You're washing your hair wrong.
Or more accurately, washing your hair with shampoo is wrong. The concept of ditching shampoo has been drifting around the Internet since UGGs were still cool. This has given rise to dry shampoos, "no poo" routines, and weird DIY hair treatments that require you to pour powders and oils on your hair like it's ramen noodles.
But basically, it's ill-advised to wash your hair everyday like you do your body (hopefully?). As Julien Farel, French celebrity hair stylist and spa owner in NYC, says, "If you shampoo every day, it will strip your scalp of all its natural oils and can lead to dry, brittle hair." He and a growing legion of beauty bloggers argue that the body is a self-regulating machine; the more we interfere with our bodies' natural oil production, the more it tries to compensate. So if you're regularly stripping your scalp (which is still skin, after all, and so just as sensitive to harsh chemicals as the rest of your body) of its natural oils, it's going to start producing more and more oils in a cycle that results in limp, dry, or damaged hair and money wasted on shampoo that smells vaguely of hotel soap.
For alternative methods, take your pick. Some simply advise rinsing your hair with water and perhaps a gentle, fragrant essential oil. Some recommend rinsing with apple cider vinegar or baking soda. When it's time to give your hair a thorough cleanse, some urge you to do it as seldom as once every two months. Personally, Farel recommends his clients go a reasonable two to three days between shampoos, saying, "Only those with an oily scalp should wash every day."
And that's where it gets tricky—in that special way all beauty "tips" and "secrets" seem to get muddled between being an ancient elixir to eternal youth and beauty and just plain snake oil lies. If your hair hygiene should depend on your type of scalp, how do you know if you have an "oily" head? (Apparently, dandruff can be a common symptom of both a dry scalp and an excessively oily one). What if your scalp is naturally dry; should you never shampoo, then? What if your lifestyle is active and you often sweat, then shouldn't you definitely wash your hair with shampoo after work outs? Should your shampoo habits align with your Zodiac sign and the alignment of the moon? What is the moon made of, exactly? What really killed the dinosaurs? The mysteries are endless.
At least we know that there's no scientific evidence that shampooing regularly causes damage to your scalp or hair. Dr. Nicole Rogers is an assistant clinical professor of dermatology at Tulane University who told Health: "For the average person with healthy, untreated hair, there is no evidence that the simple act of shampooing, so long as it is with the appropriate ingredients for your hair, will cause damage."
Great, but what are "appropriate ingredients?" That truly does depend on your skin type. But generally, using cleansing conditioners, or co-wash, is a happy medium for everybody. For curly hair or sensitive skin, color treated hair or dry and frizzy strands, there's a cowash on the market that's suited to you. As Lush has taught us: If you can eat the ingredients, it's probably worth trying once (avocado conditioner, anyone?). Avoid silicone ingredients and seek out emollients (like shea butter or natural oils) and proteins (almond milk or soy). If you've used heavy oil or petroleum-based products on your hair recently, maybe opt for a shampoo or strong cleansing.
Above all, as with all skincare or health regimens, be smart about it. Please scrub your scalp thoroughly (it's skin; it gets dirty and clogged and smells if you don't). Remember to rinse thoroughly or you'll have hair like silly putty. Don't forget to detangle (and wet hair actually breaks much more easily than dry hair, so wait until it dries unless you have one of those brushes designed to work best with wet hair). Keep an eye on the moon cycle. Never forget the dinosaurs. Happy cleansing!