What Is Co-Washing?

Co-washing is short for “conditioner-only washing.” It means skipping shampoo and relying solely on conditioner, whether you’re a daily or a weekly washer. Most conditioners contain trace amounts of detergents called cationic surfactants, or “quats” for short. (Some common types that you can find on your conditioner’s ingredient list are cetrimonium and behentrimonium chloride.) When mixed with water, the quats pick up tiny amounts of dirt, leaving unshampooed hair feeling clean, but not too clean (a common beauty mistake to avoid). At the same time, the conditioner contains, well, conditioners. “Since unshampooed hair retains more of its natural oils than shampooed hair, the conditioner’s moisturizing agents will now leave strands even smoother and silkier than usual,” says Nicole Tresch, a senior colorist at the Rita Hazan Salon in New York City.

Ideal Hair Types

Waves and Curls

Not sure if you should completely ditch your shampoo for conditioner-only cleansing? If your hair is dry, or it’s curly or wavy (both of which tend to be naturally dry), chances are you’ll benefit from co-washing. In fact, legions of ringleted women have been washing with conditioner alone for years. But what exactly are the benefits?

Color-Processed Hair

Assuming that they have healthy scalps, women with color-processed hair are also prime candidates for co-washing, as it allows them to go longer between salon treatments. “Co-washing doesn’t strip strands of pigment the way traditional cleansing can,” says Los Angeles hairstylist Jen Atkin.

Who Should Skip Co-Washing?

People with fine, straight hair should skip co-washing because their hair could get weighed down. Those with an oily scalp or dermatitis should steer clear, too. “Co-washing alone doesn’t effectively treat either condition,” says Jeannette Graf, MD, a New York City dermatologist. Stick with your regular shampoo-then-condition routine.

Choosing the Right Conditioner

If your hair is on the thicker side, the daily conditioner that’s already sitting in your shower may be all that you need. Just avoid conditioners with silicones, such as dimethicone, in the ingredient list. These are often added to conventional conditioners to smooth hair. But if you don’t shampoo daily, they can build up and weigh down your strands. If your hair isn’t as thick, you may do better with a product specifically designed for co-washing, called cleansing conditioners. These contain more cleanser than typical conditioners do but in the form of natural ingredients (like aloe vera), which remove grit more gently.

How to Co-Wash Hair

Eliminating shampoo from your hair-washing routine requires adjustments to how you rinse and condition your hair. Here are step-by-step directions for a smooth transition.