Can mouthwash expire?
By
Dr Shivam Jha
This blog post will answer the question, “Can mouthwash expire?” and cover topics like different types of mouthwash and their expiration dates, how safe it is to use an expired mouthwash and the different household uses of an expired mouthwash.
Can mouthwash expire?
Yes, Mouthwash can expire. Most of the mouthwash, if stored properly, lasts for almost two or three years from the date of manufacture.
However, the expiration dates may vary depending upon the type of mouthwash and the composition of the mouthwash.
All You Need To Know About Expiration Dates
Expiration-date rules for dental products like mouthwash are different from that of food items. The Food and Drug Administration (FDA) regulates the expiration dates on any drugs.
An expiration date on a mouthwash bottle, gives you an idea of how long the components in the bottle will stay stable and how long the mouthwash would work effectively.
Stability is defined as the capacity of a drug substance or a drug product to remain within specifications
established to ensure its identity, strength, quality, and purity throughout the retest period or expiration dating period, as appropriate
Not all mouthwashes have the same expiry date. Let us understand how the shelf-life of mouthwash varies and how long they exactly last.
Shelf-Life Of A Mouthwash
Mouthwashes are categorised as Cosmetic and Therapeutic type by the FDA and American Dental Association (ADA).
Depending upon the type, the expiration-dates of the mouthwash vary.
Cosmetic Mouthwash:
Cosmetic Mouthwash is only to mask the bad breath and does not correct the dental condition causing bad breath.
FDA does not regulate cosmetic mouthwashes. However, you must be watchful about the expiration dates of the cosmetic mouthwashes.
Ideally, it is seen that a cosmetic mouthwash lasts for a year or two from the date of manufacture.
Therapeutic Mouthwash:
Therapeutic mouthwashes as the name suggests have therapeutic action and control dental conditions like gingivitis, tooth decay and periodontal diseases. They also help remove halitosis.
Therapeutic Mouthwashes contain ADA listed active ingredients such as fluoride, peroxide, essential oils, cetylpyridinium chloride, and chlorhexidine, all regulated by the FDA.
Normally, a therapeutic mouthwash lasts for two or three years. After the expiration date, the active ingredients in the mouthwash lose its efficacy and become ineffective.
Shelf-Life Of Therapeutic Mouthwash Based On Its Main Ingredient
All mouthwashes are different. Some mouthwash have alcohol, preservatives or antimicrobials as their main ingredient while others do not.
The composition is different for different mouthwashes and this affects how long the mouthwash will last with its full efficacy.
ALCOHOL BASED MOUTHWASH
Ethanol is the main ingredient in most alcohol-based mouthwashes.
Ethanol kills germs and bacteria and helps to reduce plaque and gingivitis by dissolving and dispersing essential oils like thymol or menthol.
Ethanol also acts as a preservative and helps alcohol-based mouthwash to last effectively for at least three years from their date of manufacture.
Depending on how you have stored them, factors like light, temperature, air and interaction with other ingredients also affect the expiration or shelf-life of the alcohol-based mouthwash.
ANTIMICROBIALS CONTAINING MOUTHWASH
Mouthwashes may contain both antimicrobials and alcohol or only antimicrobials. Chlorhexidine, a main antimicrobial ingredient, helps reduce and prevent plaque and gingivitis apart from acting as an preservative.
With time, antimicrobial agents in the mouthwash dissolve, break down and lose their effectiveness due the high-water content in these mouthwashes.
Chlorhexidine, one of the main antimicrobial ingredients in the mouthwash, is known to become harmful after its expiration date and therefore needs to be discarded.
Chlorhexidine based mouthwash may last around four to five years from the date of manufacture. However, it is always recommended to fully read the instructions, label and expiration date on the mouthwash bottle.
PARABENS CONTAINING MOUTHWASH
Parabens are the most common type of preservative used in mouthwashes.
Parabens help to prevent infections and also to keep a mixture stable.
Mouthwash containing parabens may last for more than a year after its expiration date.
According to a research paper published in 2004, parabens can enter the body through skin and cause hormonal changes leading to cancer.
Therefore, it is advised to avoid mouthwashes containing parabens or consult your dentist before using such products.
NO PRESERVATIVES (NATURAL MOUTHWASH)
Natural Mouthwashes are gaining popularity due the rising concerns associated with chemicals and their harmful effects on the body.
Purely natural mouthwash does not contain any amount of preservatives and therefore has a shorter shelf-life.
In case, your natural mouthwash does not have an expiration date mentioned, watch for the changes in appearance including color, texture and smell changes.
How Safe Is It to Use An Expired Mouthwash?
It is actually not safe to use an expired mouthwash or any other dental products for that matter.
The active ingredients such as fluoride, chlorhexidine and essential oils present in therapeutic mouthwash break down with time and lose their effectiveness to prevent tooth decay, gingivitis, periodontal diseases and eliminate bad breath after expiry.
Mouthwash after expiration date may contain bacteria and rancid ingredients, making it unsafe for use.
According to the Food and Drug Administration (FDA), expired mouthwash can cause oral and systemic infections and may also lead to life threatening infections like pneumonia and bacteremia in some individuals.
How To Retain The Effectiveness Of The Mouthwash?
To retain your mouthwash’s effectiveness, store it in a cool, dry, and dark place.
Ensure your mouthwash is not exposed to light, heat, and oxygen, or mixed with other ingredients.
Doing so, will prevent the breakdown of the active ingredients present in the mouthwash and retain its effectiveness.
Ways To Dispose Or Reuse An Expired Mouthwash
Disposing An Expired MouthWash
To dispose of an expired mouthwash, simply pour it off in the sink and in order to dispose of the bottle, use a dustbin.
Reusing An Expired Mouthwash
An expired mouthwash, though less effective, can be reused for many purposes. However, using it for any skin care purpose is not advised.
Following are some of the ways to reuse your expired, less effective mouthwash:
As a mosquito repellant
Expired mouthwash can be reused as a DIY mosquito repellant and can be pretty effective in repelling the mosquitoes.
For Laundry
Use your expired mouthwash to clean and remove odors from smelly socks and gym clothes.
Gardening: To keep Bugs Away
Expired mouthwash is an effective way to keep bugs away from your garden.
Spray diluted 1 part of Listerine with 2 parts of water over plants to keep bugs away and help your plants grow.
To keep Flowers Fresh
Replace the water in the flower vase with a mixture containing 1 tablespoon of mouthwash with 4 pints of water.
The mixture helps kill the decomposition accelerating bacteria and make flowers last longer.
ToothBrush Disinfection
Toothbrushes harbour germs if not cleaned regularly.
Take a small cup of mouthwash and leave your toothbrush submerged in it for 10 minutes. Rinse it after 10 minutes and your toothbrush is clean and fresh.
Dental Products And Their Expiration Dates
Toothpaste
Most toothpastes have a 2-year expiry from their manufacture date. After the expiration date, toothpastes lose their fluoride strength and eventually its plaque-fighting capabilities.
Dental Floss
Dental floss does not have an expiration date. However, after 1-year, it may lose its flavor and fray. If it doesn’t, you can continue using it.
Toothbrush
The toothbrush, which is packed and still in its cover, will never expire.
However, once used, it must be replaced every 3-months as recommended by dentists.
It is best to replace your toothbrush when it becomes fray or after 3 months or after a prolonged illness.
‘Beyond Use Date’ for Mouthwash: What Is It?
Beyond Use Date (BUD) for mouthwash is different from Expiration Date and is determined by the prescribing pharmacy based on several factors like:
- Dosage
- Rate of decomposition of solution after preparation
- Storage conditions
After this date, you will need to discard any remaining mouthwash and get a refill.
Conclusion
This blog post addressed the question, “Can Mouthwash Expire?” We understood about the expiration dates of different types of mouthwash, risk factors associated with using an expired mouthwash, ways to reuse the expired mouthwash for household purposes and how “Beyond Use Date” is different from “Expiration Date”.
FREQUENTLY ASKED QUESTIONS (FAQs): Can Mouthwash Expire?
Does Expiry Date Of Mouthwash Depend On Its Type?
Yes, the expiry date of mouthwash depends on the type of active ingredients it contains.
Most mouthwashes contain alcohol, antimicrobials or preservatives as active ingredients.
Alcohol-based mouthwashes can remain effective for almost three years while Chlorhexidine containing mouthwash can last for five years if unopened.
Natural mouthwashes have the least shelf-life as they contain no preservatives.
Is it OK to use mouthwash after the expiration date?
Mouthwash after its expiration date will have no beneficial effects on your mouth as all its active components break down, losing all their antiplaque and anticarial potential.
Should I rinse my mouth with water after using mouthwash?
No, you should not rinse your mouth just after using mouthwash and wait for at least 30 minutes.
Rinsing with water soon after mouthwash, reduces the antibacterial effects and increases the demineralization of your tooth enamel.
Saliva needs at least 30 minutes to establish protection for teeth enamel.
Why do you have to wait 30 minutes after using mouthwash?
You must wait for at least 30 minutes after using mouthwash because saliva needs at least 30 minutes to establish protection for teeth enamel, letting the fluoride infuse completely.
Rinsing or eating or drinking before 30 minutes after mouthwash, washes off the fluoride and leaves the tooth enamel unprotected to dental caries.
Is it normal for mouthwash to burn?
Yes, it is normal for mouthwash to burn as you rinse your mouth with it.
Mouthwash contains ingredients like alcohol and menthol, which produces a burning sensation.
Can I use mouthwash as a disinfectant?
No, mouthwash cannot be used as a disinfectant as the alcohol concentration in mouthwash is very low to have a disinfectant effect.
The disinfectant at the drugstore contains 70-99% alcohol compared to mouthwashes that have concentrations of alcohol up to 25%, falling short of an antiseptic effect.
Alcohol in mouthwash is used as a carrier agent for ingredients like menthol as well as a preservative, not to kill bacteria.
Which mouthwash kills the most bacteria?
Mouthwash containing Xylitol killed the most bacteria followed by alcohol based mouthwash and then the chemical substitute mouthwash.
How many times can you mouthwash in a day?
It is healthy to mouthwash one time per day in addition to using floss and brushing teeth twice a day.
Long term continuous use of mouthwash may erode your teeth enamel and cause staining of your teeth.
According to a study, people using mouthwash twice or more than twice daily had a significantly increased risk of pre-diabetes or diabetes compared to less frequent users or non-users of mouthwash.
Other FAQs about Mouthwash that you may be interested in.
Can mouthwash replace flossing?
Can mouthwash replace brushing
Does Listerine cause sore throat?
References:
- Does mouthwash expire?
- Abed, H. H. (2018). Long-term stability study of chlorhexidine gluconate mouthwash in experimental formula. Mustansiriya Dental Journal, 4(2), 136-143.
- Does mouthwash expire? (2021)
- Dentist in spring hill discusses expired dental products. (2018).
- Jones CG. Chlorhexidine: is it still the gold standard? Periodontology 2000. 1997 Oct;15:55-62. DOI: 10.1111/j.1600-0757.1997.tb00105.x. PMID: 9643233.
- Parabens, 2019
- Joshipura, K. J., Muñoz-Torres, F. J., Morou-Bermudez, E., & Patel, R. P. (2017). Over-the-counter mouthwash use and risk of pre-diabetes/diabetes. Nitric Oxide, 71, 14-20.
- Which mouthwash is more effective in killing oral bacteria. (2016)
- Cury, J. A., Oliveira, M. J. L. D., Martins, C. C., Tenuta, L. M. A., & Paiva, S. M. (2010). Available fluoride in toothpastes used by Brazilian children. Brazilian dental journal, 21, 396-400.
- Can You Use Too Much Of Mouthwash? (2016)