"The average individual can typically go 2 to 3 days without shampooing their hair. However, if your hair is visibly oily, you may not want to wait that long," she says. "Usually, you can go longer without washing your hair when your hair is styled up, but no one should ever go more than 14 days."
Prolonged periods of not washing can cause cause buildup on the scalp, damaging hair and even impeding its ability to grow, Lamb said. Grime from dirt, oil and hair product can show up within four to six days for people with finer, straighter hair.
According to stylist Rosi Fernandez, director of Ananda Ferdi it is not advisable to go for more than a week without washing hair, as follicles become clogged and do not get oxygenated," she explains.
Going a long time without washing your hair can cause a buildup of a yeast-like fungus called Malassezia on your scalp. Over time, this leads to a layer of dead skin cells that shed from your head in the form of oily, yellow-ish dandruff flakes. Dandruff can also make your scalp red, scaly, and itchy.
Narrator: After six months to a year, all that gunk can clog up your hair follicles, which can prevent new hair from growing and, over time, ultimately lead to hair thinning or even hair loss. There's also a risk of your scalp getting infected from all the bacterial buildup.
After a year, he said, you'd have a build-up of skin stratum corneum, or dead skin on top of your skin. It includes a build-up of a protein our skin produces that has a funky odor to it. Bacteria also would accumulate on the skin, giving off a nasty smell when it mixes with our sweat.
The bottom line is that dirty hair does not grow faster than clean hair, so you might as well have a clean scalp and fresh hair. Your hair will look better, feel better, and be healthier as a result.
For the average person, every other day, or every 2 to 3 days, without washing is generally fine. “There is no blanket recommendation. If hair is visibly oily, scalp is itching, or there's flaking due to dirt,” those are signs it's time to shampoo, Goh says.
Generally, she says, "you should be showering, bathing or cleansing yourself every two to three days." Though, if you're working out or engaging in an activity where you are sweating a lot, you may have to shower more often. The biggest problem that may stem from not showering enough? The stink.
Rossi generally tells his patients they should wash their hair once or twice per week. But if you've had chemical treatments that can make your hair drier — such as bleach, perms or relaxers — you might want to wash it less than once weekly to avoid breaking or brittle hair or split ends, he said.
Washing your hair only once a week brings the benefits of natural oils into sharp relief. After all, many hair serums and treatments are meant to replicate the oils produced by the scalp, but excessive shampooing strips the hair of these valuable substances.
“I typically advise patients to keep to a standard hair washing schedule, whether it is three times per week, weekly or once per month, regardless of activity level,” she says.
"Shampooing is topical and hair growth is systemic, meaning that the act of not shampooing will not affect or prolong the growth phase of the hair growth cycle," she told me. Worse still, Kingsley suggests that abstaining from regular shampooing could actually do more harm than good.
The no-poo method involves forgoing shampoo containing detergents that strip your hair of its natural oils. Your hair won't smell, because you're still cleansing it. Research the best shampoo alternatives for you: water only, conditioner only, coconut oil, ACV and baking soda, or a no-poo product.
How often should you shower? While there is no ideal frequency, experts suggest that showering several times per week is plenty for most people (unless you are grimy, sweaty, or have other reasons to shower more often). Short showers (lasting three or four minutes) with a focus on the armpits and groin may suffice.
Water is effective at washing away dirt, dust, and other water-soluble debris from the hair and scalp without stripping the hair of this sebum. However, Mamelak notes that if there are other oils in the hair (from a haircare or styling product, for example), a good portion of these will be left behind as well.
Not washing the hair regularly with shampoo has certain advantages like cost and time saving, reduced exposure to chemicals, and less risk of hair damage. However, it may increase the risk of scalp irritation and infections due to the buildup of sebum, dirt, and sweat.
If you normally wash everyday, it'll take time to get used to washing it less. So start by going an extra day or two in between your normal washes. Rinse your hair with water in between shampoos and try to build up to once a week. When your hair adjusts you'll notice a dramatic difference.
The most common cause of smelly scalp is a buildup of skin cells, sweat and sebum (body oils). Smelly scalp can also result from: Bacteria: The mix of bacteria and sweat on your scalp can cause an unpleasant odor. Fungus: Fungus on your skin can lead to dandruff and a smelly scalp.
The bottom line is that dirty hair doesn't grow any faster than clean hair, so you may as well have a clean scalp and fresh tresses. Your strands will look better, feel better, and be healthier, too.
Washing the hair less often can help the scalp remain healthy, prevent itching and flaking, and keep the hair soft and shiny. People with very oily scalps may develop acne on the scalp or along the hairline and may need to wash their hair more frequently to keep their hair looking clean.
“Shampoo less and your hair will be more hydrated,” they said, which helps promote thickness. “Be sure to use sulfate-free products to preserve your hair's natural oils. (Their whole line of products is sulfate-free, should you be in the market.)