Skip to content

Does Shampoo Expire? How to Tell If It’s Gone Bad

BY Felicia Ler

Spring-cleaning your restroom has been on your to-do list since, like, forever. After taking stock of your shower caddy and bathroom cabinets, you realize you still have some bottles of old shampoo or leftover shampoo bars. But you can’t make out each shampoo’s expiration date.

But the question is: does shampoo expire? If so, how can you tell if you should give your old shampoo a shot or buy a new bottle? Read on to find out the answers. 

Does Shampoo Expire?

First up, does shampoo expire? The answer is a resounding yes. But you should also know that the exact use-by date of a shampoo depends on the manufacturer.

That’s because the Food and Drug Administration (FDA) doesn’t regulate the cosmetic shelf life for beauty products like shampoos. In fact, the FDA has stated that “There are no U.S. laws or regulations that require cosmetics to have specific shelf lives or have expiration dates on their labels.” As such, it boils down to the brand to ensure product safety, which, at Function of Beauty, is something we take very seriously.

Personal care products like shampoos generally come with an expiry date and/or a “period after opening” suggestion. The latter refers to the optimal shelf life of shampoos. The FDA explains that this is “the length of time you can expect a product to look and act as expected and to stay safe for use.”

Does shampoo expire: different expiry dates

You can check for either piece of information on your shampoo’s packaging, so you know how long it should reside in your shower stall. In the case of the “period after opening” (PAO) symbol, simply look for a tiny container logo with a number. It’s commonly spotted at the bottom of the packaging label in a range of:

  • 6M: Your shampoo is good for six months after opening
  • 12M: Your shampoo is good for 12 months after opening
  • 18M: Your shampoo is good for 18 months after opening
  • 24M: Your shampoo is good for 24 months after opening

If you still aren’t sure how long your shampoo can last after you twist the cap off, try emailing or calling the brand’s customer service department to check with them directly.

How Long Can Shampoo Last Before It Goes Bad?

Shampoo does expire, but you’re probably curious about how long your shampoo can last before you bid it adieu.

As a rule of thumb, an unopened bottle of shampoo can probably last for 2-4 years if properly stored. Meanwhile, an opened bottle of shampoo may go bad anywhere between six months to two years. Of course, this would also depend on the type of shampoo formula specifically, the nature of the preservatives used.

If you’re wondering why preservatives are used in hair care, it’s because many shampoos are water-based, making them the perfect breeding ground for harmful microorganisms. That’s why shampoo products usually contain either natural, naturally derived, or synthetic preservatives to safeguard against such bacterial contamination.

However, natural shampoos may have a shorter shelf life than synthetic versions. As a 2018 study puts it, natural preservatives are less potent than man-made ones in certain kinds of product formulations.

You may have also correctly predicted that opened bottles of shampoo usually turn bad faster than unopened ones. With every use, there’s a higher chance of bacteria entering the bottle and mixing with the product inside. Even if you carefully store your unopened shampoo, it will eventually expire because preservatives gradually wear off with time, making the product unusable.

You can expect a use-by range of a few months to a few years, depending on the ingredient list and the state of your shampoo product.

How To Tell if Your Shampoo Has Expired

You now know the answer to the question, “Does shampoo expire?” The next step is to understand the warning signs of a shampoo gone bad.

For opened and unopened shampoos, it’s always recommended to check the expiration date first. If that’s not printed on the bottle, look for the PAO logo to help you decide if your shampoo is here to stay or go.

If neither of these is available, or you simply can’t remember when you first bought and/or opened the shampoo, there are a few ways to tell if your shampoo has expired:

  • Do a visual inspection: Uncap the shampoo bottle and take a look at the liquid inside. If it’s gone bad, usually the oil-based ingredients (say, butter and essential oils) will separate at the top. Also, the shampoo may look discolored or even lumpy due to chemical changes like oxidation.
  • Let your nose guide you: Take a cautious whiff. Does the fragrance seem milder than it used to? Or perhaps your nostrils are assaulted by a strong rancid smell? Whichever the case, your shampoo has likely expired.
  • Wash your hair with it: If there’s no clear evidence that the shampoo has gone off — and you’re willing to chance it — use it. If you notice the shampoo’s cleansing abilities are somewhat lackluster (say, there’s significantly less lather), it’s a clear sign that it’s lost its efficacy and should be thrown away.

As you can see, “does shampoo expire” isn’t the only thing you need to know. Equally important are the detective skills that can help you determine if the product is past its prime.

Can You Use Expired Shampoo?

As with all expired products, it’s generally a good rule not to use expired shampoo for health and safety reasons.

Typical shampoo ingredients — including additives, preservatives, and sulfates — break down over time. Using an expired shampoo on your scalp may then lead to inadequate cleansing that could leave your hair dry, dull, and lifeless-looking.

On top of that, the ingredient degradation sets off a mini-explosion of chemical changes inside the shampoo bottle. Although such chemical activity isn’t visible to the naked eye, it may trigger a slew of dermatological problems, such as scalp itching or irritation. Not worth the risk!

How to Properly Store Shampoo

To ensure your shampoo isn’t on its last breath before its use-by date, give it a proper home. Keep the shampoo out of direct sunlight and other heat sources. It’s also good practice to store unopened haircare products in a cool, dark place.

After every use, make sure the lid is completely closed, or the bottle is stored in a way that external elements, like shower water, can’t get inside easily. At Function of Beauty, every shipment of your custom-made hair care comes with optional pumps for fuss-free storage.

Take Care of Your Shampoo So It Can Take Care of You

Does shampoo expire? You bet! Look out for the expiration date and/or recommended “period after opening” date. Keep in mind that the exact best-before date is dependent on the product itself.

To recap, unopened shampoos usually take longer to expire than opened ones. You will also have to factor in the product’s ingredient list. Those with a higher concentration of natural (or naturally derived) substances and fewer synthetic preservatives will likely have a shorter shelf life.

Case in point: Function of Beauty’s custom haircare range uses a mix of synthetic and naturally derived ingredients that are clean and backed by science. That’s why our best-before date is typically 12 months, depending on the specific formulation you choose.

To easily track your shampoo supply, subscribe and become part of the Function of Beauty fam for an auto-refill every three months, on top of our exclusive price discount. You can delay, pause, or cancel your subscription in your account settings at any time.

So, what are you waiting for? Take our hair quiz today!