6 Little-Known Facts & Popular Myths About Shampoo

Shampoo is one of the most popular beauty products in the world. But how much do you really know about this it? Here are six little-known facts about shampoo, as well as five myths that people often believe to be true.

Fact: It can expire

Even if you don’t open it, shampoo has a shelf life. If you ever asked yourself can shampoo expire, the answer is yes. To be safe, shampoo’s effectiveness expires depending on the brand, and some can last for years if you don’t open it. Although it is great for hair, these ingredients can cause skin irritations, allergic reactions, and rashes if used often or incorrectly! 

If your shampoo does expire, don’t panic. You can significantly extend the shampoo’s shelf life by using shampoo bars or diluting it with water. This is why it’s actually smarter to buy it in smaller bottles.

This shampoo is mostly made of natural ingredients, so you can keep it for up to two years before tossing it. But if your shampoo isn’t natural or organic, then technically speaking, the rule of thumb is: toss after 18 months. 

Fact: Shampoo cleans your hair and scalp

You’ve read it right, shampoo can clean your hair and scalp. It’s not just shampoo that can clean your hair, it is also soap as long as the shampoo has a pH level between four and six which means it is neither too acidic nor too alkaline. This shampoo helps to reduce oil buildup on the scalp by dissolving sebum (natural oils produced by our glands).

Sodium lauryl sulfate or sodium Laureth sulfate are two popular ingredients in shampoo that cause lathering and bubbling up action when you use them together with water. These chemicals provide nice smelling foam but they’re said to be harmful because of their possible links to cancer and organ toxicity. For those who want an alternative for these chemical-based shampoos, try using baby shampoo instead which is more gentle on your hair and scalp.

Fact: Shampoo doesn’t remove all the dirt from your hair

Contrary to popular belief, shampoo doesn’t remove all the dirt from your hair. Shampoo cleans by trapping dirt in water and then rinsing it away with water, taking some dirt along with it. This is why professional shampooers often rinse several times to make sure they’ve removed as much of the oil build-up as possible since shampoo can only do so much on its own.

When you think about shampoo ingredients like sodium lauryl sulfate or ammonium Laureth sulfate, an amphoteric surfactant specifically designed for cleaning purposes should be what comes to mind first because these are two chemicals that clean very well. It’s due to their detergency properties which mean they’re able to bind everything including grease, cosmetics, and other grime together allowing them to be removed by shampooing.

Myth: You only need to use the shampoo once a week

A popular myth is that shampoo should only be used once a week to prevent the shampoo from drying out your hair. In reality, shampooing every day will not harm your scalp or strip essential oils from the rest of your body. 

The shampoo contains surfactants that can remove dirt and oil from our skin, but they do so by binding to oil molecules and water. These shampoo molecules are then rinsed away, along with the oil they bind to.

Myth: It’s not important to clean the bottles you store your shampoo in

Shampoo bottles should be kept clean because shampoo can become contaminated with bacteria. This is especially true if it was stored on its side or you applied your shampoo using dirty hands.

If the shampoo has been contaminated by bacteria, it can cause dandruff and make hair look duller than usual and these are two things to avoid! So keep those bottles clean for more beautiful (and healthier) shampoo.

Myth: You can’t wash your hair with soap or body wash because it will dry out 

Soap and body wash cannot be used as shampoo for a couple of reasons. 

  • First, shampoo is designed to cleanse the scalp and hair of dirt and oil, soaps are not formulated with this in mind. 
  • Second, the shampoo contains ingredients that keep it from drying out your hair like soap does (hello sodium Laureth sulfate). 
  • Lastly, shampoos contain additives that are specially designed to cleanse hair.

Now that you’ve read a breakdown of some interesting facts and myths about shampoo, we encourage you to do your research when buying the right type of brand and product for your needs.