Photo by Eugenio Marongiu -- Getty Images
The word surfactant is a shortened form of "surface-active agent" and is a chemical that stabilizes mixtures of oil and water by reducing tension. Most think that their main objective is to remove dirt, excess sebum, and oil from the scalp and hair, but that is just one type of surfactant. All surfactants are not the same and behave differently. Some cleanse while others smooth the hair’s cuticle and create a smoother texture for soft curls.  

Surfactants can be divided into four groups, according to their ionic nature:

  • Anionic surfactants carry a negative charge when ionized and provide lather and detergency in the shampoo.  
  • Cationic surfactants carry a positive charge when ionized and are mostly used in conditioners, as they are not easily removed during the rinsing process and form the basis of conditioning. 
  • Nonionic surfactants have no charge to the molecule. According to Sister Scientist: “These types of surfactants are not ideal for cleansing, but are used primarily to modify the level of foam and aid in solubility. Cocamide MEA and coco glucoside are examples of this type of surfactant.”
  • Amphoteric surfactants carry both positive and negative charges when ionized. They are popular in shampoos now, as they are very useful for decreasing the irritancy while also increasing the active contents of the lather produced. They are mild and often used in baby shampoos. 

There is a negative perception about surfactants because they are mostly associated with sulfates. Sulfates are surfactants but not all surfactants are sulfates. We have broken down six well-known surfactants that not only nourish the hair but also make detangling easier.

Behentrimonium methosulfate

Naturally derived from rapeseed oil, this mild yet effective quaternary ammonium compound ingredient is known and appreciated for its detangling properties. This surfactant is often formulated in conditioners to smooth out the hair cuticles and condition them. Also acting as an emulsifier, behentrimonium methosulfate is gentle and can often be found in baby products and other lotions and creams for supple skin. Here are two curly hair products with behentrimonium methosulfate: Jessicurl Deep Conditioning Treatment and Blended Beauty's Curl Quenching Conditioner.

Behentrimonium chloride

A cationic quaternary ammonium compound made from canola oil, behentrimonium chloride is a cleaning/conditioning agent that will detangle, fight static, and soften strands. This plant-based surfactant deposits on the hair to provides potent conditioning effects with its waxy texture, which makes it ideal for defrizzing and emulsifying. Try these two products formulated with behentrimonium chloride: SheaMoisture Raw Shea Butter Restorative Conditioner and L'Oreal Paris EverSleek Sulfate-Free Smoothing System Smoothing Deep Conditioner.

Cetrimonium chloride

This cationic compound and conditioning agent is mainly used to prevent static and buildup in hair. It cleanses and eliminates odor by preventing the growth of microorganisms and enabling water to mix with dirt and rinse away. If found in conditioner, then you probably have a great co-wash. It can also be found in hair dye, shampoos, conditioners, styling gels, mousse, and detanglers. Check out these two products with cetrimonium chloride: Nioxin Scalp Therapy, System 4 Scalp Therapy Conditioner and Silicon MIX Intensive Hair Deep Treatment.

Dicetyldimonium chloride

Another cationic quaternary ammonium compound that is gentle but effective in cleaning hair and removing buildup. It is a hair conditioning, anti-static, emulsifying agent that is quite often found in co-washes. These two conditioners are formulated with dicetyldimonium chloride: Sta-Sof-Fro Rub On Hair & Scalp Conditioner with Special Softeners & Moisturizers and Tigi Catwalk Fashionista Conditioner Safe For Color.

Stearalkonium chloride

This ingredient is derived from stearic acid, a fatty acid found in plants and animals. It is extremely effective as a conditioner and softener with low eye irritation. It is also used in hair bleaches, rinses, setting lotions, and conditioners. It also adds luster to the hair. Here are these two products with stearalkonium chloride: Manic Panic Electric Yellow Cream Hair Color and Avlon KeraCare Humecto Crème Conditioner.

Cetrimonium bromide

Cetrimonium bromide is an emulsifier that prevents static buildup that causes flyaway hair. Really great for damaged hair, this ingredient is small enough to be absorbed into the damaged areas of the hair. Check out these two products with cetrimonium bromide: I.C.O.N. Respond Anti-Aging Conditioner and Burt's Bees Hair Repair Shea & Grapefruit Deep Conditioner.