Multivitamins are quite possibly the most popular dietary supplement on the market -- even individuals who don’t consider themselves regular supplement “users” typically take a daily multivitamin.
A recent survey found that about 75% of U.S. citizens consume some sort of dietary supplement. 
Still, many questions abound regarding the utility and safety of multivitamins. One of the most common questions about supplements is: "is it safe to take expired multivitamins?"
Because, let's face it, we've all loaded up on those BOGO deals at one time or another, and invariably a product ticks past its due date before we get around to using it.
So, what’s the verdict?
Are expired vitamins and other dietary supplements safe to take?
Do Vitamins Expire?
Before we answer that question, let’s first start by discussing -- what does an expiration date mean?
Quite simply, the expiration date is the final day that the manufacturer guarantees the full potency and safety of a product. Expiration dates exist on most packaged goods, including prescription medications, over-the-counter (OTC) products, and dietary supplements. 
That being said, vitamins don't "expire" in that same sense that food expires...you know what we're talking about. You left that tub of cottage cheese or pack of chicken in the fridge too long, and it started growing all kinds of phosphorescent goodness.
When a vitamin "expires," it doesn't become hazardous to ingest (as is the case with food that's way past its expiration date). Vitamins (and other dietary supplements) past their expiration date become less potent.
This is because the ingredients in vitamins (as well as other dietary supplements) eventually break down, meaning they become less effective over time.
What is the Average Shelf Life for Vitamins?
The shelf-life of a vitamin depends on a number of factors, including:
- Forms of minerals used
- Delivery form of the multivitamin
- Storage conditions (ambient temperature, humidity, etc.)
Other factors that can affect the shelf life of vitamins include:
- pH levels
- Exposure to oxygen
- Exposure to light
- Extreme temperatures
Interestingly, unlike prescription and over-the-counter (OTC) medications, the U.S. Food and Drug Administration (FDA) doesn’t require vitamin and dietary supplement manufacturers to include an expiration date on the packaging.
However, most companies will (voluntarily) provide a "best before" or "use by" date on the container of the supplement.
All that being said, the average shelf life for vitamins is about two years (from when they’re produced, not from when you purchase them). Also, keep in mind that this shelf life depends on the type of multivitamin and the conditions to which it is exposed and stored.
It’s worth noting that gummies and chewable vitamins typically absorb more moisture than vitamins in tablet or capsule form. Due to this, gummies and chewables generally degrade faster.
However, when stored properly, vitamins in tablet form can retain their potency for several years.
Is It Safe to Take Vitamins That Have Expired?
Generally speaking, experts note that taking an expired supplement (including vitamins) is highly unlikely to cause harm.
As we said above, vitamins don’t go “bad” in the same sense that fresh food does, nor do vitamins (or other supplements) become toxic or poisonous.
Furthermore, and the publication of this article, there aren't any documented cases in the scientific literature of illness or other serious adverse effects resulting from the ingestion of expired vitamins.
Also, keep in mind that expiration dates on dietary supplements are very conservative to ensure consumers receive only the highest quality products. However, if you're looking for the optimal potency of your supplement, it's best to use it before the expiration date.
Note: this is why anecdotal accounts typically report that pre-workout supplements past their expiration date tend to not "hit" as hard as they did during their prime.
On a closing note, medical experts have stated that expired medicine is safe to take, even those many years past its expiration. Yes, the effectiveness of a pharmaceutical can decrease over time, but much of the original potency remains after ten years past the expiration! 
Notable exceptions to this (outlined by researchers) include liquid antibiotics and insulin. 
Lastly, tablets and capsules appear to be most stable past their expiration date. 
How to Store Vitamins
To ensure the maximum shelf life (and therefore, potency) of your multivitamin, best practices would be to store them in their original container in a cool, dry place out of direct sunlight.
Ideally, you’d store your multivitamin, such as Steel Multi-V®, in a linen closet or bedroom drawer... or some other place in the house that isn’t humid, hot, or exposed to lots of direct sunlight.
Additionally, keep in mind that specific fat-soluble vitamins — like vitamins A and D — will lose their potency after prolonged exposure to light.
Along those same lines, keep your vitamins out of the kitchen or bathroom, as these rooms typically are affected by both heat and moisture -- which can contribute to quicker degradation of vitamins and other dietary supplements.
Keep in mind, though, that you should read instructions on our supplement for recommended storage.
Instructions may differ between supplements.
For example, many individuals choose to refrigerate or freeze their fish oil supplements to reduce the chance of tasting "fishy." However, some fish oil supplements specifically note that they shouldn't be stored below 60 degrees.
Vitamins and other supplements will lose potency over time, especially if they are past their expiration or “use best by” date.
However, just because a vitamin (or other dietary supplement) is past its “best by” date does not mean it’s toxic or hazardous -- it simply may not pack the same “punch” as it used to.
If you have questions about your particular multivitamin (or dietary supplement), don’t hesitate to contact the company from which you purchased the product.
- Dietary supplement use reaches all time high. (n.d.). Council for Responsible Nutrition. https://www.crnusa.org/newsroom/dietary-supplement-use-reaches-all-time-high
- Gikonyo D, Gikonyo A, Luvayo D, Ponoth P. Drug expiry debate: the myth and the reality. Afr Health Sci. 2019;19(3):2737-2739. doi:10.4314/ahs.v19i3.49