Long has there been debate over the perfect hair washing schedule. We are often told that less is more and washing too frequently can be detrimental to our hair and scalp. As a hairdresser myself, I have been preaching to my clients that two to three times a week is the optimum shampoo schedule. I have told my clients that their natural oils are good for them and that washing your hair too frequently can cause our bodies to produce more oil. Upon reflection I have  realised I have no clue how factual this recommendation is, I was merely relaying to others what I had been taught myself. The idea that I could be spreading misinformation forced me to undertake actual research uncover the truth regarding shampoo practices. What new found knowledge I would gain along the way would allow me to make informed recommendations to my clients. Here I am post research and I can say I am pleased and surprised with the amount I feel I have learned. As for what is often dismissed as a mundane daily task, there is a lot to consider when we are shampooing our hair. There are many factors to consider; age and hair type, individual medical conditions all play a large role in ones shampoo habits. However consideration must be given to the very biology of our scalps and the purposes for its functions. Before we can delve into this swirling information vortex, there are a few key principles we must first understand.

If we are going to understand how often we should be shampooing our hair, we need to understand what we are actually washing away. Commonly referred to as oil or grease, Sebum is an oil produced my the sebaceous glands in our skin. When sebum is mixed with sweat it becomes acid mantle. This is a thin acid film that covers our entire body and protects us from harmful bacteria and virus’. Sebum alone also plays a similar role in our hair. Our hair is a porous material and sebum acts as a protective coating which keeps the each hair strand moisturised and the cuticle layer closed. When the cuticle layer is closed our hair is unable to absorb potentially harmful substances like pollution, smoke and more. Sebum plays a defensive role in the health of our hair and scalp. 

I know this is where you are going to stop me and say “Adam are you suggesting I go through life with oily hair because it’s good for me?”Never fear, I would never force that way of life upon you. My point is simply, a little sebum is vital to the health of our hair and scalp. The problem is that our sebaceous glands don’t just produce some oil and then stop. They continue to produce sebum every day and in some cases they can produce a lot.

Why so Greasy?

If you feel like you are constantly battling excessively oil hair every day, it is likely you are dealing with over productive sebaceous glands. This is very common and can be caused by a number of contributing factors. Excessively oily hair can be due to Seborrhea; a common skin condition. Seborrhea isn’t necessarily linked to underlying health issues. It is often due to hormonal activity, which is why it is most common in individuals in their Teens, Twenty’s and Thirty’s. Seborrhea isn’t a danger to your health however if you are concerned, it can be very helpful speaking to you GP.  Another medical condition of note is Seborrheic dermatitis, also known as cradle cap which is relatively common. The exact cause isn’t known however it is thought to be linked to too much sebum being present in the sebaceous glands and on the scalp. Symptoms include oil and flaking on the scalp, which can be prone to irritation.

The appearance of overly greasy hair can also be caused by a number of environmental factors. A study* conducted in 2015 found people living in highly polluted enviroments such as cities were more prone to having scalp issues such as irritation, dandruff and excessive oil. Diet can also be a cause, an article** published in 2016 linked dairy and high-glycemic diets to the amount of sebum produced by the skin. There are many reasons one can be dealing with over productive sebaceous glands and we are very familiar with its age-old remedy, Shampoo. How many of us are actually aware of the process taking place when we shampoo the oil from our scalps?

How Does Shampoo Work?

The majority of us have had a relationship with Shampoo our entire lives. It’s a staple in our routine which, I’m certain, most of us take for granted. How often do we consider shampoo and its role it plays in our lives? Shampoo contains ingredients known as surfactants. The average household knows surfactants as soaps. Surfactants contain compounds known as sulphates that along with removing dirt and impurities from our hair and scalp, allow the oil to be bonded to water. This enables the shampoo to escort the oil off our hair and scalp, and then down the bathroom drain. Doesn’t sound overly sinister, does it? So why the big debate? Surely washing our hair everyday can’t be that harmful. In all honesty this question is a can of worms and once opened the arguments endlessly multiply. I am going to do my best to sift out the crud and leave you with the essential pearls of wisdom.

So Whats the Problem?

We established that a little bit of sebum is actually good for the hair. Oil when present keeps the hair and scalp moisturised and the cuticle layer closed. This gives way to our first objection to frequent shampooing; it deprives you of your natural oils. Washing your hair daily doesn’t allow sebum to spread far enough to do its job. This will lead to dehydration of the hair and scalp. When hair is dehydrated the its cuticle layer is open. An open cuticle isn’t able to keep moisture in and harmful environmental forces out. Hair colour is at risk of fading as our hair unable to shield itself from UV rays and free radicals from the sun. Hair damage and breakage is on the table as the hairs first line of defence, sebum, is being constantly washed away. A dehydrated scalp will eventually become irritated, this problem is intensified when the individual is already prone to dryness, or deals with dandruff or eczema. There are other contributing factors can escalate the issue, such as age. Our prime oil producing days tend to fall in our teens, twenties and thirties. This is due to puberty and hormones. The fact is the older we get, the dryer we become. Most individuals in their forty’s and over simply don’t need to be washing their hair as frequently as they were decades prior because their bodies aren’t producing the same quantities of oil.

Another individual factor to consider is hair texture. Straight, fine hair allows sebum to spread more easily down the hair shaft and tends to appears oilier sooner. Thick, wavy and curly hair tend to be dryer in nature because the sebum has a much harder time spreading around. When curlier hair types dry out it results in an ill-defined curl and frizz. Without the presence of sebum our hair and scalps are deprived of their first line of defence and in danger dehydration. Excessive shampooing deprives our hair and scalps of the moisture our bodies have provided for it. When the our hair dries out its health suffers, colour will fade and curls will turn to frizz. 

If still you are not convinced, I would ask you to consider your microbiome. “MY WHAT?” You say! Yes, your microbiome. I have mentioned our skins acid mantle, which is a combination of sebum and sweat that acts as a protective barrier against bacteria and viruses. Our microbiome serves as similar purpose. Our skin is covered in thousands of species of good bacteria. With the acid mantle, our microbiome works to maintain our skins pH, which creates an inhospitable environment for harmful bacteria. Our microbiome deprives foreign microbes of nutrients and produces molecules that deter harmful bacteria from taking up residence on our skin. Frequent shampooing constantly strips back our scalps removing dirt and harmful bacteria but it also washes away our microbiome and leaves our bodies unprotected. An individuals skin can try and compensate for this lack of protection send the sebaceous glands into working overtime producing sebum to rebuild that protective layer. And thus perpetuates the cycle of washing.

Solving the Problem.

We have arrived at endless cycle of excessive sebum production and frequent shampooing. Often individuals are aware of the impact their shampoo habits have on their hair and scalp, however it is the daunting task of confronting the cycle that is keeps them trapped inside it. The thought of having to live with oily hair as you gradually lessen your weekly shampoos  is a horrifying notion. To help you combat the problem, I have curated a modest list of helpful suggestions that might allow you to break from the chains of you shampoo routine and dance in the light of life lived where humans and sebum exist harmoniously. 

Google trends graph depicting interest in the no-poo movement from 2004 -2021

I find in instances such as these, its best to start with the extremes. Some individuals decide to go cold turkey and ditch shampoo completely, or “no-poo” as the movement is often referred to as. The term no-poo reached its peak in countries like Canada and Switzerland in February 2004 and then again in April 2006. Medically a lot of people do not need shampoo, rinsing with water alone can be enough to remove dirt and dandruff. No-poo individuals rely on mostly water, sometimes employing solutions like vinegars and other natural acids such as citrus to remove pollution, pollen and sweat from the hair. This will do the job, however my main objection to this school of thought is you are denying your hair of the moisturising benefits of a traditional shampoo or conditioner.

Image Featuring: Kevin.Murphy Fresh.Hair & KMS HairPlay Makeover Spray

Dry Shampoo I would argue to be a wonderful band-aid solution. Despite what the name suggests, dry shampoo doesn’t actually cleanse your hair. Dry shampoos main function is depositing a fine layer of starch or similar on the hair. This starch absorbs excess oil, lessening its visibility but not removing it completely. Sebum and starch remain in the hair until the hair is next shampooed. I offer up Dry Shampoos as a fantastic band-aid solution as they lessen the visibility of sebum present in ones hair and therefore make it a little easier to get through the day unwashed. This allows the individual to break the daily shampoo habit and start washing every other day.

Image Featuring: Kevin.Murphy Re.Store & KMS MoistRepair Cleansing Conditioner

A similar approach would be to adopt a cleansing conditioner into your shampoo routine. Often referred to as “co-wash”, the cleansing conditioner would be considered the lesser of two evils. It has a smaller amount of surfactants and therefore results in a lighter cleanse. Not as effective as shampoo at removing dirt and oil, it still removes some while administering nourishment. This helps with making the hair feel a little fresher without stripping it back completely. Co-washes are great to use every other day when you are trying to shampoo less and break your routine.

The last method I am going to offer up and probably my personal favourite is to evaluate your shampoo and conditioner. Make sure you are using a product that delivers the right amount of cleanse that your hair needs and be sure that you conditioner isn’t too heavy for your hair type. If cleaned throughly your hair is likely to not feel that dirty tomorrow. Use a more clarifying wash when needed and make sure you shampoo at least twice. Conditioners that deliver a large hit of moisture can be too powerful on finer hair types and might cause them to feel oilier sooner. Speak to your stylist about your current product choices and discuss if there is a better fit for you. For those who are dealing with over productive sebaceous glands, my advice would be to look for sebum-regulating shampoo and conditioners. These are products that directly address your scalps oil production rate. De Lorenzo’s Control range utilises Australian Lemon Aspen in order to regulate sebum production. Similarly Davines Rebalancing Shampoo boasts a “normalising and rebalancing formula for problems of excess sebum production.” Sebum-regulating products give your scalp a little pep talk about working too hard and help the sebaceous gland to calm down.

What Are You Going to do About it?

We have uncovered the inner workings of the scalp and the shampooing process. We have explored the benefits and problems our habits create. On this journey of discover, one thing I couldn’t find was the magic number of how many times an individual should shampoo their hair each week. I can’t say I am surprised. There are definitely too many factors to take into consideration from person to person. Health conditions, hair type, age, location all play a role in the health and production of your scalp. It is undeniable that some sebum is vital to the health of your hair and scalp. Excessive washing can strip away sebum and your skins microbiome leaving your hair and scalp exposed and dehydrated. No one wants to appear oily but it is not without purpose. There are many products out there you can use to disguise or manage your sebum. Whatever you do, I hope you now find yourself more informed and able to navigate the convoluted waters of shampooing practices with a certainty.

References:

HealthLine Web Article: How often should I wash my hair? by Mandy Ferreira

Medical News Today Web Article: Should you wash your hair everyday? by Zawn Villines

BYRDIE Article: The Truth About Shampooing Every Day, According to a Trichologist by Allie Flinn

Medical News Today We Article: What causes greasy hair after washing it? by Beth Sissons