The Detox shampoo claims to break down buildup without stripping the hair and scalp. It certainly gets the job done, but my hair wasn’t left feeling too “squeaky” or difficult to run my fingers through either. This is likely a result of an ingredient the brand doesn’t call out.
“To mitigate any potential of the hair being stripped the shampoo uses guar hydroxypropyltrimonium chloride which is a cationic polymer that helps the hair feel conditioned and smooth,” says Olu. “Hair has a net negative charge, so using positively charged ingredients such as [this one] helps to smooth the hair. In addition, the use of panthenol helps smooth the cuticle as well.”
The formula, Ko adds, includes a melange of surfactants that together, wind up delivering a gentle-yet-thorough cleanse. “Surfactants aren’t ‘smart’ though, so they’re not specifically targeting dirt and residue on the hair compared to components that they want to be left behind,” Ko explains. “Often, it’s just a gentler cleanse compared to a stronger one.” He says if you have a very dry scalp or very dry hair, though, Detox could leave behind a stripped feeling.
Speaking of surfactants, K18 promotes the use of “plant-derived” alternatives. Surfactants are a point of contention when it comes to formulations and marketing in the hair-care space, as they have been unfairly demonized as aggressive and harsh on skin. Both Ko and Olu note that technically, most surfactants are plant-derived. “Even sodium lauryl sulfate, which is subject to a lot of baseless fear-mongering, can be ‘plant-derived’ from coconut, or palm oil,” says Ko. “[But] it can also be made from petroleum oil.”
Olu warns against using the Detox shampoo if you have certain skin or scalp conditions because of the inclusion of salicylic acid. She suggests consulting your physician and/or dermatologist prior to using either shampoo if that’s the case. Overall, both chemists said the shampoos are suitable for all hair types. Ko even noted that there’s promising literature on the peptides that led to the development of K18.
“One of the papers in the literature looking at peptides, which led to the development of K18, was performed on African hair, some after chemical relaxing,” notes Ko. “They found some of the peptides were able to restore some of the hair’s tensile strength and elasticity. But it’s not clear if these exact peptides or concentrations are what’s in K18.”