How Often You Should Wash Your Hair, According To A Trichologist

May 2, 2023

A question that any hairstylist or beauty expert knows all too well: How often should I really be washing my hair? It’s a valid question, as there are many competing answers to it depending on who you ask.

Some say you should never skip a wash day, and others espouse the benefits of going weeks between shampoos. So you might be wondering where you fall on this shampoo spectrum. 

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Experts and consumers alike struggle with this because there’s no exact equation that works for everyone all of the time. Our scalp and hair types have different needs—not to mention they are affected by the weather, what products you use, and your activity levels.

So instead of dishing out hard rules, it’s best to evaluate your hair situation based on a set of criteria. “It really just comes down to education: Learn about the different factors at play when it comes to your scalp and hair health, then you can adjust your behaviors based on that,” says certified trichologist Shab Reslan. Here, we outline what most affects your hair and scalp and explain what that means for you.

The very first place to start is your scalp. Much as there are different skin types, there are different scalp types. Some naturally produce more oil, some are drier, and some flake more. What’s more, just as your skin type can fluctuate over time, your scalp type isn’t stagnant either. So make a habit of checking in with your scalp.

“Literally go in there, part your hair at various points throughout your head, and look at your scalp: Is it red? Are the flakes? Do you see oily buildup? Make this a habit,” says Reslan. “The bottom line is you just have to pay attention to it. People don’t do this enough.”

The scalp is so important because if your scalp is showing signs of inflammation, it can lead to hair loss. “If buildup or irritation is really extreme, it can even pull the hair down because there’s so much inflammation around the hair follicle,” says board-certified dermatologist Adarsh Vijay Mudgil, M.D.

• If your scalp is dry: Over-shampooing or shampooing with too harsh of a product will cause dryness of the scalp and hair. A dry scalp usually feels tight, itchy, and might come with small, dry flakes—not to be confused with oily, yellow flakes that are a sign of buildup or psoriasis scabs. If you suspect this is your issue, wean yourself off your shampoo schedule. Start by skipping one wash day a week for a few weeks, and then skip another—do this until your scalp feels less irritated and your natural oils are balanced. 
• If your scalp has buildup: Buildup is going to be the most common sign of not shampooing enough. Buildup comes from conditioner that was not properly rinsed out, styling products, oil, dirt, and dead skin cells. If the buildup is severe, your scalp may end up feeling tender and sore. In this case, you should add an additional wash day or two a week. You should also consider doing a scalp scrub as a reset to really get the gunk out before you start your new schedule. 
• If you have dandruff: Fighting flakes from seborrheic dermatitis is more about what you shampoo with rather than how much you wash. (Read: Find a shampoo with antifungal properties to help you deal with the flakes, like these salicylic acid or tea tree shampoos.) However, the condition can worsen if you shampoo irregularly: “Shampoo more frequently because this helps to wash away yeast and dead skin cells,” says board-certified dermatologist Hadley King, M.D.

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After the scalp, your hair texture should be the second largest factor in your wash schedule. Broadly, those with straight hair will need to wash more, and those with curly or kinky hair will need to wash less. These aren’t exact (as the other factors on this list will tip the scale), but this is a good place to start. 

And if you don’t know what your hair type is? Try our three-minute hair-type quiz here.

• Straight: Because this hair type gets oily faster—it’s easy for sebum to travel from root to shaft—individuals with this hair type will need to shampoo more often. Try every other day, and opt for a shampoo that helps add volume. 
• Wavy to loose curls: Most stylists recommend two to three shampoo days a week, with the occasional deep clean or scrub. 
• Tight curls or kinks: Overall, these hair types are drier and more breakage-prone; those with this hair texture will want to limit putting strands under physical stress via washing. This gives your natural oils more time to condition the strands. This hair type should shampoo once or twice a week—and never use sulfates.

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For natural shampoo fans, this point will come into play far more. While we love the new wave of shampoos sans sulfates, it does mean you need to be more diligent when you wash your hair and perhaps add in a weekly deep clean.

“I love that these new shampoos are healthier for your hair, but the problem that many stylists are seeing now is that they are so gentle that people aren’t properly cleaning their scalps,” says Reslan. “If you want to stick with your low-lather shampoo, you absolutely should, but you might need to add in another wash day or do a weekly clarifying shampoo.” 

• Signs your shampoo isn’t strong enough: If you continually have buildup or your hair gets greasy right after you wash it, it might mean your shampoo isn’t working hard enough. No, this doesn’t mean you need to go buy a “traditional” shampoo—it just means you might need to add another wash day to your week to make up for it. Or you can use a natural clarifying shampoo once a week to blast away any leftover buildup that your daily shampoo cannot remove. 
• Signs your shampoo is too strong: If your product is too harsh for your needs, your scalp will likely feel irritated and your strands frizzy. (One recent study actually showed that frizz was the top indicator1 of an overly cleansing shampoo.) Simply switch to a low-lather shampoo. 

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• Silicones: These work so well because they grip onto your strand to seal down the cuticle2, creating the illusion of shiny, silky hair. They are found in many types of hair care and styling products but most notably in leave-in stylers. The problem? They don’t easily come off in the shower, especially the oil-soluble dimethicone3, so you end up piling on layer after layer, without effectively removing the layer before. Consider switching to silicone-free hair care. 
• Dry shampoo: Dry shampoo isn’t necessarily a problem on its own, but its overuse certainly is. Many people use them in place of wash, not as a temporary styling aid. If you are using dry shampoo, we recommend not letting it sit on your strands for more than two days. 

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If you build up a sweat every day (like cycling class or hot yoga levels of sweat), we understand that you’re probably going to want to wash it every day. That’s just being realistic.

“For many people like this, washing the hair every day is nonnegotiable: They just have to do it,” says Reslan. She recommends switching to a really gentle, moisturizing shampoo in this case. This likely means bringing your own shampoo to the gym or studio—don’t trust the generic shampoos they have in locker rooms, as they likely contain sulfates and cheap drying ingredients. Some days, you may even consider just rinsing your hair with water.