Reader question:

Cindy, I’ve stumbled upon a half-used bottle of my once-favorite lavender-scented shampoo in the back of my bathroom cabinet—it’s been hiding there for a good while. Does shampoo have an expiration date, and how can I spot if it’s not okay to use anymore? Thanks.

Elyse Haugen
Bloomington, Minnesota

Hy Elyse, let’s get straight to the point:

“Yes, all brands and types of shampoos do expire. Once the shampoo is expired, it’s expired. There’s nothing you can do to save it,” says Janet Biggers, a hairdresser and owner of Hair by Janet Biggers

“Shampoo is a water-based product that can be a breeding ground for bacteria and harmful microorganisms to grow. In an open bottle this process can happen quicker,” Biggers adds.

Stick around to learn more about your shampoo’s lifespan and what to do with expired shampoo.

In this article, you’ll learn:

• What is shampoo’s shelf life
• Types of shampoo and their shelf life
• Side effects of using expired shampoo
• Effectiveness of expired shampoo over time
• Is it safe to use expired shampoo
• How long can shampoo last before it goes bad
• Importance of shampoo ingredients
• How can you tell if shampoo has gone bad
• How to properly store shampoo
• FDA shampoo products regulations
• What affects shampoo’s shelf life
• How to read shampoo expiration dates
• Shampoo shelf life of popular brands
• What experts say about shampoo shelf life
• What to do with bad shampoo
• Frequently asked questions about expired shampoo

What is a Shampoo’s Shelf Life?

A shampoo’s shelf life determines how long it lasts before it’s rendered unusable. Several shampoo manufacturers boast different high-performing ingredients. But overall, their shelf life is often similar.

Shampoo Shelf Life If Unopened

If the shampoo bottle you found is unopened, then its shelf life can range between 2 to 4 years.

Now, you also have to consider the environment you found it in. Was the bottle exposed to the sun, heat, or lots of humidity? If so, then chances are it’ll go bad faster.

Shampoo Shelf Life If Opened

You may have used one shampoo, but suddenly found a better option and neglected the old one.

Then, you eventually decide to use the old opened one. Maybe you’re all out of shampoo that day. Whatever the scenario, you’re wondering whether it’s safe.

Well, an opened bottle of shampoo can last for around 6 months to a couple of years.

Other Types of Shampoo and Their Shelf Life

So, we’ve covered normal human shampoo, but what about other kinds?

Dry Shampoo

Dry shampoos are a perfect fix when you’re late to work but don’t want to go with your hair smelling bad or looking greasy.

Just know if your bottle of dry shampoo has been around for 3+ years, your hair may end up smelling and looking worse. Once these products expire, the ingredients become less effective. And when they’ve been expired for a long time, using them will have the opposite effect of what you expect.

Baby Shampoo

Baby shampoo isn’t necessarily restricted to baby use. Its gentle effect is sometimes beneficial for adult hair as well.

Plus, if you have little ones around, it’s easier to share one big bottle of baby shampoo than buy separate products.

That being said, you may have left that bottle in a drawer somewhere and forgotten about it.

Then you uncover it from the depth of your bathroom cabinet during spring cleaning. Of course you want to make use of it! Well, most common brands of baby shampoos have a 3-year shelf life.

Dog Shampoo

I don’t know about you, but I tend to lose my fur baby’s shampoo a lot. I sometimes think she hides it somewhere because of how much she dreads bath time.

If you do end up finding that long-lost bottle, make sure its shelf life hasn’t exceeded 12 to 18 months if opened. Meanwhile, if it’s unopened, it can last a long 3 years.

Organic Shampoo

Organic shampoos may often include natural ingredients such as oils and aloe vera. This, in turn, often lessens their lifespan compared to your average shampoo.

Sealed, unused organic shampoos can last 1 to 2 years. But if the bottle is opened, then the product will last anywhere between 6 to 18 months.

What Are the Side Effects of Using Expired Shampoo?

You’re better off not using shampoo in the first place over reaching for a bottle past its expiration date. The side effects aren’t pretty.

Expired shampoo can end up making your hair look dirtier and duller than before. Plus, your scalp may become hot or irritated from the expired chemicals in the shampoo. Consequently, you’ll be itching and experiencing bouts of discomfort.

Aside from the scalp, your eyes aren’t safe from expired shampoo either. They can get teary from the irritation and itchiness. In more extreme cases, your shampoo could host a colony of bacteria. This could result in a nasty scalp or eye infection.

And the worst-case scenario?  A bacterial scalp infection may result in patches of lost hair, plus wounded areas on your scalp.

With all this in mind, a quick trip to a convenience store for a new bottle is well worth delaying your shower.

How Effective is Expired Shampoo Over Time?

The properties of expired shampoo are less effective than a newly bought bottle. Expired products undego a chemical change, which inhibits the efficacy of the ingredients.

Overall, an old shampoo product will not be as potent or functional when trying to clean your hair. The same can be said for your conditioner. Expired shampoo and conditioner are likely to cause more harm than good over time.

Is It Safe to Use Expired Shampoo?

Now, you may opt to ignore the expiration date and use your expired shampoo anyway. But what’s the point of using shampoo when it’s not effective at its main purpose?

Think of it this way. Would you take expired meds, knowing they’re useless and you’re just ingesting empty pills? Probably not.

The main difference here is that you’re not only taking empty pills. On top of that, you’re risking scalp infections and bacterial growth among other side effects.

How Long Can Shampoo Last Before It Goes Bad?

You may have decided to make a bulk purchase of shampoos. In this case, you’ll want to make sure that you purchase just enough to last you no more than 2 to 4 years.

Let’s assume that you shampoo your hair every other day. A regular 8.4 oz bottle of shampoo can then last you for around a couple of months.

This means you’ll use 7 bottles per year. With that logic, even if you bulk buy around 10 bottles, it should be fine as long as you don’t open the bottles that aren’t in use.

The Importance of Shampoo Ingredients

A shampoo bottle’s expiration date is largely related to its ingredients. One of the most crucial ingredients in keeping your bottle shelf-stable is preservatives. These ingredients prevent any bacterial growth and contamination from happening to your shampoo.

Some commonly used preservatives include sodium benzoate, sorbic acid, and benzyl alcohol. As time goes by, the ingredients degrade in potency, which is when the expiration clock runs out.

Shampoos are also made of other critical ingredients such as sodium lauryl sulfate and citric acid.

The prior’s function is to clean your hair from dirt and oil by creating a lathering effect. Meanwhile, citric acid helps lower the pH level of the shampoo to keep your hair’s pH levels stable.

Like preservatives, both ingredients break down over time and lose their functionality. Shampoos also contain thickeners, opacifiers, and other additives. All of these expire too.

How Can You Tell if Shampoo Has Gone Bad?

As a good rule of thumb, if the shampoo has gone clumpy and smelly, ditch it. You can tell a shampoo has gone bad from its curdled texture.

Plus, if the color looks different from when you first bought it, then chances are the bacteria got to it. Additionally, if you open the bottle and are hit with a pungent smell, you’ll want to toss it.

Now, if you go so far as to pour it over your hand to use it, you may also notice that it doesn’t lather well. If one or all these criteria are met, it’s time to let that old bottle go.

How to Properly Store Shampoo

Improper storage can erase some months of your shampoo’s shelf life. To properly store your shampoo bottle, you can keep it on a mounted shelf in your shower area. Make sure they’re closed so water doesn’t get inside.

Generally, if the bottle’s not in use, then you should store it in a cool, dark place like your cabinet.

FDA Shampoo Products Regulations

US law doesn’t require cosmetic products such as shampoos to carry an expiration date.

The Food and Drug Administration (FDA) does regulate shampoo products, but doesn’t necessarily approve them.

The FDA requires shampoos to be labeled appropriately with the conditions of use. The organization can respond against companies that don’t provide labels.

What Affects Shampoo’s Shelf Life?

The factors that affect a shampoo’s shelf life are whether the bottle is opened or not. If the latter is true, then the product’s shelf life is longer.

Plus, proper storage also plays a part. Shampoo kept in a cool, dark place will last longer than a bottle directly exposed to sunlight or high heat.

Aside from that, the ingredients are also worth considering. Does the shampoo contain fewer preservatives and more naturally derived ingredients? If so, it’ll have a shorter shelf life and be more sensitive to the environment.

How to Read Shampoo Expiration Dates

Every shampoo bottle needs a printed expiration date on its label. Otherwise, it isn’t FDA-compliant. Usually, the expiration information is found at the back of the bottle, near the bottom area.

PAO Number

Expiration information is found in the form of a period-after-opening (PAO) number.

Janet told me, “Check the back of your shampoo bottle, there’s a symbol that looks like a jar, inside that jar symbol is a number and a letter “M”. That is called a “period after opening” (PAO) symbol, it is commonly located near the bottom of the packaging label. Once the product is open you have a shelf life of that many months.”

Manufacture Batch Code

The manufacture batch code helps companies trace the shampoo’s batch number. The batch code will then show the production date of each batch of shampoos. The code is usually found stamped or printed on the product, sometimes on the bottom of the bottle.

Shampoo Shelf Life of Popular Brands

With most popular shampoo brands, the expiration date for unopened bottles falls between 2 to 4 years. This is true of all the brands listed below. Meanwhile, opened bottles have a shelf life between 6 to 12 months.

To check the production date and how old the shampoo bottle is, I suggest going to this batch expiration date checker and choosing the brand of shampoo you have. Next, enter the batch code of your product. It’ll give you the shampoo’s production date and age.

• Pantene
• Tresemme
• Dove
• Head & Shoulders
• John Frieda
• Paul Mitchell
• Clairol Herbal Essences
• Garnier
• Aussie
• Aveda
• Suave
• Johnson’s Baby Shampoo
• Matrix
• Redken
• Vo5

What the Experts Say About Shampoo Shelf Life

According to Vince Spinnato, a cosmetic chemist, “Most shampoos will last for 18 months after being opened and will be marked with a PAO (period after opening) on the label.”

Another cosmetic chemist named David Petrillo has a lot to say about using expired shampoos. He explains that:

“Many things… can happen when a product expires. Many times the chemical components can separate, giving the product a clumpy, unnatural appearance. It can potentially be harmful as the ingredients [have separated. They] were not meant to be applied in this manner.”

“Even though the shampoo does not stay on the hair as long, the ingredients still penetrate the outer layers of skin on the scalp. This could hurt the follicles and irritate the skin, which may lead to an increase in hair loss.”

What to Do with Bad Shampoo?

If the shampoo has gone bad and become clumpy and smelly, then the ideal thing to do is throw it away. You can repurpose the bottle for other products.

You might be tempted to use the expired shampoo in some way, and I get it. I hate wasting anything. I repurpose whenever possible. But because the ingredients are expired, they can’t do their job anymore. Even if you try to use the shampoo for laundry or cleaning, you won’t get good results.

FAQ

Can you use expired shampoo?

No, because using expired shampoo isn’t beneficial for your hair. The old product may produce unwanted side effects such as dull hair and an itchy scalp.

Can expired shampoo cause hair loss?

Yes, expired shampoo may cause patchy hair loss. The root cause of the hair loss could be a bacterial or fungal infection from the expired product.

How do I know if my shampoo expired?

You can tell a shampoo has expired from its PAO number. Physical changes like bad odor, clumpy feel, and discoloration are also telltale signs of expiration.

How long after the expiration date can you use shampoo?

The maximum number of years you can keep the shampoo bottle is 4 years. After that, its effectiveness will wear off.

What can you do with old shampoo?

You can use old shampoo as a cleaning detergent for your toilet or makeup brushes. But you can’t do this with expired shampoo, so make sure it doesn’t have any funky smell, curdled feel, or odd color.

What happens if you use expired shampoo?

The side effects of using expired shampoo include an itchy and irritated scalp. Your hair won’t get clean, and may take on a dull, greasy appearance. Plus, you may also get a bacterial or fungal infection which could result in patchy hair loss.