All beauty products expire. This is a hard reality for people who have a tendency to save products for later or put off using them because they are expensive or discontinued. But alas, beauty products have a shelf-life, and your shampoo and conditioner are not immune. Two cosmetic chemists share how to know if your shampoo is expired, whether or not it's safe to use expired shampoo, and how to make your bottle last longer.
- Vince Spinnato, cosmetic chemist and founder of TurnKey Beauty Inc.
- David Petrillo, cosmetic beauty chemist based in Reno, Nevada
How to Tell If Shampoo Is Expired
Shampoos typically contain water, surfactants (like sodium lauryl sulfate), conditioning agents, and usually preservatives. Some common synthetic preservatives include parabens, formaldehyde-releasers, fragrances, and thickeners (natural shampoos tend to be free of these additives). Shampoos may also include essential oils and vitamins like vitamin E. Regardless of the exact ingredients, here's how to pinpoint whether the shampoo has gone bad.
Look for an Expiration Date
Unopened shampoo should last about two to three years. However, once opened, that timeframe depends on the "period after opening" date.
"Most shampoos will last for 18 months after being opened and will be marked with a PAO (period after opening) on the label," says cosmetic chemist Vince Spinnato. "If the bottle has never been opened, it will expire three years from the date of purchase." Even the best shampoos will degrade in quality over time.
Some products will have a PAO number (period after opening) listed on the back, labeled as 12M, 18M, or 24M, where M stands for months. This refers to shelf-life after opening. "If it's a true GMP-compliant [good manufacturing practices] facility making the product, this is something they test to ensure its efficacy after a certain period of time through an accelerated shelf-life testing process," says cosmetic chemist David Petrillo. "If it does not have a PAO, contact the company and see if you can reference a batch number to the product."
Once the expiration date (or PAO date) is known, write it somewhere prominent on the product bottle so you remember when to use it by.
Examine the Contents of the Bottle
Most of us probably don't remember when we opened our shampoo. To tell if yours has expired, look for some visual clues. "The color, texture, and smell of a shampoo will change to the point that it doesn't look or smell right," says Spinnato.
"There are many things that can happen when a product expires," says Petrillo. "Many times the chemical components can separate, giving the product a clumpy, unnatural appearance."
As a rule of thumb, assume your shampoo is too old if it has an odd odor, looks clumpy, has changed color, or doesn't seem to be lathering as it once did. This might be difficult to notice if your shampoo is in an opaque bottle and you cannot see the separation.
Why You Shouldn't Use Expired Shampoo
If you're tempted to use expired shampoo anyway, it will likely be a waste of your time. Expired shampoo isn't effective, which can result in your hair looking dull and dirty. In addition, because the preservatives have probably lost their potency, the product is no longer stable.
The shampoo's chemical change can cause itching or irritation to your scalp. After that, mold and bacteria begin to grow, potentially triggering bacterial breakouts or fungal diseases on the scalp.
"[Using expired shampoo] can potentially be harmful as the ingredients were not meant to be applied in this manner or to penetrate the skin separated," says Petrillo. "Even though the shampoo does not stay on the hair as long, the ingredients still penetrate the outer layers of skin on the scalp.
The bottom line: If you've been experiencing issues like dandruff, itchy scalp, overly greasy hair, or hair loss, consider your shampoo's age before taking any extreme measures. Is it past its expiration date? If so, just throw it out.
If you have used expired shampoo, there are a few things to look out for before you seek professional advice. If your scalp has become itchy, irritated, or inflamed and doesn't get better in a few weeks with home care, you should make an appointment with your dermatologist. Additionally, if your hair texture and type have drastically changed, it might be beneficial to visit your dermatologist or haircare professional so they can check for and treat any underlying issues.
How to Make Shampoo Last Longer
While the expiration date and the effectiveness of the ingredients is key in determining whether to keep or toss shampoo and conditioners, how the products are stored and cared for can also contribute to an early demise from the shower. Here are some tips to keep in mind:
- Close the bottle cap or lid tightly after each use to minimize exposure to water and humidity.
- Keep products away from sunlight, which can degrade active ingredients and cause them to spoil faster.
- Store unopened shampoo in a cool, dark place since heat and light can break down the shampoo formula, reducing its effectiveness.
Frequently Asked Questions
Does conditioner expire faster than shampoo?
Conditioner and shampoo both have the same shelf life (two to three years for an unopened bottle and up to 18 months for an opened bottle). The type of conditioner (deep, leave-in, moisturizing) does not affect the shelf life either. Since both hair products utilize similar chemicals, preservatives, and ingredients, one doesn't necessarily expire faster than the other.
Does natural shampoo expire faster than other shampoos?
Natural shampoos tend to expire faster than conventional shampoos because specialty products (prescription, organic, sulfate-free) contain fewer synthetic preservatives. (The lack of synthetic preservatives might cause a shorter shelf-life.) Ingredients like essential oils, plant extracts, and natural preservatives are also more prone to breaking down more quickly.
Can expired hair products cause hair loss?
There is no scientific proof that using expired shampoo and conditioner directly causes hair loss. However, expired hair products can change the composition of your hair texture and scalp microbiome, which can then lead to thinning hair and hair loss. If you are concerned about hair thinning or hair loss, see a dermatologist or trichologist to address your concerns.
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