If your hair product shopping process involves walking into the drugstore blindly, buying any shampoo that meets your price and packaging preferences, and hoping for the best... well, you're doing it wrong. And more importantly, it could be causing breakage.
According to a new report from Johns Hopkins dermatologists, washing your hair correctly is one of the most important ways to treat acquired trichorrhexis nodosa (aka TN)—a common cause of hair loss and breakage. With the report, set to publish in the Journal of Dermatological Treatment, researchers hope they can help derms better advise patients when it comes to healthy hair care, and there are some pretty major takeaways that you should start implementing in your routine stat. (For more, see: 8 Ways You May Be Washing Your Hair Wrong.)
Step 1: Choose the right shampoo with the surfactants (active ingredients in most shampoos) that are best suited for you. There are three types of surfactants to look for when selecting a shampoo: anionic, amphoteric, and nonionic. Anionic surfactants are best for those with oily hair since they are effective at cleansing the hair, but they should be avoided if you have damaged or color-treated hair since they can leave strands feeling dry and prone to breakage. (As for what to look for on the bottle, the most commonly used anionics are sodium laureth sulphate and sodium lauryl sulphate, otherwise known as SLS and SLES.) The derms recommend opting for nonionic or amphoteric surfactants for those with natural black hair or dry, damaged, or color-treated hair, since these shampoos are gentler and less likely to strip the hair of moisture. (Look for 'coca' as in cocamidopropyl betaine or cocamidopropylamine oxide. We know—a mouthful!)
Another must is washing your hair at the ~right~ frequency for your hair type. "Patients with dry, damaged or tightly curled hair should limit their shampooing to no more than once per week. Those with straight hair, however, can shampoo daily," Crystal Aguh, M.D., assistant professor of dermatology at Johns Hopkins says in the release. That's because sebum has a harder time coating strands if you have tight curls, compared to straight strands, which can be easily coated, causing hair to look oily. (As a gal with stick straight strands: Thank the heavens for dry shampoo.)
Bottom line: How and when you cleanse your hair is super important for a healthy hair regimen, and not washing it enough can lead to a buildup of residue from your products, which can cause problems like seborrheic and irritant dermatitis (a red, itchy, flaky, rash on your scalp), she says. (Something to keep in mind over holiday vacation when you're prone to go on a shampooing hiatus!)
Of course, conditioning hair is also crucial since it helps to at least temporarily mend any damage to your hair shaft. But whether you should be using a rinse-out, deep, or leave-in version depends on the extent of your damage. For more damaged hair, derms recommend using a leave-in conditioner on a daily basis to protect from styling damage, and a protein-containing deep conditioner to help treat breakage and enhance moisture. Just be sure to only apply on a monthly or bimonthly basis to prevent brittleness. (Here, The Best Hair Products to Embrace Your Natural Locks.)
As for all your favorite oils, they're safe to keep in your arsenal, but make sure you're slathering them on correctly. To minimize breakage and treat or prevent TN, the researchers recommend applying coconut oil to strands before you shampoo and then again after you wash. They suggest the "soak-and-smear" method to up your hair's moisture retention: After shampooing and conditioning hair normally, lightly blot with a towel, apply a water-based leave-in conditioner, and then immediately apply your coconut, olive, or jojoba oil and let hair dry before you style.
The researchers also found that thermal styling tools like flat irons and blow-dryers, and chemical processing—whether through coloring hair or permanent straightening treatments—are all risk factors for TN since they damage the hair cuticle (the protective outer layer of the hair shaft), altering the hair's structure and leading to weak points prone to breakage. (These healthier hot tools and styling tips can help.)
Check out their handy infographic below for more tips on how to choose the right products for you.