In the men's grooming guidebook, if there is such a thing, one section's inscription surely polarizes more than others — especially, say, washing your face or applying sunscreen, which are common sense parts of a proper hygiene routine. I'm talking about washing your hair; giving it the classic one-two punch: shampoo and conditioner.

Experts, officially so and self-proclaimed alike, are divided on how many days a week you should be washing your do. The hair-obsessed have come up with their own guidelines, too. With some washing their hair every morning and night and others skipping shampoo during every shower, subscribing to one tried and true rule seems impossible. And online resources aplenty muddy the most manageable bit of advice everyone and their mother seems afraid to mention: how often you wash your hair truly depends on too many criteria to say there's a single universal solution. There are, however, loose guidelines for most hair types and some scalp conditions.

  1. If you have fine-textured hair shampoo daily.

  2. If you have medium-textured hair, shampoo daily to every other day.

  3. If you have coarser hair or curly hair textures, leave no more than 3 days between shampoos.

    (Want to know which hair type you have? Put a single strand between two fingers. Is it there but you can't exactly feel it? That's thin. There and you can feel it? Medium. There and pronounced? Thick. Yes, this is an abbreviated test but you get the gist. Settling on wavy, curly or straight is a bit simpler.)

    prose hair care products
    Prose

    Anabel Kingsley, consultant trichologist at Philip Kingsley, is well aware of this seemingly endless debate. (A trichologist, for those that don't know, specializes in the care and upkeep of human hair and the scalp.) She also points out that those engaging in it should shift their focus from "hair washing" to "scalp cleaning," which she says is the primary goal when putting your hair under the showerhead.

    Shocking, right? Maybe not if you have a master's in men's grooming. But, for other guys, myself included, this is all useful information. And there's plenty of it. Kingsley offers answers to all of your pressing questions below.

    The Expert's Advice

    Wait a second. Shampoos aren't focused on hair?

    "The aim of the game when you shampoo is to clean your scalp, which is a living tissue. Any suds that run down through your strands will be enough to cleanse them. Shampoo cleanses the scalp removing dust, dirt, sebum and sweat. Conditioner is then used to moisturize the hair, smoothing the cuticle."

    How often should you shampoo?

    "Your scalp is your hair’s support system. Frequent shampooing keeps your scalp clean and healthy – which is really important to the health of your hair. I recommend people with fine-textured hair shampoo daily. This is because people with finer hair have more oil glands on their scalp, and their hair, therefore, becomes greasy faster. If you have medium-textured hair, try to shampoo daily to every other day. Ideally coarser and curly hair textures should leave no more than 3 days between shampoos.

    "However, it also depends on what you do to your hair after you wash it. If you have to heat style every time you shampoo, the damage from styling may outweigh the good of cleansing. It’s about finding a balance."

    man in shower washing hair
    Peter CadeGetty Images

    Can you shampoo too often?

    "Shampoos are formulated to effectively cleanse the scalp. That’s their intended purpose. So if it isn’t doing its job, it either isn’t a well-formulated shampoo or is not correct for your hair texture.

    "All shampoo that has been formulated correctly for your hair texture should be gentle enough for intended daily use. If it is stripping then it is either not well formulated or incorrect for your hair texture."

    What about the "no poo" method?

    Context: There's an entire subset of the hair-wearing population that believes modern shampoos are doing more damage than they are good. Kingsley and I don't necessarily agree with a 360-degree ban on hair cleaning products, but there is validity to avoiding certain chemical compounds in the most common shampoos. (See: SLES, SLS, parabens, sodium chloride, alcohols, and a whole list of others.) It's not that shampoos are inherently bad, but rather not gentle enough.

    "If you don’t cleanse your scalp frequently excess oils, dirt, pollution and dead skin cells are allowed to build up. This can result in pores on your scalp becoming clogged and can lead to the formation of pimples. An accumulation of dead skin cells can also cause itching and irritation and visible flakes, while excess levels of oils on your scalp can throw off your scalp’s microbiome."

    philip kingsley shampoo
    Philip Kingsley

    Should you wash with hot or cold water?

    "Use warm water when rinsing. Cold rinses may be invigorating, but they do not make your hair shinier. Nor do they close the hair cuticle; conditioner does this. Cold water constricts the blood capillaries in your scalp, which carry vital hair-growth nutrients to each follicle, so it can have a negative impact on your hair."

    What should people with dry scalps do?

    "A true dry scalp is actually very rare and is more often than not, dandruff. Dandruff occurs when the microbiome of their scalp becomes imbalanced. Yeasts naturally live on our scalps, and usually do not cause any problems. However, when a certain species of yeast called the Malassezia yeasts overgrow, this can cause skin cells to divide too rapidly – leading to tell-tale flakes and itching. Malassezia yeasts thrive in an oily environment, and so are likely to overgrow if you shampoo infrequently or have a naturally oily scalp."

    Should you wash product out every time you use it?

    "Product can also build up on the hair and often shampooing alone is not enough to cut through and reveal the hair natural radiance and shine. [Vitamin C] dissolves away impurities on and below the surface of the hair’s cuticle for cleaner, more weightless hair."

    Shelve your usual shampoo. Get a gentler one.

    Philip Kingsley
    No Scent No Colour Gentle Shampoo
    Philip Kingsley Philip Kingsley
    $31.00

    Ulta
    Daily Shampoo
    American Crew Ulta
    $27.00
    Kiehl's
    Grooming Solutions Nourishing Shampoo + Conditioner
    Kiehl's Kiehl's
    $32.00
    Malin + Goetz
    Gentle Hydrating Shampoo
    Malin + Goetz Malin + Goetz
    $26.00
    Colorless Gentle Purifying Shampoo
    Horace Mr Porter
    $14.00
    Prose
    Custom Shampoo
    Prose Prose
    $25.00
    Nordstrom
    Gentle Shampoo
    Acqua di Parma Nordstrom
    $55.00