CONDITIONING AGENT
Behentrimonium Methosulfate
- conditioning agent
A mild cationic conditioner known for heavy detangling with a light rinse-out feel. Common in curly-hair conditioners.
- products in our library
- 339
- of researched products
- 9%
- on the label, in our conditioners
- usually #6
- most common in
- Conditioner
- in water
- Water-dispersible
At a glance
Four named levels, read from this ingredient’s chemical class, its charge, its solubility, or where it sits on the labels we have. More dots means more of the property named — never “better”.
How much of it is left on hair between washes.
What it takes to get it off the hair again.
Whether hair pulls it in or pushes it away — read from charge.
How much easier it makes a comb pass.
| Property | Level | Out of |
|---|---|---|
| Buildup risk | Low | 2 of 5 |
| Rinse-out behaviour | Stays where hair is damaged | 2 of 5 |
| Adhesion | Clings to damage | 5 of 5 |
| Slip | High | 5 of 5 |
What it does for a formula
What Behentrimonium Methosulfate does
The general function first, then how the role changes by product type where we have researched it.
Positive charge is drawn to the negatively charged, worn patches of a strand.
The measurable part of conditioning: less force to pull a comb through.
Without one, a cream separates in the bottle.
Positive charge holds it on the hair through the rinse.
Charge
Positively charged, so it is drawn to the negatively charged, damaged areas of hair and stays behind after rinsing. That is why conditioning happens where the wear is.
Solubility
Spreads through water without truly dissolving, and normal shampooing removes it.
Where it appears
Where it appears
One row per product category in our library: how many products list it, what share of that category that is, and where it typically sits on the label.
| Product type | How common | Typical position on label ? |
|---|---|---|
Conditioner
120 products
|
supporting · #6 | |
Leave-in
74 products
|
supporting · #6 | |
Mask / treatment
65 products
|
supporting · #7 | |
Co-wash
37 products
|
supporting · #6 | |
Styler: curl cream
9 products
|
supporting · #6 | |
Heat protectant
8 products
|
secondary · #15 | |
Shampoo
5 products
|
secondary · #12 | |
Styler: smoothing cream
5 products
|
supporting · #6 | |
Styler: gel
4 products
|
supporting · #6 | |
Finisher: serum
3 products
|
supporting · #7 |
8 more product types
| Product type | How common | Typical position on label ? |
|---|---|---|
Styler: mousse
2 products
|
supporting · #5 | |
Finisher: anti frizz finish
1 product
|
supporting · #8 | |
Finisher: end oil
1 product
|
supporting · #5 | |
Finisher: oil
1 product
|
secondary · #16 | |
Finisher: shine spray
1 product
|
supporting · #5 | |
Scalp treatment
1 product
|
secondary · #17 | |
Styler: hairspray
1 product
|
leading · #3 | |
Styler: lotion
1 product
|
supporting · #4 |
| Product type | Products | Share of category | Median position | Earliest position | Band |
|---|---|---|---|---|---|
| Conditioner | 120 | 17% | 6 | 2 | supporting |
| Leave-in | 74 | 18% | 6 | 2 | supporting |
| Mask / treatment | 65 | 17% | 7 | 2 | supporting |
| Co-wash | 37 | 38% | 6 | 1 | supporting |
| Styler: curl cream | 9 | 9% | 6 | 4 | supporting |
| Heat protectant | 8 | 6% | 15 | 3 | secondary |
| Shampoo | 5 | 1% | 12 | 5 | secondary |
| Styler: smoothing cream | 5 | 9% | 6 | 5 | supporting |
| Styler: gel | 4 | 3% | 6 | 5 | supporting |
| Finisher: serum | 3 | 4% | 7 | 6 | supporting |
| Styler: mousse | 2 | 1% | 5 | 2 | supporting |
| Finisher: anti frizz finish | 1 | 4% | 8 | 8 | supporting |
| Finisher: end oil | 1 | 11% | 5 | 5 | supporting |
| Finisher: oil | 1 | 1% | 16 | 16 | secondary |
| Finisher: shine spray | 1 | 2% | 5 | 5 | supporting |
| Scalp treatment | 1 | 1% | 17 | 17 | secondary |
| Styler: hairspray | 1 | 1% | 3 | 3 | leading |
| Styler: lotion | 1 | 8% | 4 | 4 | supporting |
No product-type differences have been researched yet — the reading below is computed from where it sits on the labels in our library.
Position footprint
Every listing in our library, by position on the label.
| Positions | Zone | Listings |
|---|---|---|
| 1-3 | Leading | 57 |
| 4-8 | Supporting | 187 |
| 9-15 | Secondary | 74 |
| 16-25 | Lower | 40 |
| 26+ | Trace | 20 |
How to read this
US labelling rules put ingredients above 1% in descending order of amount; below 1% they may be listed in any order.
So position tells you about relative amount only above that line, and we never convert a position into a percentage.
Who should pay attention
Conditional formulation guidance, scoped to a hair condition and to the positions where it is meaningful. It is not a conclusion about any finished product, and not a conclusion about you.
A C22 conditioning quat, the chain length that deposits most heavily in electrokinetic testing. It is the slip coarse or porous hair usually needs, delivered by chain length rather than by charge alone.
Read where it is listed in the first three ingredients, positions 4–8 or the lower half of the ordered list.A cationic conditioning agent: it binds to the damaged, negatively charged parts of the cuticle and lowers combing friction there.
The class that does the detangling in a conditioner. It deposits lubrication where the cuticle is worn.
Substantive by design. A routine with no detergent wash gives it nothing to leave with.
The heaviest-depositing of the conditioning quats. Near the top of a list that deposit is weight before it is smoothness, and fine hair registers it at the root first.
Read where it is listed in the first three ingredients or positions 4–8.Rows marked “researched” were read for this ingredient and cited below; the rest are read from its chemical class.
Why it matters to shoppers
What this ingredient is evidence of, what it is not evidence of, and what our own method can and cannot tell you.
- detangling
- thick or coarse hair
- detangling and less breakage from combing
- a stable cream that does not separate
- an exact safety score — we do not publish one, for any ingredient
- how a finished product performs by itself — that is the whole formula, not one line of it
- the exact percentage in a bottle — label position never converts into a number
- a supporting conditioner alongside the main ingredients in our conditioners
- it was on the label of every product we counted — we read printed ingredient lists, not marketing copy
- it is meant to stay on the hair rather than rinse away
- that a product is right or wrong for you
We do not publish safety scores or hazard grades. Where a regulator has published a restriction or a use condition, we state it and cite it; otherwise we describe what the ingredient does and stop.
Commonly paired with
Ingredients that appear alongside this one most often in our library. Near-universal ingredients are excluded — they pair with everything and tell you nothing.
- Cetyl Alcohol · 179
- Cetrimonium Chloride · 130
- Butyrospermum Parkii (Shea) Butter · 108
- Benzyl Alcohol · 102
- Cocos Nucifera (Coconut) Oil · 97
- Aloe Barbadensis Leaf Juice · 89
- Caprylyl Glycol · 86
- Guar Hydroxypropyltrimonium Chloride · 81
- Tocopherol · 80
- Stearamidopropyl Dimethylamine · 75
The number beside a name is how many products in our library list both.
These ingredients tend to appear together to soften the strand, improve feel after rinsing, and carry the formula and let it dry.
Found in these products
The most prominent placements first. The badge is the position on that product’s own ingredient list.
Nature Skin Shop · Co-wash
Co-Wash Clean Locks Cleansing Conditioner Bar
#1 on the label
Bounce Curl · Conditioner
Super Smooth Cream Conditioner
#2 on the label · $2.75/oz
Camille Rose · Leave-in
Curl Love Moisture Milk
#2 on the label · $1.58/oz
Camille Rose · Scalp treatment
The Gro Grease
#2 on the label · $2.17/oz
Color Wow · Leave-in
Dream Cocktail Coconut-Infused Leave-in Treatment
#2 on the label · $5.69/oz
Color Wow · Leave-in
Dream Cocktail Kale-Infused Leave-in Treatment
#2 on the label · $5.69/oz
Color Wow · Leave-in
Flo-etry Vital Natural Serum for Curly Hair
#2 on the label · $5.00/oz
Curls · Leave-in
Blueberry Bliss Reparative Leave In Conditioner
#2 on the label · $1.25/oz
Curls · Leave-in
So So Smooth Vitamin C Leave In Conditioner (Poppin Pineapple Collection)
#2 on the label · $2.49/oz
Davines · Leave-in
MINU Milk
#2 on the label · $6.51/oz
Jane Carter Solution · Conditioner
Nutrient Replenishing Conditioner
#2 on the label · $1.75/oz
Mielle · Leave-in
Pomegranate & Honey Leave-In Conditioner
#2 on the label · $1.17/oz
See all 339 products in the library that list Behentrimonium Methosulfate
Identity
What this entry is, and what our references call it.
Behentrimonium Methosulfate
- CAS 81646-13-1
- PubChem 157846
- emulsifier
- behentrimonium methosulfate
- behentrimonium methosulfate (and) cetearyl alcohol
For your hair?
Whether Behentrimonium Methosulfate matters for your hair depends on your hair.
the 7th most-listed conditioning agent in our libraryWhat this ingredient does, and where it sits on the labels we have researched.
A verdict on any product that contains it, and never a safety grade.
We do not physically test your hair. Everything above is read from the ingredient lists in our library and from published references — the consultation is what turns it into a plan.
References
Sourced Backed by a manufacturer or regulatory source.
This ingredient
- Manufacturer or regulatory International Journal of Cosmetic Science — Tham et al. (2026) measure adsorption by alkyl chain length and counterion; the C22 behentrimonium salts show the strongest deposition of the conditioner quats tested. · accessed 2026-08-30
- Manufacturer or regulatory PubChem — Compound identity: CID 157846, CAS 81646-13-1, C26H57NO4S · accessed 2026-08-28
How this page was made
- Every number above is counted from the ingredient lists in our own product library — 339 of 3889 researched products list this ingredient. Nothing on this page is written per ingredient.
- The dots are named levels read from an ingredient’s chemical class, charge, solubility, or where it sits on the labels we have — never a score.
- US labelling rules put ingredients above 1% in descending order of amount; below 1% they may be listed in any order. Position tells you about relative amount only above that line, and we never convert a position into a percentage.
- The prominence bands (leading, supporting, secondary) are the same ones the product pages use to read a single label, applied here to the median position across a category.
- We do not publish safety scores or hazard grades. Where a regulator has published a restriction or a use condition, we state it and cite it; otherwise we describe what the ingredient does and stop.
- Identifiers and references appear only when a published source is attached to this entry; where none is, the row is simply absent rather than filled in.
- This is cosmetic information, not medical advice, and nothing here diagnoses or treats a health condition.
- Entry last updated 2026-08-31. Product-page methodology: the product library.