How Often Should You Wash Your Hair? Here’s What Happens When You Don’t Get It Right

Updated: Nov. 17, 2023

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?

There isn’t a one-size-fits-all answer. But, according to dermatologists, stylists and other hair experts, many of us aren’t hitting the right number. And that can lead to bad hair days, at best, and hair damage and potential infections, at worst. Read on to find out just how often you should be hitting the (shampoo) bottle, based on your hair type and lifestyle.

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What’s in 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 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, such as 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, which are added to make sure your shampoo has a decent shelf life.

How often should you wash your hair?

Depending on your hair type and activity level, it could be anywhere from once a day to once every two weeks. But two weeks should be the maximum time between washes to keep your scalp healthy, says Amy McMichael, MD, chair of dermatology at Wake Forest School of Medicine in Winston-Salem, North Carolina. “[The right amount of washing] is most important when there are scalp issues,” she says, “but normal washing is very important to keep the scalp microbiome in check and the oils of the scalp at bay and to minimize possible dandruff or irritation.”

If you have extremely oily hair, washing daily can keep your strands from looking greasy, says Dr. McMichael. On the flip side, washing infrequently may be helpful for those who have particularly dry hair. Your lifestyle will also help determine how often you should wash your hair. “Those who exercise or perspire profusely for any reason may want to wash their hair more frequently,” says Dr. McMichael.

How does hair texture play a role?

How Often Should You Wash Your Hair

The texture of your hair makes a difference in how oily it gets each day. The oilier your hair, the more often you need to wash it.

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, wavy, curly, 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 and likely drier. Still not sure what your hair type is? Ask your stylist next time you get color or a cut.

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 with 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 a hair myth.

Straight and fine hair

You may need to wash multiple times a week for the most effective hairstyling, Dr. McMichael says. That’s because straight and fine hair tends to get oilier faster than other hair textures. If you wash infrequently—one of the biggest fine hair mistakes—your locks might look greasy.

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 explains. Instead, go by whether your hair is oily or dry.

How often should you wash color-treated hair?

Wash color-treated hair as infrequently as possible, says Zoe Diana Draelos, MD, a consulting professor of dermatology at Duke University School of Medicine in Durham, North Carolina. “Water, which is necessary for washing, allows the newly created color molecules from permanently dyed hair to diffuse out of the hair shaft,” she explains. “Every time you wash your hair, more of the hair dye is removed. So by washing less frequently, you prolong the life of your hair color.”

How often should you wash chemically straightened hair?

woman washing long brown hair with a shampoo barLourdes Balduque/Getty Images

Less is more with chemically straightened hair too. “Heat straightening breaks the hydrogen bonds in the hair,” Dr. Draelos says. “When you expose the hair to water, the bonds resume their normal conformation, and the hair is no longer straight.”

Some hair treatments require that hair only be washed once per week, while others allow hair to be washed two to three times per week, adds Gary Goldenberg, MD, a New York City–based dermatologist. “Hair should be washed less often immediately after the treatment.”

How often should you wash hair with braids, locs or weaves?

To prolong your style, you might think about going four to eight weeks between washes—but this is a mistake. “This is too long to wait between washes,” Dr. McMichael says. “A way to wash the scalp should be instituted even if it means the hairstyle is a bit mussed.”

She offers this tip for regular hair-washing if you have any of these styles: “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 if you have 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. “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,” says Dr. McMichael.

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 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 adds.

How long is too long to go between washes?

There is no drop-dead time range. It depends on how much sebum you make, which goes back to your hair type and lifestyle. “Oily scalps make more sebum, which means you need to wash more frequently,” Dr. Draelos says.

This is different than the no-poo method, which has been gaining popularity. “No poo means no suds,” explains Dr. Draelos. “A shampoo does not need to foam to cleanse.” Shampoos contain foaming agents to make suds. “People like foam, but it is not necessary, and no-poo shampoos work quite well.” No-poo can also mean you clean your hair with water or shampoo alternatives such as coconut oil, baking soda or apple cider vinegar.

What happens if you don’t wash your hair frequently enough?

Itching Dry Head Scalp And Long HairAndreyPopov/Getty Images

Not washing your hair frequently enough isn’t quite as problematic as not washing your face enough, but it eventually leads to oil and debris buildup, says New York City dermatologist Jessica Weiser, MD, the founder and medical director of Weiser Skin MD and an assistant clinical professor of dermatology at Columbia University in New York City. And once that happens, you may also experience the following issues.


Dandruff, or seborrheic dermatitis, is thought to be a reaction to a yeast that lives on everyone’s scalp and skin. “Some simply react to it and produce inflammation that leads to flaking,” Dr. Goldenberg explains. “And some things make it worse, such as harsh chemical treatments and shampoos, stress and poor diet.” Frequent washing with a regular shampoo is the best way to get rid of dandruff.

Hair loss

Not washing your hair enough can cause dirt, oil and product to build up, resulting in an oily, itchy and irritated scalp. “Itching can cause inflammation and lead to hair loss,” says Shilpi Khetarpal, MD, a dermatologist at the Cleveland Clinic in Ohio. Inflamed hair follicles (folliculitis) can also cause the scalp to itch and result in hair loss.

Bacteria or yeast buildup

If the thought of bacteria and yeast proliferating on your scalp wasn’t bad enough, your head may also start to stink. “Dirt, bacteria and the overproduction of sebum or oil can cause an unpleasant odor from an overgrowth of yeast,” Dr. Khetarpal says. If you don’t wash your hair for a while, oils that your scalp produces naturally accumulate around your hair shaft and can cause a yeast infection on your scalp. Caused by a yeast called Candida, it’s marked by an itchy, flaky rash.


Not washing your hair enough can also cause acne, Dr. Khetarpal says. “Oil and sebum can build up on your pillowcase, and if you don’t wash your pillowcase regularly, it can cause acne where your face touches it. It can also cause folliculitis, which occurs when hair follicles become inflamed and may look like small pimples.

Greasy hair

If you don’t wash your hair often enough, it starts to look greasy and slick. While this may make your hair easier to style at first, depending on your hair type, it will eventually cause hair to look limp and less than lustrous.

How do you know which shampoo to use?

shopping for shampoo at the store and holding shampoo bottle in hand to read the labelOscar Wong/getty images

In addition to how often you should wash your hair, your choice of shampoo matters because it’s part of your larger hair-care practice. A shampoo that doesn’t weigh down your fine, thin hair, for example, 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 hairstylist 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.

Gentler ingredients

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, FYI.)

Another great product to consider is a deep conditioner, which can offset some of the damage and keep hair looking healthy, Dr. Luke says.

Balanced pH

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 0 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 will say “pH balanced” on the label.)

Can you use dry shampoo instead of washing?

woman spraying dry shampoo in a camper vanMystockimages/getty images

No. Dry shampoo may be trendy, but it doesn’t work the same way as liquid shampoo. “It has ingredients that help absorb excess oil on the scalp,” Dr. Luke explains. “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.

Dr. 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.

What should you do between washes?

According to Dr. Weiser, you should avoid using excessive amounts of dry shampoo and other products that can worsen buildup, clog hair follicles and reduce natural oil secretions. “In between washes,” she adds, “scalp massage can help improve blood flow to the scalp to help bring oxygen to the hair follicles and scalp while also helping to detoxify.”

About the experts

  • Janiene Luke, MD, is an associate professor of dermatology at Loma Linda University in Loma Linda, California. She specializes in treating hair disorders.
  • Amy McMichael, MD, is a professor and the chair of dermatology at Wake Forest School of Medicine in Winston-Salem, North Carolina. She is the co-editor of Hair Diseases: Medical, Surgical, and Cosmetic Treatments.
  • Zoe Diana Draelos, MD, is a consulting professor of dermatology at Duke University School of Medicine, Durham, North Carolina. She is the author of 14 books, including Cosmetics in Dermatology and Hair Cosmetics.
  • Gary Goldenberg, MD, is a medical and cosmetic dermatologist and an assistant clinical professor of dermatology at the Icahn School of Medicine at Mount Sinai Hospital in New York City.
  • Jessica Weiser, MD, is the founder and medical director of Weiser Skin MD and an assistant clinical professor of dermatology at Columbia University in New York City.
  • Shilpi Khetarpal, MD, is a dermatologist at the Cleveland Clinic in Ohio who specializes in hair.
  • Michael Dueñas is an Aloxxi celebrity hairstylist based in Los Angeles. He specializes in cutting and styling curly hair.