Ingredient · Cationic Conditioner
Behentrimonium Methosulfate (BTMS)
INCI · Behentrimonium Methosulfate
Related names and forms: BTMS. This list does not indicate synonyms or exact ingredient matches.
Behentrimonium Methosulfate (INCI: Behentrimonium Methosulfate; commonly BTMS) is one of the most common cationic, positively charged ingredients in hair conditioners. It is a quaternary ammonium salt, usually produced from plant sources such as rapeseed or canola fatty alcohol. It works electrostatically: hair, especially areas damaged by washing, heat or colour, becomes negatively charged. BTMS's positive charge adheres to these surfaces, leaving a thin conditioning film. This provides slip, detangling, softness and reduced visible frizz without a heavy or greasy feel, allowing use on fine hair too. BTMS also acts as a cationic emulsifier, forming both the conditioning and consistency foundation of some creamy conditioners. It works well in low-pH systems and is compatible with humectants and proteins. Its lack of build-up for most users makes it a common conditioning choice. Labels show 'Behentrimonium Methosulfate'. Klaris considers it part of the conditioning system and overall formula, not a standalone softening promise.
i. Cosmetic Functions
Frequently Discussed Effects
The following headings summarise areas of effect frequently discussed in the literature; visible results in each area require regular use and a suitable formula.
Slip and Detangling
Leaves a thin, positively charged film on the strand, providing slip and easier combing.
Softness and Antistatic Effects
Gives a soft feel and softens visible frizz through reduced static.
A Lightweight Feel
Conditions without a heavy, greasy feel, allowing use on fine hair without flattening it.
Mechanism
What Happens Within the Skin?
The following points summarise mechanisms from dermocosmetic literature in plain English. Klaris presents them as background information to help readers understand the context, not as medical claims.
Step 1
Cationic, Positively Charged Film
Its positively charged quaternary ammonium structure adheres electrostatically to negatively charged, damaged strand surfaces.
Step 2
Slip and Detangling
A thin film on the strand provides easier combing, softness and an antistatic appearance.
Step 3
Emulsifying Properties
Also works as a cationic emulsifier, forming the consistency foundation of some creamy conditioners.
ii. Role in the Formula
How Is It Read on a Label?
BTMS is a quaternary ammonium salt, or quat. Its positive charge lets it adhere electrostatically to strand surfaces negatively charged by damage. It forms a conditioning foundation in rinse-out conditioners, leave-ins and masks, and also serves as a cationic emulsifier. It works well in low-pH systems and is compatible with humectants and proteins. Plant-derived rapeseed or canola versions are common.
Typical Concentration Range
1% - 7% (depending on product type)
Ingredient Family
Conditioning Ingredients
iii. Sensitivity Advisory
A Note on Extra Care in Context
Generally a lightweight, well-tolerated conditioner that does not build up for most users. Layering a very heavy conditioning routine at fine-hair roots can feel weighty; application focused on the ends is assessed in context.
A sensitivity advisory is not an instruction for use; where individual health circumstances, pregnancy or known sensitivities are involved, discussing the decision with your doctor may be a more contextual approach.
Scientific Basis
Sources and Their Scope
The following headings indicate areas of research; they are not citations of a specific publication or confirmation that every statement on this page has been verified. The links provided should be read with their individual scope in mind.
- International INCI / CosIng database
- Formulation chemistry guides
- Cosmetic ingredient safety assessment groups
Starting Points for Independent Research
These links lead to official databases and serve as starting points for searches.
iv. Related Ingredients
Ingredients Often Read Together
v. Conditioning Ingredients Family
Other Ingredients in the Same Family
Explore ingredients in the same functional family to deepen your reading of formulas.
vi. Academy · Related Reading
For a Closer Look
6 Min Read
How to Read an INCI List on a Hair Product
Familiar ingredient families in shampoo, conditioner and masks, and how the context of the same list changes with your Hair Identity.
6 Min Read
Curly Hair Care: How to Read the Ingredients
Curls change how moisture is distributed along the strand: humectant and emollient families, frizz tendencies and the context of washing.
6 Min Read
Fine and Thick Hair: How to Read the Ingredients
Strand thickness, tolerance for weight and the appearance of volume: key ingredient families for fine and thick strands.
Klaris · Example Analyses
How Does Behentrimonium Methosulfate (BTMS) Feature
in Your Products?
Explore product examples to see the ingredient list, general assessment and match score that changes with the example profile together.
Masked products and example profiles, not a personal analysis. Profile matching in the app is part of Klaris Premium. The app is currently available in Turkish. An English version is in preparation.