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How Long Does Shampoo Last?

July 18, 2023 3 min read

How Long Does Shampoo Last?

You might be surprised to learn that shampoo has a shelf life. It can expire, and when it does, it’ll range from useless to harmful to your hair. The age of the shampoo can also impact everything from texture to fragrance, changing the way that the shampoo looks, feels and smells when you go to lather it.

To get the most out of your bottle, you’ll want to pay attention to its label. You can even look for certain forms and ingredients of shampoo that last longer than others. From vegan hair oil to plastic-free dry shampoo, you can assemble a collection of hair care products that will last.

How Long Shampoo Lasts

The first thing to know about shampoo is that opening the bottle starts the clock. Unopened, it’s good for three years or so; opened, the countdown can range anywhere from six to 24 months.

How do you know the longevity of your specific shampoo brand? Look for its PAO number. PAO stands for period after opening, and it’s a little symbol that some manufacturers put on their bottles. It will say either 6M, 12M, 18M, or 24M. The M stands for month, so a bottle with 6M on it will be good for six months after opening.

Natural products tend to last longer than synthetic ones. This rule of thumb applies to everything from organic shampoo to all-natural deodorant, which is one of the reasons why we make our products the way that we do.

How To Know When Your Shampoo Has Expired

Generally speaking, you won’t need any detective work to know when a bottle of shampoo has expired. You’ll see the red flags:

  • Odd smells
  • Clumps and lumps
  • Color changes
  • Not lathering anymore
  • Mold and fungi 

Benefits of Shampoo Bars and When To Switch Types

Some people can’t get through an entire bottle of shampoo before it goes bad. They might use a rotation of shampoos, for example, or they might have something like a curly girl routine that doesn’t require much shampoo at all.

In these cases, we recommend alternatives like our shampoo bars. They’re made with natural ingredients, and they come in a wide variety of scents. You can also extend their longevity by keeping them in a wooden or silicone soap dish in your tub.

Find the Perfect Shampoo and Conditioner Set

holding up shampoo and conditioner bar

The Risks of Using Old Shampoo

Some shampoos are made with artificial chemicals. These can include perfumes, preservatives, color dyes and more.

Over time, these chemicals start to change their composition. Their exact changes will depend on what they are, what they’ve been mixed with, and how much time has passed. They could break down and lose their potency, for example, or they could start attracting bacteria and growing mold.

In most cases, using expired shampoo is more of an inconvenience than a health hazard. It just won’t work like it used to, so you might not get a good lather or a long-lasting scent. Another danger of old shampoo is that it won’t be as effective at cleansing, so you could still have build-ups of the product in your hair even after a shower.

When To Replace Your Shampoo

Obviously, you’ll want to throw out your shampoo when it starts exhibiting visible signs of decay. But what about shampoo that looks and smells normal? Can you still use it even if it’s old?

If you’re still within the number on the PAO label, you should be safe. If that number has come and gone, it’s not worth the risk.

Note: Some products don’t have a PAO number. PAO numbers can also be disregarded in certain situations. With our hair and body oils, for example, we use low-waste packaging in the form of refillable bottles, so there’s no expiration date for how long you can continue using them.

Shop Our Vegan Hair and Body Oil

pouring hair body oil

Keeping Your Shampoo Safe and Fresh

Freshness is one of the qualities that determines a good shampoo. Make sure to keep an eye on its expiration date, and consider investing in our jars, bars and bottles of hair and beauty products made with all-natural compounds. They’ll last longer, and they’ll be better for your hair, too!