5 Simple Ways to Tell If Your Shampoo Has Gone Bad
Question from a reader:
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
Hi Elyse, here’s the main idea:
“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 contains water, which makes it easy for bacteria and germs to grow. Biggers says that if the bottle is open, this can happen even faster.”
Keep reading to find out how long your shampoo lasts and what you should do if it’s expired.
In this article, you’ll learn:
What is a Shampoo’s Shelf Life?
The shelf life of a shampoo tells you how long it stays good to use. Many shampoo brands use special ingredients to improve their products. Still, most shampoos have about the same shelf life.
Shampoo Shelf Life If Unopened
If the shampoo bottle is still sealed, it usually lasts between 2 and 4 years.
You should also think about where you found the bottle. Was it left in the sun, near heat, or in a very humid place? If yes, it will likely spoil more quickly.
Shampoo Shelf Life If Opened
You might have tried one shampoo, but then discovered a better choice and stopped using the first one.
So, you end up using the old, already opened bottle. Maybe you ran out of shampoo that day. No matter the reason, you start to wonder if it’s still safe to use.
Once opened, a bottle of shampoo usually stays good for about 6 months up to 2 years.
Other Types of Shampoo and Their Shelf Life
We already talked about regular human shampoo. But what about different types?
Dry Shampoo
Dry shampoos are great when you’re running late for work and want fresh, clean-looking hair without any bad smell or oily look.
If your dry shampoo is over three years old, it might make your hair look and smell bad. After the product expires, its ingredients stop working well. Using very old dry shampoo can actually harm your hair instead of helping it.
Baby Shampoo
Baby shampoo is not just for babies. Its mild formula can also be good for adult hair.
Also, if you have young kids, using one large bottle of baby shampoo is simpler than purchasing different products for each child.
However, you might have put that bottle in a drawer and then forgot it was there.
You find it hidden deep in your bathroom cabinet while doing spring cleaning. Naturally, you want to use it! Most popular baby shampoo brands stay good for about three years.
Dog Shampoo
I don’t know about you, but I often misplace my pet’s shampoo. Sometimes, I wonder if she hides it on purpose because she really doesn’t like taking baths.
If you find that old bottle, check how long it has been open. If opened, it stays good for about 12 to 18 months. If it is still sealed, it can last up to 3 years.
Organic Shampoo
Organic shampoos usually have natural ingredients like oils and aloe vera. Because of this, they often do not last as long as regular shampoos.
Unopened organic shampoos usually stay good for 1 to 2 years. Once you open the bottle, it will last about 6 to 18 months.
What Are the Side Effects of Using Expired Shampoo?
It’s safer to skip shampoo altogether than to use one that has expired. Using old shampoo can cause unpleasant side effects.
Using expired shampoo can make your hair look even dirtier and less shiny. The old chemicals might also cause your scalp to feel hot or irritated. This can lead to itching and discomfort.
Expired shampoo can also harm your eyes, not just your scalp. It may cause irritation, making your eyes watery and itchy. In severe cases, old shampoo might contain bacteria. This can lead to serious infections on your scalp or in your eyes.
In the worst case, a bacterial infection on your scalp can cause hair loss in certain spots and create sores on your scalp.
Considering all this, it’s better to wait and buy a new bottle at a nearby convenience store before taking your shower.
How Effective is Expired Shampoo Over Time?
Expired shampoo does not work as well as a new bottle. Over time, the product changes chemically. This change reduces the efficacy of the ingredients.
In general, old shampoo does not clean your hair as well as a fresh one. The same goes for conditioner. Using expired shampoo or conditioner can do more harm than good as time passes.
Is It Safe to Use Expired Shampoo?
You might decide to use your expired shampoo anyway. But if it no longer works well, why bother using it at all?
Imagine this. Would you use expired medicine, knowing it won’t work and you’re just swallowing useless pills? Most likely, no.
The key difference is that you’re not just taking empty pills. You also risk scalp infections, bacteria growth, and other side effects.
How Long Can Shampoo Last Before It Goes Bad?
If you plan to buy shampoos in bulk, make sure you get only enough to use within 2 to 4 years.
If you wash your hair every other day, a standard 8.4 oz bottle of shampoo should last about two months.
This means you will use about 7 bottles each year. So, if you buy around 10 bottles in bulk, it should be okay. Just make sure not to open the extra bottles until you need them.
The Importance of Shampoo Ingredients
The expiration date of a shampoo mostly depends on what is inside it. Preservatives are very important because they stop bacteria from growing and keep your shampoo safe to use for a longer time.
Popular preservatives are sodium benzoate, sorbic acid, and benzyl alcohol. Over time, these ingredients lose their strength. When this happens, the product reaches its expiration date.
Shampoos also contain important ingredients like sodium lauryl sulfate and citric acid.
The first ingredient helps wash away dirt and oil by making the shampoo foam up. Citric acid lowers the shampoo’s pH, which helps keep your hair’s pH balanced.
Just like preservatives, these ingredients degrade over time and stop working well. Shampoos also have thickeners, opacifiers, and other additives. These also expire eventually.
How Can You Tell if Shampoo Has Gone Bad?
A good rule is to throw away shampoo if it smells bad or looks lumpy. A curdled texture means the shampoo has expired.
If the color has changed since you bought it, bacteria may have started to grow. Also, if you open the bottle and notice a strong, bad smell, it’s best to throw it away.
If you pour some onto your hand and see it doesn’t create much lather, that’s another sign. When you notice this or any of the other signs, it’s best to throw out the old bottle.
How to Properly Store Shampoo
Storing your shampoo the wrong way can shorten its shelf life by several months. To keep it safe, place the bottle on a shower shelf. Always close the cap tightly to stop water from getting in.
When you are not using the bottle, keep it in a cool, dark spot such as your cabinet.
FDA Shampoo Products Regulations
In the US, there is no legal requirement for shampoos or other cosmetic products to have an expiration date on the label.
The Food and Drug Administration (FDA) oversees shampoo products, but it does not officially approve them.
The FDA requires shampoos to have clear labels that explain how to use them. The agency can take action against companies that do not include proper labels.
What Affects Shampoo’s Shelf Life?
How long a shampoo lasts depends on whether the bottle has been opened. If it is still sealed, the shampoo will stay good for a longer time.
Also, how you store shampoo matters. Keeping it in a cool, dark spot helps it stay good longer than leaving it in sunlight or hot areas.
Also, look at the ingredients. Does the shampoo have fewer preservatives and more natural ingredients? If yes, it won’t last as long and may react more to changes in the environment.
How to Read Shampoo Expiration Dates
All shampoo bottles must have an expiration date printed on the label to meet FDA rules. You can usually find this date on the back of the bottle, close to the bottom.
PAO Number
You can find expiration information by looking for the period-after-opening (PAO) number.
Janet explained, “Look at the back of your shampoo bottle. You will see a small jar symbol with a number and the letter ‘M’ inside. This is called the ‘period after opening’ (PAO) symbol. It is usually found near the bottom of the label. After you open the product, it will stay good for that many months.”
Manufacture Batch Code
The batch code lets companies track the specific batch of shampoo. It reveals when that batch was made. You can usually find this code stamped or printed on the bottle, often on the bottom.
Shampoo Shelf Life of Popular Brands
Most popular shampoo brands have an unopened shelf life of 2 to 4 years. Once opened, you should use the shampoo within 6 to 12 months.
To find out when your shampoo was made and how old it is, visit this batch expiration date checker. Select your shampoo brand, then type in the batch code from your bottle. The tool will show you the production date and how long ago it was made.
What the Experts Say About Shampoo Shelf Life
Cosmetic chemist Vince Spinnato says that most shampoos stay good for about 18 months after you open them. You can find this information on the label, marked as PAO (period after opening).
Cosmetic chemist David Petrillo shares important insights about using shampoo past its expiration date. He says:
“When a product expires, many things can happen. Often, the chemicals separate, making the product look lumpy or strange. This can be unsafe because the ingredients were not meant to be used like this.”
“Although shampoo is rinsed off quickly, its ingredients can still soak into the scalp’s outer skin. This might damage hair follicles and irritate the skin, which could cause more hair to fall out.”
What to Do with Bad Shampoo?
If your shampoo is lumpy and smells bad, it’s best to throw it out. You can reuse the bottle for something else.
I understand not wanting to waste things, so you might think about using expired shampoo for something else. But once the ingredients expire, they stop working well. Even if you try it for cleaning or laundry, it won’t work effectively.
FAQ
Can you use expired shampoo?
No, using expired shampoo is not good for your hair. It can cause problems like making your hair look dull or giving you an itchy scalp.
Can expired shampoo cause hair loss?
Yes, using expired shampoo can lead to uneven hair loss. This hair loss might happen because the old shampoo contains bacteria or fungus that cause infections.
How do I know if my shampoo expired?
You can check if a shampoo is expired by looking at its PAO number. Signs like a strange smell, thick or lumpy texture, or a change in color also show it has gone bad.
How long after the expiration date can you use shampoo?
You can keep the shampoo bottle for up to 4 years. After that, it will not work as well.
What can you do with old shampoo?
Old shampoo works well as a cleaner for toilets or makeup brushes. But do not use it if it is expired. Check that it does not smell strange, look lumpy, or have a weird color before using.
What happens if you use expired shampoo?
Using expired shampoo can cause your scalp to feel itchy and irritated. Your hair might stay dirty and look dull or greasy. Also, old shampoo can lead to bacterial or fungal infections, which may cause patches of hair to fall out.