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Do B12 injections go bad? How long is B12 good for after the expiration date? These are questions we hear all the time from readers who buy our methylcobalamin B12 vials. Today, we’re dedicating an entire article to clear up these concerns.
Do B12 Shots Expire?
Yes, B12 can expire. What in the world does not expire at some point? However, B12 does not expire in the same sense milk does. The expiration date on most vitamins marks the period through which potency is guaranteed. So, what happens if you take an expired B12 injection? It does not suddenly become poisonous—just less effective:
Properly stored vitamins are likely safe past their expiration date for up to two years. Water-soluble vitamins, such as B12 and C, are more likely to lose their potency quickly. Expired vitamins will not become poisonous, but rather lose their potency. Exceptions to this rule are if supplements are stored in wet, hot, or humid areas and produce mold. Moldy vitamins should not be consumed.
Shanna Levine, MD, Mount Sinai Hospital
The expiration date on meds is the time limit that the dosage potency is guaranteed. After that time, the potency may be less (but often is not). It is the rare drug (some types of tetracycline) that become toxic if outdated. Nevertheless, a pharmacy can not dispense, and a physician is not supposed to administer a medicine beyond its expiration date.
Dr. Arthur Heller, HealthTap
There is also the risk of bacterial contamination, which increases as the B12 ages. This is because B12 is not a standard medication in the US or UK, so it is often made in small-scale compounding pharmacies rather than in large-scale manufacturing facilities.
Despite that risk, there are still easy ways to extend the shelf life of your B12 injections and keep them in good condition long after their expiration date.
Liquid B12 expires faster than dry B12
Vitamin B12 lasts much longer in dry form, which is why we provide our injectable B12 as a powder. In fact, methylcobalamin B12 is so stable in dry form that it can retain its potency at temperatures as high as 315°C / 600°F.
If you buy your B12 from us, each vial comes with an expiration date of just under a year, since an expiration date is required to be on all vitamins. That date assumes you dissolve the B12 in saline as soon as you receive the vial, whether you choose to store it in the fridge or a cool cabinet. In powder form, however, the B12 can last for years.
The risk of photolysis
Even though B12 is very stable when dry, it is also extremely light-sensitive in liquid form. In other words, it can break down through photolysis (destruction by light) unless you store it properly. This is another reason why we prefer to sell B12 in dry form—it helps protect the vitamin from light and high temperatures during delivery.
For the same reason, we recommend wrapping the vial in aluminum foil immediately after you dissolve the B12 in saline. Our amber glass vials block 66% of light, but foil provides full protection. This step is crucial and helps protect your B12.
Just how quickly do B12 injections expire when exposed to light? If you want to learn more, read our article about the photolysis of B12. The key takeaway is that under normal use—drawing from an aluminum-covered vial into a transparent syringe and injecting within a minute or so—there is nothing to worry about.
How to Keep Your B12 From Going Bad
Bottom line, B12 is extremely stable when dry and can last for many years. Even in liquid form, it will still last a year or two past the “expiration” date, unless it is compromised by mold. In any case, we do not recommend using expired B12 injections at all. Because injectable B12 is so affordable, it is safer to just obtain a fresh supply.
That being said, let’s imagine for a moment that there were no expiration dates. How would you extend the shelf life of your injectable B12? Here are some tips:
- B12 is remarkably stable against both heat and light when dry. Liquid formulations spoil faster, either because of contamination or photolysis. For that reason, buy your injectable B12 in dry form and keep it that way for as long as you can.
- Once you dissolve the B12, wrap the vial in aluminum foil and keep out of sunlight. Store it in the fridge, or in a cool, dark place between 5–25°C / 41–77°F. It’s hard to say exactly how long B12 shots last in the fridge compared with a cabinet, but this should help extend the shelf life of your injectable B12 after opening.
- For antimicrobial protection, avoid rubber closures, which can allow contamination through the hole where the needle passes, and may contain rubber additives. For that reason, we don’t use rubber closures. If you’re using our vial, keep it tightly closed. Use sterile needles, and never place them on a surface before use.
Now, if you follow these tips, is it okay to take expired vitamin B12 injections? Probably, but why risk it? B12 shots are affordable enough that we advise to stay well within the expiration date, and avoiding expired B12 shots whenever possible.
Not worth the risk.