I’m not gonna lie, I think I hold a bit of resentment over my boyfriend’s 2-in-1 shampoo and conditioner bottle in our shower. I like to glare at it in frustration as I rinse three different hair care products down the drain every night before I spend another five minutes brushing out all the knots and tangles in my long hair once I step out of the tub. I envy my boyfriend’s super-quick shower routine, and sometimes fantasize about narrowing down my own hair care regimen to just a single bottle.
If you’ve also been thinking about making the switch to a 2-in-1 to save time, money, and sanity (or is that just me?), its useful to know how a 2-in-1 shampoo and conditioner actually works and who should be using it. Below, we’ve asked the experts to explain this double-duty invention.
What exactly is a 2-in-1 shampoo and conditioner?
A 2-in-1 shampoo is a product designed to give the cleaning benefits of shampoo while also providing some of the conditioning benefits of a conditioner. “Shampoos often contain anionic (negatively-charged) surfactants to cleanse, while conditioners contain cationic (positively-charged) ingredients like polyquats that will bind to hair to impart their conditioning properties,” explains cosmetic chemist Kelly Dobos. “Trying to combine these two incompatible types of ingredients in one formula can result in a gunky, unpleasant product. However, cosmetic chemists have developed unique ways to deliver conditioning ingredients from shampoos by optimizing ratios of these ingredients, or ‘hiding’ the conditioning agents and polymers in an emulsion that releases those ingredients when rinsing.” Conditioning shampoos are the subject of a lot of research in the industry with many, many patents issued, according to Dobos.
How do 2-in-1 shampoos and conditioners work?
Think of 2-in-1s as a shampoo that contains some of the conditioning benefits of a conditioner, rather than a true “best of both worlds” situation. Typically, two types of conditioning ingredients are “hidden” in this type of formula: silicones (like dimethicone) and cationic polymers (like polyquaternium-7). “When shampoo is diluted on hair, the micelles of the detergent break open and the silicone deposits on the hair,” explains cosmetic chemist Perry Romanowski. “Cationic polymers work similarly except they are not in the shampoo micelles. Rather, they are dissolved in the shampoo and then when the product is more diluted, they fall out of solution and plate on the hair.”
The benefits of 2-in-1 shampoo and conditioners.
The advantages of using a 2-in-1 are aplenty — first off, there’s the time-saving, one-stop-shop aspect of it all. “A 2-in-1 still moisturizes and cleanses your hair, but saves you time by not having to do the two separate steps in the shower,” says Jana Rago, a hairstylist and owner of Jana Rago Studios. “When you’re on the go showering at your gym or traveling, for example, bringing one bottle of 2-in-1 shampoo and conditioner not only saves you time showering but saves you precious space in your cosmetics bag.”
The second benefit of a 2-in-1 would be the sustainability aspect. Not only are you reducing the number of products you’re buying (meaning, theoretically, less plastic waste), but you’re also (again, theoretically) reducing water consumption in the shower by streamlining your routine, notes Dobos.