Is it bad to use expired shampoo?

Table of Contents

Quick answer

Using expired shampoo is generally not dangerous, but it may be less effective at cleansing hair and more likely to cause dryness or irritation. The best practice is to discard shampoo after its expiration date. However, if unexpired shampoo is unavailable, expired shampoo can be used in most cases without major issues. Pay attention to any changes in smell, texture, or performance and discontinue use if significant degradation occurs. Storing shampoo properly and checking expiration dates can help avoid problems with expired products.

Does shampoo expire?

Yes, shampoo does expire. The expiration date indicates when the manufacturer believes the product will reach the end of its shelf life under proper storage conditions.

Shampoo expires for a few reasons:

The preservatives that prevent bacterial growth lose effectiveness over time.
The chemicals that create the cleaning and foaming action can degrade.
The fragrance oils can oxidize and smell rancid.

Separation or thickening of ingredients may occur.

Once opened, shampoo has an even shorter shelf life – around 18 months. Exposure to air, heat, and light causes the product to deteriorate faster.

What happens when you use expired shampoo?

Using expired shampoo is not inherently dangerous, but it may lead to the following issues:

Reduced effectiveness – expired surfactants may not cleanse hair and scalp as well
Dull, flatter hair – conditioned oils degrade over time
Brittle, dry hair – nourishing ingredients like proteins break down

Buildup on hair – separation of ingredients can leave residue
Irritation – degradation creates compounds that sting eyes or irritate skin
Unpleasant odor – fragrance chemicals oxidize and smell rancid

Separation – formula breaks down and doesn’t lather well

The preservatives in shampoo prevent microbial growth during use, so health risks from bacteria, viruses, or fungi are low. But degraded formulas may not clean thoroughly and can damage hair over time.

How long past expiration is shampoo still safe to use?

Shampoo can often be safely used for several months past its expiration date, if it has been properly stored unopened. However, it’s ideal to use unexpired products whenever possible.

Here are some general guidelines for how long expired shampoo may still be usable:

Unopened shampoo – up to 1 year past expiration
Opened shampoo – up to 6 months past expiration

Discolored or separated shampoo – up to 3 months past expiration
Smells rancid – discard immediately

Pay attention to any changes in performance, texture, separation, or smell. If you notice signs of degradation, it’s best to replace the shampoo even if the expiration date hasn’t passed.

Proper storage extends the shelf life. Keep shampoo in a cool, dry place and avoid extremes of heat and humidity. Refrigeration can prolong freshness of opened bottles.

Does expired shampoo damage your hair?

Expired shampoo is unlikely to severely damage or break hair with one-time use. However, ongoing use of stale shampoo that is past its prime may gradually degrade hair health.

Some ways expired shampoo can negatively impact hair:

Inadequate cleaning allows residue buildup that weighs hair down
Loss of moisturizing oils makes hair dry, brittle, and prone to breakage
Lack of nourishing proteins leads to weaker, more porous hair over time

Harsher cleansing strips natural oils and upset scalp balance
Separated formulas coat hair unevenly and unevenly

Mild effects like dull, limp, tangled, or frizzy hair are more common. But prolonged use can make hair prone to damage like split ends and breakage.

Those with chemically treated or colored hair may notice fading and brassiness as protective oils and pigments degrade.

If hair shows severe changes after switching to expired shampoo, return to a fresh product. See a dermatologist if unexplained hair damage occurs.

Do you need to wash your hair again after using expired shampoo?

It’s not strictly necessary to wash hair again after using expired shampoo. But if the shampoo didn’t lather well or hair feels dirty, grimy, or stripped after drying, a second wash can remove any residue.

Follow up with a deep conditioner to replenish moisture and smooth the cuticle after using stale shampoo.

Look for these signs that a second wash is recommended:

Limp, dull, tangled, or straw-like texture

Residual buildup at the roots and scalp
Hair feels grimy or sticky after drying
Flakes, itchiness, or irritation of the scalp

Lack of typical squeaky clean feel after shampooing

Washing with a fresh, clarifying shampoo can remove any product buildup. Then condition as usual to restore moisture.

How to prolong the life of shampoo

To get the longest use out of your shampoo and avoid premature expiration:

Purchase shampoo with an expiration date as far out as possible.
Check expiration dates and use oldest products first.
Store shampoo in a cool, dark place like a bathroom cabinet.

Keep the cap tightly sealed when not in use.
Don’t transfer shampoo into decorative bottles which may not seal well.
Limit exposure to humidity, heat, and direct sunlight.

Don’t keep shampoo in the shower where it may get wet.
Clean hair and hands before using to avoid contamination.
Use clean utensils if decanting shampoo into smaller bottles.

Discard if you notice a rancid smell, discoloration, separation, or layer of surface scum.

With proper care, unopened shampoo lasts over 3 years, and opened bottles stay usable for about 18 months. Avoid buying more than you can use before it expires.

Signs your shampoo has expired

Watch for these common signs that your shampoo has expired and should be replaced:

Change in consistency – becomes thicker, thinner, or prone to separating
Color change – darkening, lightening, or layer of scum on surface
Weakened fragrance – fresh notes disappear leaving flat or chemical smell

Formula separation – ingredients settle into layers rather than blending
Poor lathering – scant suds even with vigorous washing
Stinging eyes – irritant compounds form as ingredients degrade

Scalp irritation – redness, itching, or sensation of burning
Flaking or residue – left behind after washing
Degraded bottle – corroded cap, leaks, or softening plastic

A sudden worsening in texture, scent, or performance indicates the shampoo has hit the end of its usable life. Expired products with these issues should be replaced.

Does shampoo expire if never opened?

Even if the bottle is never opened, shampoo will eventually expire. However, unopened shampoo lasts significantly longer – up to 3 years past the expiration date on the label.

The sealed bottle protects the shampoo from:

Exposure to oxygen and air causing ingredients to oxidize
Contamination from hands, hair, and water during use
Loss of fragrance molecules through evaporation

Interactions between ingredients destabilizing the formula
Microbes which can grow once air enters the bottle

So while unopened shampoo isn’t immune to expiration, it stays fresher longer than opened products. Store it properly in a cool, dark place and avoid unnecessary heat exposure.

Use by the labeled expiration date for maximum freshness and performance. But in most cases, unexpired shampoo may be safely used over a year past its expiration date if the bottle remains factory sealed.

How to tell if shampoo is expired?

Here are tips for identifying expired shampoo by sight, smell, and feel:

Check the expiration date – This date gives a general guide for when to discard.

Observe the color – Unexpired shampoo should be uniform in color. Darkening, lightening, or layers signal degradation.

Examine the bottle – Leaks, corroded cap, separation, and mushy bottle point to expiration.

Watch for clumping – Thickening, clumping, settlement, and failure to blend when shaken means components have broken down.

Take a whiff – Fresh shampoo smells vibrant. Rancid, sour, or chemical odors indicate spoilage.

Feel the texture – Expired shampoo may feel slimy, grainy, watery, or syrupy compared to a creamy unexpired product.

Do a patch test – Apply a dime size amount to inner arm. Irritation or lack of lather hints expiration.

When unsure, go by changes in look, scent, feel, and performance rather than relying solely on the expiration date.

Can you use shampoo after it separates?

Shampoo may still be used after some separation occurs, but it signals degradation has begun. Separation happens when ingredients of different densities settle into distinct layers rather than staying emulsified.

Oily components like silicones and waxes rise to the top.

Heavier moisturizers and oils sink to the bottom.
Lighter foaming agents and water remain suspended in the middle.

Mild separation doesn’t automatically spoil the shampoo. But it indicates chemical breakdown is underway.

Before use, shake vigorously to reincorporate the layers. Watch for poor lathering, scalp irritation, lack of cleansing, and buildup that shows further separation.

If issues emerge, discard the shampoo. But with relatively fresh separation and vigorous mixing, it may still perform adequately though past its prime.

Separation accompanied by rancid smell, texture changes, or bottle corrosion signals the shampoo is unsafe and should get tossed.

What ingredients cause shampoo to expire faster?

Some types of ingredients degrade faster and hasten shampoo expiration. These include:

Preservatives – Parabens, formaldehyde donors, phenoxyethanol. As they break down, bacterial growth accelerates spoilage.

Natural oils – Plant oils and butters turn rancid through oxidation. Avocado, coconut, and olive oils have shorter shelf lives.

Proteins – Keratin and collagen proteins denature and lose repairing abilities over time.

Emulsifiers – Polysorbates and PEGs help blend ingredients. Their breakdown causes separation.

Surfactants – Sodium lauryl sulfate, betaines. Deterioration reduces foaming and cleaning action.

Dyes and pigments – Added colorants fade or shift hues as they degrade.

Fragrances – Essential oils and synthetic perfumes evaporate and oxidize with age.

Shampoos with sizeable amounts of delicate natural oils, proteins, and fragrances may expire faster than synthetic surfactant-based types.

Do you need to shake expired shampoo before use?

Aggressively shaking or mixing expired shampoo before use can temporarily revive some products to improve performance.

Shaking achieves:

Re-blends separated ingredients that have settled into layers.

Distributes components like oils and silicones evenly so they spread over hair better.
Incorporates air to fluff up the formula and boost lathering.
Breaks up thickened texture to restore fluidity.

However, shaking doesn’t reverse chemical breakdown of aging ingredients. The shampoo will continue degrading with time.

Plus vigorous agitation can cause more separation after use.

Shake curdled, separated, or thickened shampoo as a temporary fix. But frequent mixing shouldn’t be relied on with regularly expired products. The need for constant shaking means it’s time to replace the shampoo.

Does refrigerating your shampoo make it last longer?

Yes, refrigerating opened shampoo can effectively prolong its shelf life, freshness, and performance. Cooler fridge temperatures slow chemical reactions that cause ingredients to degrade.

Studies show refrigeration extends the usability of shampoo and conditioner by over 10 months compared to storing at room temperature.

Some benefits of refrigerated storage include:

Slows oxidation and rancidity of oils and fragrances
Minimizes evaporation and loss of aromas
Reduces microbial growth by limiting spoilage

Stops separation by keeping ingredients blended
Maintains viscosity so formula doesn’t thin or thicken
Prevents discoloration caused by heat and light

For best results:

Transfer opened shampoo to fridge within a week after first use.
Store in a closed bottle to limit air exposure.

Use clean utensils to avoid contamination.
Keep the temperature under 40°F for optimal stability.

Refrigeration works best for natural shampoos with plant oils, butters, proteins, and juices. It extends shelf life of any shampoo, but very synthetic types see less benefit.

Does microwaving expired shampoo help?

No, do not microwave expired shampoo. Microwaving will not make it safe or usable. Heating will further degrade the formula, creating potential scalp irritation or hair damage.

Problems with microwaving old shampoo:

Ingredients deteriorate faster rather than improving.

Rancid oils and waxes melt, contaminating the shampoo.
Proteins and beneficial components are destroyed.
Water content evaporates, altering the formula.

Harsh chemicals may leech from plastic bottles into the shampoo.
Separated layers don’t fully re-emulsify.
Bacteria and mold can survive microwaving.

Additionally, the shampoo may overheat and boil over or even catch fire. Chemical reactions with separated or volatile ingredients make results unpredictable.

Rather than microwaving, use heat to melt down leftover shampoo to add to DIY hair products if desired. But don’t apply heated expired shampoo directly onto hair or scalp.

Conclusion

While using expired shampoo comes with some risk of reduced performance or irritation, it does not pose serious health hazards in most instances if the bottle was properly stored. Hair may feel drier, become stripped of oils, or look limp and dull with an older shampoo. But extreme damage is unlikely from occasional use.

Check bottles for signs of separation, discoloration, and smell before using old shampoo. Stop use if irritation occurs. Proper storage helps prolong shampoo life, as does buying smaller bottles you can use up quickly. Refrigeration of opened bottles also slows deterioration.

Ultimately, replacing shampoo once it expires is ideal for hair health and hygiene. But keeping an eye on product condition can help determine if an expired shampoo is still safe in a pinch when fresh products are unavailable. With vigilant inspection and care, most shampoos last months past their expiration date while retaining effectiveness.