Your scalp and hair are more important than you think — and not just for social reasons. Improper care can lead to issues like itchiness and inflammation. The state of your hair can also offer a window into other conditions, like anemia or thyroid disease.
To prevent certain issues and catch other signs and symptoms, you want to make sure you’re caring for your hair to the best of your ability. That can feel like a big ask, even to someone who pays close attention to their crowning glory. One trip to the hair care aisle or a scroll down the ads on Instagram can bombard you with confusing terms and far-fetched claims. We asked doctors to weigh in on the best shampoo for your ‘do.
Shampoo 101
Shampoo is basically soap for your head. It cleanses the scalp and hair by removing unwanted oil, dirt and product buildup that water alone can’t. “The scalp is an extension of the body, and in that sense, it’s no different in terms of needing a cleanser,” says Los Angeles dermatologist Dr. Sanusi Umar, head of the UCLA Hair and Scalp Disorder Clinic. “If no shampoo is used, then debris, bacteria and oil can build up on the scalp and hair.”
But choosing a shampoo isn’t easy. “The marketing claims on shampoos and other hair products are very challenging for consumers to navigate,” says Dr. Erum Ilyas, a dermatologist in Philadelphia. “There’s not a ‘user manual’ to understand the claims.”
There are, however, some blanket rules about what ingredients you should steer clear of. Experts say to avoid shampoos that contain formaldehyde, phthalates, parabens, imidazolidinyl, toluene and alcohol. Frequency is another parameter to understand when shopping for hair products. If you have curly hair, a daily shampooing will likely wreck your look, no matter how much you condition after.
Sulfate-free shampoo
Sulfates are salts that help lift oil and other residue from hair shafts, allowing it to be rinsed out without leaving a film. Sulfates are also behind the soapy lather your shampoo creates. Many of the sulfates found in personal care products are derived from petroleum.
One reason you find sulfates in so many shampoos is that they’re great at cleaning hair.
But on the flip side, they can clean a little too harshly, stripping hair of its natural oils and leading to strands that are rough, frizzy and prone to tangling. Sulfates can also irritate your eyes, skin and lungs.
Sulfate-free shampoos won’t lather, but some experts say they’re better for certain hair types.
“Sulfate-free shampoos are beneficial to people who have sensitive skin, or those who have certain skin conditions, like rosacea,” says Dr. Anna Chacon, a Miami-based dermatologist. “They’re generally milder, so they’re best for color-treated hair, and also dry and frizzy hair.”
Some say sulfates aren’t as bad as the beauty industry claims. “Sulfates are something everyone loves to hate,” says Ilyas. “They’re strong and cheap, so they’re an easy thing to add to products to enhance their ability to clean. It’s true that they’re likely too strong for daily shampoo use, because they can leave hair feeling excessively stripped of natural oils, but they’ve been mislabeled as ‘bad.’”
Apple cider vinegar
Deserved or not, apple cider vinegar has achieved near-panacea status in the wellness world. When it comes to hair care, its proponents may actually be onto something. The ideal pH balance of hair is between 4 and 5, and many shampoos have a high pH, which can increase tangling and frizz.
In theory, an acid like apple cider vinegar can bring an alkaline environment into a more neutral pH, which marketing pros might call “restoring balance.” What’s more, ACV has demonstrated antimicrobial effects, which could help kill any fungus or bacteria that might be causing issues.
“Apple cider vinegar does contain high acidic content and antibacterial and antifungal properties, which may be helpful for conditions like dandruff or a scalp bacterial infection,” says Umar. “It also helps keep your hair in a state of acidity, which is good for hair.”
However, ACV contains acetic acids, which can burn your skin, so be sure to dilute it and avoid contact with your eyes.
Off-the-shelf dandruff shampoo
Dandruff, which causes the skin of the scalp to flake, is an eyesore. It has a number of causes, including dry skin, a yeast-like fungus and conditions like psoriasis and eczema.
Traditional dandruff shampoo can treat some dandruff caused by these conditions. These shampoos contain antimicrobial ingredients (ciclopirox and zinc pyrithione are biggies) to relieve itching and flaking, buildup and excess oil.
“If you have mild dandruff, an off-the-shelf shampoo may work just fine for you,” says Chacon. “These shampoos do have active ingredients, but in much lower concentrations compared to prescription-strength dandruff shampoos.”
Prescription shampoo
A doctor might prescribe a shampoo to treat more serious hair and scalp conditions, such as scalp psoriasis or extreme dandruff. It may contain the same active ingredients as off-the-shelf dandruff shampoo in higher concentrations, or other active ingredients only found in prescription products. “The three main types of prescription shampoos are antifungal, anti-inflammatory, and anti-scaling shampoos,” says Ilyas.
While these products are helpful for treating specific conditions, they can be damaging in the long term. “Due to their powerful ingredients, which can be harsh on the hair, prescription shampoos are usually prescribed for temporary use until a patient’s condition improves,” says Umar.
Clarifying shampoo
As the name suggests, clarifying shampoos are formulated to clear up residue that has accumulated on the scalp. To do this, they have higher concentrations of surfactants — a soap-like substance that includes sulfates — which help provide the deepest cleanse. “Clarifying shampoos have a much higher surfactant content than regular shampoo, so they do a better job of cleansing hair of excess oils and product buildup,” says Umar.
These shampoos can be great for getting rid of stuff that regular shampoo can’t, but they should be used sparingly, Umar says, or you risk stripping the hair of too much of its essential protective oils.
Shampoo for color-treated hair
Because of the way hair dyes bond to our hair, color-treated tresses need extra gentle cleansers. Ilyas explains that hair dyes work by opening up the hair follicle and depositing the artificial pigment inside the follicle, where it then enlarges so that it’s too big to come out on its own. If the pH of your hair changes, it causes the follicle to open up once again, letting the pigment out (and thus causing your color to fade). The goal of shampoo for color-treated hair, then, is to help your hair maintain its pH balance.
This means that shampoos for color-treated hair are free of harsh chemicals, especially sulfates. They may also contain color-protecting ingredients, like UV protection, and moisturizing ingredients that help rehydrate color-treated hair. Your hair doesn’t need to be dyed to benefit from a formula like that.