Cyanocobalamin injection is 1000 mcg/mL, sold as 1 mL vials and 10 mL or 30 mL multiple-dose vials. The 30 mL vial looks cheapest until the 28-day clock runs out. Here's how to buy B12 for a clinic without throwing half of it away.
· 4 min read
Written and clinically reviewed by Jacob Fuchs, PharmD
Reviewed on
Cyanocobalamin injection, the B12 shot, is 1000 mcg/mL. One common manufacturer sells it as a 1 mL vial, a 10 mL multiple-dose vial, and a 30 mL multiple-dose vial (American Regent label). It's given intramuscularly or subcutaneously. The label says to avoid the IV route.
The 30 mL vial has the lowest price per milliliter. Whether it's the cheapest one for you depends on one number: how much you use in the 28 days after you open it.
From American Regent's prescribing information (label):
| NDC | Package | What it is |
|---|---|---|
| 0517-0031-25 | 1 mL fill in a 2 mL vial, box of 25 | Smallest unit |
| 0517-0032-25 | 10 mL multiple-dose vial, box of 25 | Mid-size |
| 0517-0130-05 | 30 mL multiple-dose vial, box of 5 | Largest |
Other manufacturers sell similar sizes with different NDCs. Check the label on the product you actually buy.
Because of the 28-day rule. Once a multiple-dose vial is opened, CDC says to date it and discard it within 28 days unless the manufacturer states another date (CDC). That means writing the discard date on it, not the date you opened it (The Joint Commission).
Do the math before you buy:
We walk through the full set of rules in single-dose vs. multiple-dose vials.
Two things on the label are worth knowing (American Regent label):
Neither is a purchasing decision. But your clinicians should know what's in the product you stock, and these warnings are why.
From a licensed wholesaler that gives you DSCSA transaction information and statements. B12 is a prescription injectable like any other, and the same supply-chain rules apply. Here's how to verify a wholesaler in four checks.
Premier Pharma supplies licensed physician offices, clinics, and pharmacies, and every invoice lists the lot number and expiration date for each item. Want to order cyanocobalamin? Contact our team for current availability and pricing. Open a free account. Credential review typically takes 1–2 business days.
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