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What Are Surfactants and Why Are They Used in Haircare?

BY Laura Casciola

Sulfate-free surfactants that are gentle and still lather?! Let’s talk about them.

Surfactants are molecular compounds that act as cleansing agents in shampoos and conditioning agents in (you guessed it) conditioners. They are the cleaning part of wash day– without surfactants, you wouldn’t cleanse your hair at all when using shampoo. We’re here to tell you all about surfactants, why they’re used in hair care, and how we, at Function, use them safely and purposefully. Let’s start with the breakdown between cleansing and conditioning surfactants.

Cleansing surfactants

These short, negatively-charged surfactants are cleansing agents in shampoos that help get rid of dirt, oil, and residues on hair. They do so by picking up built-up oil and product from your hair and combining them with water from the shower, forcing the particles to detach from the hair shaft and leave your hair. Cleansing surfactants have a negative charge which creates a slight lift in the hair cuticle (why your hair might look bigger or have more volume after washing). 

Conditioning surfactants

These longer, positively-charged surfactants are conditioning agents that provide hydration to the hair. Their positive charge helps correct the negative charge of shampoo and smooths the cuticle back down (why your hair might feel smoothed out after applying conditioner). The positive charge also attracts the negative charge of hair strands and helps enhance their softness. 

Now that you have a basic understanding of surfactants and why they’re in hair care, let’s talk about the kind we use at Function, specifically. You might be thinking, “there are more kinds of surfactants than just positively charged and negatively charged?” Yes!  There are three levels of surfactants based on strength; these are listed from most-stripping to least-stripping:

  • Anionic surfactants- strong cleansing agents that create lather but can cause irritation. The most intense of these are sulfates

  • Amphoteric surfactants – mild cleansing agents and produce very little lather

  • Cationic surfactants – conditioning agents

Sulfate surfactants have been the workhorse of surfactant systems used in beauty for decades– they’re cheap and efficient cleaners. But over time, as the industry has been more safety-focused and as technology has improved, surfactants have become continually modified to become milder and safer. Now, sulfate-free surfactants are changing the industry with their mild and effective cleansing.

Our sulfate-free surfactants

Our Research + Development team told us, “choosing what kind of surfactant to use or how to balance a combination of them safely is what’s most important!” At Function, we pride ourselves on only using sulfate-free, amphoteric surfactants. These milder compounds are actually found in baby shampoos and body washes, and prioritize keeping the hair safe from harsh cleansers that could rip natural oils or layers of the hair and avoid any possible irritation. They’re also safe and mild on the skin. 

But don’t be fooled– mild doesn’t mean weak. Our surfactants are still extremely effective at cleansing the hair and scalp– we use a blend of anionic, amphoteric, and nonionic surfactants and a natural-based polymer to boost lather while keeping the formula gentle. Not only are they non-irritating, but they also cleanse without drying out the hair and are especially helpful for those looking to preserve color-treated hair.