How Does Shampoo Work?

How Does Shampoo Work Featured Photo

I take hair care very seriously. I ensure to thoroughly read about and research hair care products I’m planning on trying. I don’t want anything which I know nothing about touching my hair – I’m just not risking it.

Hair care is a very personal journey to me. It’s more than just shampoo and conditioner for me. I’ve spent a lot of my time researching and reading multiple resources to understand how my own hair works.

Sometimes it’s important to learn how certain products work to get a deeper understanding of how they can benefit you most effectively.

A shampoo is a staple in anyone’s hair care routine. If you’re curious how shampoos work, I’ve got you covered!

How Does Shampoo Work?

(Almost) Everyone uses hair shampoo. It’s a pretty straightforward personal care product. Wet your hair, pour some amount on, slather it on your hair, rinse it out, and you’re good to go.

But if you’re wondering how exactly shampoo works, we’re here to break it down for you.

The skin produces sebum. This also means your scalp produces this greasy substance, much like in other areas of your skin i.e. your face.

Sebum is not at all a bad thing like how it seems. It actually protects the hair and hair follicles. Sebum protects the hair from drying out as your day goes by. As it coats your hair, it gives it a healthy and beautiful-looking shine.

Though essentially a hair protectant, sebum also attracts dirt and dust from your environment. This dirt and dust sticks to your hair. And the longer you go without washing your hair, you end up with dirty, dull, and sticky hair.

This is where shampoos come to the rescue.

Why not wash with just water?

Now you might be wondering, “can’t I wash my hair with only water and no shampoo?”

That sebum on your hair your scalp naturally produces is, well, oil. And we all know it from basic science that water and oil do not mix. Sebum is naturally hydrophobic and doesn’t mix with and instead repels water. So no matter how much water you use, you won’t be able to wash off this sebum and the dirt sticking to it.

Shampoos are formulated with detergent. Don’t worry though because these detergents aren’t exactly the same type found in other harsher cleaning agents. These are specially-formulated for use on the hair.

The detergent agent in shampoos acts as a surfactant. This lowers the surface tension between water and oil. This then enables water to wash away the oily molecules by separating them.

A surfactant has two distinct parts: a hydrophilic group, which attracts water, and a hydrophobic group, which hates water. The hydrophobic group can also be referred to as lipophilic, which means oil-loving.

The hydrophilic group attracts and binds to water and repels oil; while the lipophilic group attracts and collects oil and repels water. (See where we’re going with this?)

This is how the surfactant reduces surface tension on your hair shaft. In this way, the shampoo is able to remove the oil and dirt from your hair strands.

This science behind it allows shampoo to carry the sebum and dirt along with it as you rinse it off.

Why not wash oily hair with soap?

Both soap and shampoo are technically cleaning agents. However, their chemical makeup means it’s not advisable to use soap on your hair.

Hair has a natural pH level of about 4-5, making it acidic. Soaps, on the other hand, have a normal pH level of about 9-10. While it’s effective for cleaning and removing dirt from skin, for hair, not so much.

Using regular soap on your hair can lead to dry, brittle, and damaged hair.

Typical Shampoo Ingredients

Detergents and surfactants aren’t the only shampoo ingredients. We will be diving deep below on more typical shampoo ingredients below:

Conditioning agents

Shampoo works by dissolving and washing away the protective layer of sebum and natural oils on your hair shaft. Shampoos work to replace this protective layer by incorporating conditioning agents in their formulas.

These conditioning agents come in the form of silicones and fatty alcohols. Silicones help detangle hair strands and smooth down the hair cuticle, leaving hair soft. Fatty alcohol keeps static under control and helps tame fly-away and frizzy hair. These conditioning agents can also help add shine to your hair shaft.


On top of cleaning hair, many shampoos are also formulated with various protectants to protect the hair. Many of these protecting agents protect the hair against heat damage, UV rays, and even chemicals from other styling products.

Functional ingredients

Shampoos need to be thick so they don’t just run through your fingers when you pour an amount for application. They also need anti-microbial properties and preservatives to extend their shelf life. These are what’s known as functional ingredients.

Cosmetic ingredients

Cosmetic ingredients don’t affect a shampoo’s cleaning properties. These include fragrance, color, and pearlised agents (this gives shampoos that shimmer) that improve the overall experience of washing with shampoos.

Types of Shampoo

When you’re shopping for a new shampoo, it’s important to note that there are different types of shampoo you can choose from:

  • Everyday shampoo
  • Clarifying shampoo
  • Volumizing shampoo
  • Moisturizing shampoo
  • Strengthening shampoo
  • Dry shampoo
  • Color-safe shampoo
  • Anti-dandruff shampoo
  • Organic shampoo
  • Curly hair-friendly shampoo
  • Shampoo bar
  • Shampoo for acne

These are just of the more common shampoo types. And with many industry innovations, there are more types you can find on the market.

What affects the type of shampoo to use?

Your hair type largely affects the type of shampoo you use.

If you have oily hair, avoid hydrating, smoothing, and moisturizing shampoos. Clarifying shampoos are great but don’t let yourself overuse it, otherwise, you end up with dryness.

Dry hair would benefit from moisturizing, hydrating, and smoothing shampoos. If you deal with itchiness and flaking, tea tree oil and menthol shampoos usually help.

Those with thick hair would have different shampoo needs than those with finer or even thinning  hair. The same goes for those with straight hair vs. those with curly, wavy, or coily hair.

If you’re more prone to sensitivities, natural shampoos without chemicals and preservatives are the way to go. Some shampoos are formulated for special use on colored hair. Also, pregnancy can cause aversions to certain smells or sensitivities that you didn’t experience pre-pregnancy. See the the top picks for shampoo for pregnancy.

Hormones can also affect your hair in different ways, which is why shampoo for menopausal hair is formulated especially for women with these concerns.

Remember, choose a shampoo with your hair type in mind. Not all shampoos work the same for all hair types. If you have hair extensions, you might want to check out these shampoos and conditioners for extensions.

Shampoo and Water Type

How hard or soft is your water at home? The type of shampoo you use might not pair well with your water type if your shampoo isn’t washing out or isn’t cleaning well.

Those with well water often have hard water issues, but when a softener system is overcompensating, well water can become too soft too. It’s a delicate balance. Learn more about the best shampoo and conditioner for hard water, plus some important considerations to make when choosing a product.

Do You Need Hair Shampoo That Lathers?

If you don’t already know, lather in shampoos actually aren’t necessary. They don’t have any effects on a shampoo’s cleaning or conditioning functions. Lathering shampoos were created simply because consumers enjoy the experience of bubbles.

The bubbles and lathering of cleaning products like shampoo and soap lead to a squeaky clean feeling, which isn’t always a good thing. This is why many cleaning products, including shampoos, have some form of conditioning agents.


Shampoos are an essential personal care and hygiene product. Everyone uses or has used one but do we know exactly how shampoos work?

The skin, including the scalp, produces a greasy substance called sebum. Though it sounds like a bad thing, it’s not. Sebum works to protect your hair and hair follicles. It helps prevent your hair from drying, and instead leaves you with a beautiful, healthy-looking shine.

Though essentially a protectant, sebum attracts dirt and dust. This leads to hair that looks and feels oily, dull, and sticky.

Like most cleaning products, shampoos have specially-formulated detergents that act as a surfactant. This lowers the surface tension between water and oil. As a result, shampoos are able to collect this oily sebum substance so it washes away with water once you rinse shampoo out.

Sebum is an oily substance and we all know by now that oil and water don’t mix. This is why you can’t use just water to wash your hair. Water cannot get rid of this oil and all the dirt along with it.

And that has been our guide on how shampoos work!