Can You Actually “Train” Your Hair To Go Longer Between Washes? Here's What The Science Says

Greasy hair is the biggest enemy of a perfectly polished look, which is why we've all found different ways to deal with it. From washing our hair twice a day to using generous amounts of dry shampoo to hiding the grease with hats and headbands to using our natural oil to style our hair in slicked back buns, we've tried it all.

But have you ever heard of "training" your hair to go longer between washes? Be it from an influencer on TikTok or someone we know in real life who swears they only wash their hair once a week, this idea relies on the belief that our hair can get used to producing less oil the more infrequently it is washed and hence stay cleaner for longer.

Now, while the truth is a little more complicated than a simple yes or no, below, we will explain how our body's oil production affects our hair and whether "training" our hair to last longer between washes is actually a practice supported by science.

Why Does Hair Get Greasy?

The short answer: oil production. But let’s break it down a little more. The scalp naturally produces a type of oil called sebum, a substance that serves as your hair's natural moisturizer and protection against dryness.

But while sebum is crucial for scalp and hair health, too much of a good thing can be problematic, especially when the goal is not to look like a greasy mess. And that’s why we shampoo. When we wash our hair, the soap or surfactants in the shampoo bond to the oils and dirt, helping to dissolve and rinse them away.

But if you don’t wet your hair at all, dirt and oils accumulate on the scalp's surface. This occurs at different rates for different people, as some of us have naturally oilier scalps than others. Some people's hair might start feeling oily within 24 hours of washing, while others can go a whole week before noticing the tell-tale sheen of oil buildup. There may also be factors like genetics, lifestyle, and even the climate we live in that could cause our hair to become greasy more quickly or more slowly. 

Additionally, your hair type plays a significant role in how fast this oil shows up. Fine or straight hair gets greasy more quickly because sebum travels down the hair shaft more easily. In contrast, textured or curly hair may take longer to appear greasy because the oil needs more time to work its way down the curls.

Our hair-washing habits also play a significant role in how greasy our hair gets. When we don’t wash our hair frequently, the oils and even product residue can build up over time and make our hair feel greasier than it actually is.

But what if we notice that our hair starts to get less greasy the longer we go between washes? Is this a sign that our hair is being, quite literally, conditioned enough and doesn't need to work extra hard to produce protective sebum?

What Does Oil Production Depend On?

As we mentioned, oil production can be influenced by various factors: genetics, which means inheriting sebaceous glands that are naturally more active; hormonal changes, such as those during certain menstrual cycle phases; diet, particularly sugary foods that elevate the hormones that stimulate sebaceous glands; and stress, which can prompt nervous system responses that adjust oil production to psychological and physiological changes.

However, another major habit that is our own doing and can significantly influence how oily our hair gets is frequent washing. As the surfactants in shampoo dissolve the oily substance that protects our skin and hair from the external world, our strands are left stripped and vulnerable. By becoming dry and brittle, the skin sends a message to the brain via the nervous system that it needs protection and nourishment, so the sebaceous glands start working overtime to oblige and provide. This results in hair that gets greasy quickly and needs washing even more frequently, leading to a never-ending cycle of locks that are seemingly impossible to keep clean.

So, Can You Actually Train Your Hair To Go Longer Between Washes?

So if frequent washing can trigger the sebaceous glands to produce more oil, it's only logical to think that the less you wash your hair, the less oily it will become, right?

Unfortunately, that's not how things work in our bodies. While frequent washing can lead to the need for more washing, the opposite is not true, and washing your hair less frequently doesn't necessarily mean it will become less greasy and remain clean for longer. This is because our sebaceous glands don't stop producing oil. So, not washing your hair frequently doesn't mean you are going to reach a point where your hair is so nourished that it doesn't need any more oil to keep it soft and protected.

Additionally, by not washing our hair so frequently, we have likely reduced the excess use of certain products, particularly stuff that can make the hair appear greasy, like conditioners that weigh it down and make it look shiny. This could give the illusion that our hair is less greasy when it's actually just being washed and styled less. Oil production is still happening as usual.

Brushing our hair frequently also evenly distributes the oil along the hair shaft, making our hair appear less greasy on the scalp and more moisturized on the ends. This can make it look like the longer we leave our hair between washes, the less greasy it gets, but in reality, we’re just moving away the oil from the scalp, not reducing its volume.

Finally, several coincidental factors, such as humidity, sweating, or even visiting different locations, may alter how greasy our hair looks. If, let's say, your hair lasts longer between washes in winter, this may be due to the fact that many of us sweat less during the cold season, and the air is also dryer, reducing the humidity that can make our hair look greasier. Or, if you notice your hair getting greasier faster after spending some time in a large city, this may be because pollutants in the air, like particles found in exhaust fumes, can stick to the oils on our scalp, adding an extra layer of grease and temporarily changing the texture of our hair.

Ultimately, the production of oil is a natural process that cannot be stopped or slowed down by simply changing our washing routines. This is why there's no scientific evidence that you can actually "train" your hair to become less greasy in the way many of us hope is possible, but you’re also not crazy if you feel like your hair is less oily when you don't wash it as frequently.

The Risks of Not Washing Your Hair for Too Long

While stretching out washes can be beneficial for oil control and overall scalp and hair health, there are some risks to letting it go for too long. Apart from looking greasy, oil and dirt buildup on the scalp can lead to clogged hair follicles, potentially resulting in hair loss, as the new hair will struggle to grow through the buildup.

Additionally, inflammatory skin conditions such as seborrheic dermatitis, a common cause of dandruff, redness, peeling, and flaking, is another common occurrence in those who go without washing their hair for long periods. This is because the yeast that naturally lives on our scalp feeds off the oils in our hair, causing it to overgrow and inflame the skin.

Moreover, excessive oil and dirt accumulation can also attract bacteria that thrive in warm, moist environments, increasing the risk of infections like folliculitis or acne on the scalp, which can become severe and lead to years of treatment, as well as discomfort and hair loss.

So, while washing your hair less frequently can be beneficial, finding the right balance and not going too long without a good cleanse can help you avoid potential risks to declining scalp and hair health.

How To Prolong the Time Between Washes

Now, while frequently washing your hair is necessary for overall hair health, we can all admit that we can't be asked to do it every day, especially if we have long or thick hair that takes forever to dry and style. The good news is you can actually prolong the time between washes without sacrificing your hair health (or social life) in the process.

Here are some simple tips and tricks:

• Shorten Your Hair: This can make styling quicker and easier.

• Get Regular Trims: Keeping your hair trimmed will reduce the surface area where grease can build up.

• Adjust Your Hair Length to Your Lifestyle: If you're working out a lot or live in a humid area, consider a style that works better with frequent washing.

• Use Powder: Baby powder can absorb excess oil and help you push your next wash day a little further without causing too much buildup.

• Use a Gentle Shampoo: Surfactant-free shampoos may not give you a squeaky clean feel, but will keep buildup at bay and maintain scalp and hair health.

• Apply Mists and Water-Based Serums: Lightweight, water-based serums can give your hair that freshly washed shine without weighing it down the way oils do.

• Try the Micellar Water Hack: Micellar water is not just for makeup removal – it can be sprayed on your scalp to gently cleanse and refresh, giving the appearance of freshly washed hair.

While "training" your hair to get less oily may not be a practice that makes much sense scientifically, there are certainly ways to go longer between washes without sacrificing hair health or appearance. Finding the perfect balance between your hair type, needs, and washing habits can certainly help you achieve healthy, beautiful hair that looks clean and voluminous, even on days when you'd rather sleep in for an extra hour than squeeze in a wash.