With the level of gossip, half-truths, and misinformation swirling about something as simple as shampoo, you’d think we were dealing with a messy celebrity divorce. Is it making you lose your hair? Is it wrecking your color? Is it getting back together with Brad?! Respectively: Maybe, possibly, and you’ll have to ask him.

The Myth #1: Dry shampoo and cleansing conditioners can make your hair fall out.

The True Story: The Internet says dry shampoo can clog hair follicles on your scalp and make you lose your hair (but it also says Beyoncé was replaced by a clone, and, come on, no clone can dance like Bey). “Dry shampoos use powder, starch, or talc to soak up oil, and none of those ingredients directly impact the ability of follicles to grow new hair,” says Paradi Mirmirani, a dermatologist in Vallejo, California. But that doesn’t mean you want dry shampoo—or any other styling product—sitting around on your scalp for days (it could make you itchy). Aim dry shampoo right above the roots of your hair, rather than directly onto the scalp, advises cosmetic chemist Joseph Cincotta.

The truth about cleansing conditioners and co-washes, however, isn’t as clear-cut. Even the cosmetic chemists we talked to didn’t agree on whether or not their ingredients—which can include conditioning polymers but usually do not contain detergents—contribute to thinning hair. And the FDA is currently investigating the ingredients in one line of cleansing conditioners, from Wen. Last year, the company began a process to settle a class- action lawsuit from customers claiming its cleansing conditioners made their hair thin and fall out. Until we have more answers: Wash your hair with shampoo (the kind that sudses up) at least once a week to get rid of residue from products and cleansing conditioners.

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The Myth #2: The bottle should say "pH-balanced."

The True Story: It’s important that your shampoo be pH-balanced, which explains why they all are. Shampoos hover in a nonthreatening range of five to seven. “If hair’s pH gets above a ten or so, the fiber swells, and it will cause irreversible damage,” says cosmetic chemist Randy Schueller. “Coloring and perming processes utilize pH levels this high, but shampoos haven’t since the ’40s.”

The Myth #3: If it's good for skin, it's good for hair.

The True Story: Vitamins, hyaluronic acid—skin-care ingredients in shampoo sound awesome in theory, but that’s it. “Take hyaluronic acid,” says Schueller. “It’s a good hydrating ingredient for skin, but there are no proven benefits for hair.” What’s more, you rinse out shampoo. “They really can’t leave behind any of those active ingredients,” says Cincotta. “They’re going to go down the drain.

The Myth #4: It's healthier not to shampoo.

The True Story: Shampoos remove some of your hair’s natural oils (which moisturize and smooth frizz), but oils aren’t all that’s settling on your scalp during the day. “Your body is constantly exfoliating, so your scalp is covered in dead skin cells, plus bacteria, yeast, excess oils, and pollutants,” says Cincotta. Leaving those things sitting around for more than a few days could cause irritation, itchiness, or flakes (new research shows pollutants are especially irritating). And then there’s the issue of styling products—hair spray, mousse, you name it—with ingredients that stick to hair. If you don’t wash them off, they’ll make hair stiffer and more likely to break when you brush. In short: Shampooing is nonnegotiable, and it’s OK to wash your hair daily. If your scalp is itchy or tight—or if you have eczema or dandruff—scale back to once a week.

The Myth #5: Sulfate-free shampoo is better for colored hair.

The True Story: If you dye your hair (so...if you’re a woman over 16?), you’ve probably been told to use sulfate-free shampoos to avoid stripping your color. "I’ve tested sulfates against other surfactants, and I didn’t see a difference in terms of fading color,” says Schueller, adding that water is as damaging as any cleanser. "When your hair gets wet, it swells, the hair shaft opens, and some color leaches out.” Sulfates have been shown to be irritating to eyes and skin in some studies, but just because a shampoo is sulfate-free, that doesn’t mean it’s less likely to irritate: "Many sulfate-free shampoos that still lather have other detergents in them,” says Mirmirani. If you have a sensitive scalp, look for ingredients that include the words “isothionate,” “taurate,” or “decyl glucoside,” and avoid C14-16 olefin sulfonate. “I notice it in sulfate-free shampoos, but it’s just as intense as any sulfate,” says Cincotta. (Try ColorProof CrazySmooth Anti-Frizz Shampoo.)