How Often Should You Wash Your Hair?
If you shampoo daily, you may be doing more harm than good for your locks. Our experts give you the skinny on exactly how often you should wash your hair.
You wake up, jump in the shower, and lather up your hair. That’s your morning routine and has been for as long as you can remember. But it turns out you may be doing more harm than good by shampooing your precious locks daily. (Yes, even if you’re using one of the best shampoos.) So how often should you wash your hair?
It seems like a simple question, but there’s no one-size-fits-all answer. Many of us are overdoing it, causing hair loss or breakage. Others are underdoing it, leading to flakes and oil buildup, says Amy McMichael, MD, professor and chair of dermatology at Wake Forest School of Medicine in Winston-Salem, North Carolina. “Generally, the hair and scalp should be washed at least weekly to every other week,” she says. But as with all rules, there are some exceptions.
Read on to find out just how often you should be hitting the (shampoo) bottle, based on your hair type. Then stock up on supplies, whether that’s the best shampoo for oily hair, the best shampoo for curly hair, the best shampoo for thinning hair, the best shampoo for color-treated hair, or purple shampoo for blondes. Throw in hair masks (like this K18 leave-in hair mask) and the best conditioners for good measure, and you’ll have clean, healthy-looking hair in no time.
What is shampoo exactly?
Shampoos typically contain several ingredients to help remove oil, dirt, dead skin cells, and other impurities, explains Janiene Luke, MD, an associate professor of dermatology at Loma Linda University in Loma Linda, California, and a member of the Skin of Color Society’s board of directors.
“Common cleansing agents, such as surfactants, bind these impurities and create a structure that can be easily rinsed away with water,” she explains. Common surfactants in shampoo include sodium laureth sulfate, ammonium laureth sulfate, sodium lauryl sulfate, and ammonium lauryl sulfate.
What else is in the bottle? Water, for one. Without adequate water, the shampoo wouldn’t be able to pour out of the bottle. Foaming or lathering agents like cocamide or cocamidopropyl betaine give your shampoo that satisfying sudsy factor. Shampoo also contains silicones like simethicone, which smooth and shine your hair. Other ingredients, like panthenol, fatty alcohols, and nut oils, are added to lock in moisture and hydration. Polyquaternium may be added as a thickening agent. And finally, there are the preservatives. These are added to make sure your shampoo has a decent shelf life.
How often should you wash your hair?
Ready to suds up? Your lifestyle will help determine how often you should wash your hair. “Those who exercise or perspire profusely for any reason may wash their hair more frequently,” says Dr. McMichael.
Your hair’s oil level will also play a role. If you have extremely oily hair, washing daily can keep your strands from looking greasy, says Dr. McMichael. On the flip side, “for those who have particularly dry hair shafts, washing infrequently may be helpful,” she says. (Your hair shaft is the part of your hair that can be seen above your scalp.)
How does hair texture play a role?
The texture of your hair makes a difference in how oily your hair gets each day. The oilier your hair, the more often you need to wash it.
So the first step is determining what type of hair you have. This is based on the amount of curl in your hair. It may be straight (no curl), wavy, curly or even super curly, or coily. The curl factor comes down to the shape of your hair follicles. If they are oval or asymmetrical, your hair will be curlier.
Still not sure what your hair type is? Ask your stylist next time you get a trim.
Naturally curly or textured hair
This type of hair tends to be drier because the sebum, or oil, does not travel as far down the hair shaft of a curly hair compared to a straight hair. So how often should you wash your hair if it’s curly or textured? At least weekly or every two weeks, Dr. McMichael says. The idea that everyone should suds up daily is just a hair myth.
Straight and fine hair
You may need to wash multiple times a week for the most effective hair styling, Dr. McMichael says. That’s because straight and fine hair tends to get oily faster than other hair textures. Wash infrequently—one of the biggest fine hair mistakes—and your locks might look greasy.
How often should you wash your hair with braids, locks, or weaves?
To prolong your style, you might avoid washing your hair for up to four to eight weeks. “This is too long to wait between washes, and a way to wash the scalp should be instituted even if it means the hairstyle is a bit mussed,” Dr. McMichael says.
She offers this tip for regular hair-washing: “Wash the scalp primarily and allow the shampoo to just run through the hair shafts to minimize further drying of the hair shafts.”
How often should you wash long hair?
Like those with curly hair, people with really long hair may experience dry ends since the sebum may not travel the entire length of the hair shaft, says Dr. Luke. “Shampooing is related to cleansing the scalp, so the length of the hair does not affect how often it should be washed,” she says. Instead, go by whether your hair is oily or dry.
How often should you wash with a scalp disorder?
If you have a condition like scalp psoriasis or seborrheic dermatitis (aka dandruff), you may need to wash your scalp with medicated shampoo several times per week, Dr. McMichael says. “I typically recommend concentrating shampoos on the scalp itself—especially [for] those who use medicated shampoos, because some can be drying or strip the hair—and then follow up by using a good conditioner for the rest of the hair.”
How do you know which shampoo to use?
Oscar Wong/Getty Images
Your choice in shampoo matters because it’s part of your larger hair-care practice. A shampoo that doesn’t weigh down your fine, thin hair may extend the time between washings. Medicated shampoos may require a certain number of uses per week.
You’re probably wondering, “How do I know which shampoo to use?” Here’s a hair stylist tip: Use a shampoo that has high-quality surfactants. This will make a big difference in the look and feel of your locks. “The less abrasive your surfactants are, the more moisture will stay in your hair,” says Michael Dueñas, an Aloxxi celebrity hairstylist based in Los Angeles.
Abrasive surfactants like sodium lauryl sulfate strip your hair of moisture, Dueñas explains. And that can lead to breakage, especially if you’re washing your damaged hair too often.
“Using a moisture shampoo is always a bonus,” he says. “If the surfactant is a variation of sodium laureth sulfate or sodium lauryl ether sulfate or a coconut derivative, you are in good hands.” Sodium lauryl ether sulfate is gentler than sodium laureth sulfate, he says.
Another great product to consider is a deep conditioner, which can offset some of the damage and keep hair looking healthy, Dr. Luke says.
To be effective, your shampoo also has to have the perfect pH level, which means it needs an acidic ingredient like sodium citrate or citric acid. A quick chemistry refresher: The pH scale ranges from zero to 14, with 7 being “neutral.” The lower numbers are more acidic, and the higher numbers are alkaline.
Why should you care about your shampoo’s pH? It can affect your hair health. If your shampoo has an alkaline pH, for instance, it can cause cuticle damage and hair breakage, according to research in a 2014 issue of the International Journal of Trichology. Pro tip: If your hair is prone to frizzing, choose a low-pH shampoo (it’ll say “pH balanced” on the label).
Can you use dry shampoo instead of washing?
No. Dry shampoo may be trendy, but it doesn’t work the same way as liquid shampoo, Dr. Luke says. “It has ingredients that help absorb excess oil on the scalp,” she says. “They do not cleanse the scalp or remove the dirt or oil.
It’s a good call in a pinch if you are between washes, but it’s not a substitute for shampoo, she warns.
McMichael agrees. “Dry shampoos are best used to prolong washing by a few days at most or quickly allow better appearance of hair shafts when they are oily,” she says.
Is it unhealthy to wash your hair every day?
It can be. “If you are washing your hair multiple times a week, that in and of itself may not cause damage,” says Dr. Luke. But if you always use high-heat styling tools after you wash, and you wash it daily, it may cause cumulative damage to the hair, including dry hair and breakage.
If you are experiencing hair loss and shedding, more-frequent manipulation from over-shampooing or styling may lead to more noticeable shedding, she says.
So, how often should you wash your hair? It’s a fine balance. If you don’t wash your hair enough, you can also run into problems. “You may experience buildup or flaking,” says Dr. Luke.
Getting it right may involve some trial and error, adds Dueñas. “If your hair seems to get greasier quicker with more washing, then you need to do less,” he says. “If your hair is naturally greasy, then you may need to wash slightly more.”
- Amy McMichael, MD, professor and chair of dermatology at Wake Forest School of Medicine in Winston-Salem, North Carolina
- Janiene Luke, MD, associate professor of dermatology at Loma Linda University in Loma Linda, California, and a member of the Skin of Color Society’s board of directors
- International Journal of Trichology: “The Shampoo pH can Affect the Hair: Myth or Reality?”
- Michael Dueñas, Aloxxi Celebrity Hairstylist based in Los Angeles