The Risks of Using Expired Melatonin and Other Supplements


Buying in bulk is practical, but not for all food products. The consequences of this include foods going stale after a while because you couldn’t consume them fast enough and you getting sick. This also applies to medicines and supplements, like expired melatonin.

Let’s say you bought melatonin to help with your insomnia a few years ago. You only consumed a few pills before your insomnia got better, so you left your melatonin to expire over the next few years. But now that you need melatonin again, you might be considering taking your leftover pills instead of throwing them away and getting a new bottle.

Like food, drinks, and other products made from natural items, consuming things that have already passed their expiry date has serious risks. But does that also include supplements? For this case, let’s use liquid melatonin as an example.

Why Are Expiration Dates Important?

An expiration date is the final day or month where a manufacturer guarantees that their product is still safe to use or consume. Since 1979, the Food and Drug Administration requires all pharmaceutical companies to put expiration dates on their products. Most products, especially medicines (both and over-the-counter and prescription medicines) are required to put an expiration date on their products for safety and legal reasons.

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Safety because they can guarantee that their products will work without harmful side effects. It’s also for legal purposes because the expiration date serves as a disclaimer against consumers who try to sue the manufacturer for any side-effects. If a consumer decides to consume medicine that has passed the expiration date, the manufacturer isn’t liable for the side effects the consumer experiences.

Most drugs and supplements’ expiration dates are arbitrary and are usually dated two or three years after the product was manufactured. However, it is possible that drugs are still safe to consume after the expiration date, but for liability purposes, manufacturers don’t recommend taking medicine past its expiration date or testing how long it can work.

What Happens to Expired Medication

A 2001 study from the American Medical Association (AMA) found that out of 122 drug products, 88 percent of drugs were still potent around 66 months (around 5 and a half years) after its inscribed expiration date.

However, the AMA did not recommend people use these results as an excuse to continue taking drugs and supplements even after its expiration date because certain factors (e.g. preservatives in the drug, temperature, humidity, light, etc.) in the medicine’s storage could affect its actual shelf life. In short, it’s much safer to just follow the inscribed expiration date.

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Regardless of the manufacturer’s inscribed expiration date, once a medicine reaches its expiration date, it starts to lose its potency. If one tablet of paracetamol has enough active substances to reduce fever and body pain effectively, it won’t do the same job after it expires. When it comes to supplements, a capsule of vitamin C won’t have the same potency to give you the number of vitamins you need for the day.

What Happens If I Take Expired Melatonin or Medicine?

As much as possible, you shouldn’t be consuming expired medicine in the first place.

Once a melatonin product or medicine is past its expiration date, it’s not as effective anymore. There will be changes in its strength and chemical composition which could pose a risk to one’s health. In the case of melatonin tablets, the chemicals inside the product could still interact with anticoagulants and other supplements, so best to stay away from it once it has expired.

If this is for injectable medicine, liquid medicine, or medicines for extremely serious diseases like cancer and heart conditions, your expired prescriptions may not have the same potency or may have unwanted side effects, which could lead your condition to worsen. In these cases, it’s best to get a prescription refill instead of risking expired medicine.

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For minor problems such as headaches and common colds, it may be safe to take over-the-counter medicines. However, the potency isn’t as strong and may not provide the immediate relief you’d expect. If stored correctly, over-the-counter medicines can last much longer than the provided expiration date. But if you take expired medicine and find that the medicine has no effects, the active ingredient has lost most of its potency and will have no effect on your condition.

Supplements: Melatonin

But what about vitamins and supplements like melatonin? Melatonin is a natural hormone found in your body, but pharmaceutical companies can now make synthetic melatonin pills in laboratories. It’s mostly used for jet lag, people who work night shift and need to adjust sleeping in the day, and sleeping disorders that prevent people from sleeping (insomnia) or sleeping throughout the night. It is also used by people who are experiencing withdrawal symptoms from smoking and people with other neurological conditions.

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The body is actually affected by the time and sunlight you get. At night, your body automatically produces more melatonin, which makes you sleepy and makes you want to prepare to go to bed. When it’s bright, your body produces less melatonin and can find it harder to sleep. People with sleep disorders often have low amounts of melatonin, so they need to take doses of synthetic melatonin (around one to three milligrams two hours before bedtime) to trigger sleepiness.

What Happens If I Consume Expired Melatonin?

Because melatonin is a supplement, it’s likely you won’t see any side effects, but you may not see any potency either. Even if it is a few months after the expiration date, melatonin supplements only contain a small amount of the hormone (a little goes a long way if you’re trying to fall asleep), so any reduction in the potency might render it completely useless.

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If you don’t want your expired melatonin to go to waste, you might be thinking that if melatonin loses some of its potency, instead of taking the recommended dosage for your needs, you could take a double dosage to compensate for the loss of potency. This is an extremely bad idea. When medicines and supplements lose their potency, there is no certainty how much of its potency is lost. If some medicines lose 50 percent of its potency in a month, others can lose 5 percent in that same time, and there is no way to test what the potency of expired medicine is.

So, if you try double-dosing expired melatonin, there’s no telling if you’re still under-dosing or overdosing. It’s dangerous to try, so it’s best to just throw away your expired melatonin and buy a new bottle with fully potent pills.

What about Other Supplements?

The FDA doesn’t require supplements to add an expiration date, but because a lot of consumers look for one in most edible products, plenty of supplements have a “best before” or “use by” date. However, like medicines, most supplements also have an average shelf life of two years, but this is also a conservative date and some supplements can surpass this depending on its storage conditions.

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Taking expired supplements are unlikely to turn poisonous and can simply reduce in potency as well. However, taking medicine with low potency can be dangerous to your health in the long run. If you’re taking iron supplements due to an iron deficiency, taking expired supplements with a low potency can increase the risk of anemia, which can lead to a number of symptoms, such as chest pain and dizziness.

How to Dispose of Expired Supplements

It’s best not to play with potency and risk under- or overdosing your supplements. If it’s expired or passed the “use by” date, the safest route is to dispose your expired supplements and buy new ones. Avoid flushing down your supplements or throwing each pill in the trash separately as either scenario can contaminate water or expose your supplements to children and animals who might see the supplement and ingest it.

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For supplements that come in a bottle, simply make sure the bottle is tightly sealed before throwing it in the trash. For those kept in traditional pharmaceutical packaging in foil and plastic, seal it in a Ziploc bag or disposable container before throwing it in the trash.

 When consuming expired supplements, it’s highly unlikely that you’re going to be poisoned, but you’re not going to get the full benefits out of it because the medicine has lost its potency. Don’t try to change the dosage to continue consuming expired supplements because you risk developing side effects if you’re taking too much medicine or not getting enough medicine.

About the Author

Medical Disclaimer

The information provided on this website is for general informational purposes only and should not be considered medical advice. The content on the website is not intended to be a substitute for professional medical diagnosis, treatment, or advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.


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