Ingredient review
Myristamidobutyl Guanidine Acetate
INCI: MYRISTAMIDOBUTYL GUANIDINE ACETATE
A synthetic hair conditioner that helps detangle and soften hair, but has limited published safety data.
In plain English
This ingredient is a man-made compound that sticks to the surface of your hair strands, making them feel smoother and easier to comb. It works like a lightweight coating that reduces friction between hairs, which can help prevent breakage and frizz. Think of it as a gentle, temporary 'smoothing film' for your hair, not a deep repair treatment.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is still emerging, so marketing claims deserve extra caution.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- synthetic
- Evidence
- emerging
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Myristamidobutyl Guanidine Acetate 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 Myristamidobutyl Guanidine Acetate.
- 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
emergingThe ingredient may be promising, but claims should be treated more cautiously.
What it is
Myristamidobutyl Guanidine Acetate is a synthetic quaternary ammonium compound derived from myristic acid (a fatty acid found in coconut oil) and guanidine. It is designed to condition hair by reducing static and improving slip.
How it works
The molecule has a positive charge that binds to the negatively charged surface of damaged or dry hair. This neutralizes static electricity, reduces friction between strands, and leaves hair feeling softer and more manageable. It does not penetrate the hair shaft but works on the outer cuticle layer.
Pros
Effective detangler
Reduces combing friction, which can minimize hair breakage during styling.
Lightweight feel
Does not leave a heavy, greasy residue, making it suitable for fine to normal hair types.
Cons and cautions
Limited research
There are few peer-reviewed studies on this specific ingredient, so its long-term effects are not well understood.
Surface-only effect
It only coats the hair temporarily and does not repair structural damage or split ends.
Best for
- People with dry, frizzy, or damaged hair seeking a lightweight detangler
- Those who want a gentle conditioner for daily use
Use caution if
- Individuals with very fine or oily hair who may experience limpness
- Anyone with known sensitivity to synthetic quaternary ammonium compounds
Usage tips
Safety summary
Generally considered safe at typical use concentrations in rinse-off hair products. However, due to limited published safety data, it is best used as directed and avoided if you have sensitive skin or scalp conditions.
Research notes
No major clinical studies or safety panel reviews were found specifically for Myristamidobutyl Guanidine Acetate. Its safety is inferred from similar quaternary ammonium compounds used in cosmetics.
Common label clues
- Typical concentration
- 0.1% to 1%
- Regulatory status
- Approved for use in cosmetics in the EU, US, and other major markets, but not individually reviewed by the Cosmetic Ingredient Review (CIR) panel as of 2025.
- Common uses
- Shampoos, Conditioners, Hair treatments
- Environmental note
- As a synthetic compound, its biodegradability and aquatic toxicity are not well documented. Choose products from brands that prioritize eco-friendly formulations.
Good to know
- This ingredient is often listed near the end of ingredient lists, indicating a low concentration.
- It is not known to be a common allergen, but patch testing is always wise for new products.
Common questions
What is Myristamidobutyl Guanidine Acetate in beauty products?
This ingredient is a man-made compound that sticks to the surface of your hair strands, making them feel smoother and easier to comb. It works like a lightweight coating that reduces friction between hairs, which can help prevent breakage and frizz. Think of it as a gentle, temporary 'smoothing film' for your hair, not a deep repair treatment.
What does Myristamidobutyl Guanidine Acetate do in a beauty product?
The molecule has a positive charge that binds to the negatively charged surface of damaged or dry hair. This neutralizes static electricity, reduces friction between strands, and leaves hair feeling softer and more manageable. It does not penetrate the hair shaft but works on the outer cuticle layer.
Is Myristamidobutyl Guanidine Acetate safe for most people?
Generally considered safe at typical use concentrations in rinse-off hair products. However, due to limited published safety data, it is best used as directed and avoided if you have sensitive skin or scalp conditions.
Who should be careful with Myristamidobutyl Guanidine Acetate?
Individuals with very fine or oily hair who may experience limpness Anyone with known sensitivity to synthetic 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.