrical charges on hair, making it smoother and less prone to flyaways.
Cons and cautions
Potential irritation
Can cause stinging, redness, or dryness on sensitive skin or if it contacts eyes.
May be drying
Frequent use in leave-on products might strip natural oils, leading to dry or brittle hair.
Best for
- People looking for a preservative in rinse-off products
- Those wanting to reduce static in hair without heavy silicones
Use caution if
- Individuals with sensitive skin, eczema, or known allergies to quaternary ammonium compounds
Usage tips
Safety summary
Generally safe at low concentrations in rinse-off products, but can cause irritation in sensitive individuals. Avoid contact with eyes and broken skin.
Research notes
Studies confirm its antimicrobial efficacy and antistatic properties. Irritation potential is dose-dependent, with higher concentrations linked to skin and eye irritation.
Common label clues
- Typical concentration
- Typically used at 0.1% to 1% in rinse-off products
- Regulatory status
- Approved for use in cosmetics in the EU, US, and many other regions, with concentration limits typically under 1% in rinse-off products.
- Common uses
- Conditioners, Hair rinses, Leave-in treatments
- Environmental note
- Quaternary ammonium compounds can be persistent in water and may affect aquatic life; however, levels in personal care products are generally low.
Good to know
- Often found in combination with other preservatives to broaden antimicrobial activity
- Less common in modern 'clean beauty' formulations due to irritation concerns
Common questions
What is Myrtrimonium Bromide in beauty products?
Myrtrimonium Bromide is a synthetic ingredient that helps keep cosmetic products free from microbes and reduces static electricity in hair. It belongs to a group of chemicals called quaternary ammonium compounds, which are positively charged and cling to negatively charged surfaces like hair and skin. While it works well for its intended purposes, it can be drying or irritating for some people, especially those with sensitive skin or scalp conditions.
What does Myrtrimonium Bromide do in a beauty product?
As a preservative, it disrupts the cell membranes of bacteria and fungi, preventing microbial growth. As an antistatic agent, its positive charge neutralizes negative charges on hair, reducing flyaways and making hair easier to manage.
Is Myrtrimonium Bromide safe for most people?
Generally safe at low concentrations in rinse-off products, but can cause irritation in sensitive individuals. Avoid contact with eyes and broken skin.
Who should be careful with Myrtrimonium Bromide?
Individuals with sensitive skin, eczema, or known allergies to quaternary ammonium compounds
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.