What the FDA labels say about taking them together
Cyanocobalamin and hydroxocobalamin
Cyanocobalamin's FDA label (Nascobal) of March 1, 2024 names hydroxocobalamin in its warnings and precautions section, and hydroxocobalamin's label names cyanocobalamin too. The hydroxocobalamin label: “… available, in patients with known anaphylactic reactions to hydroxocobalamin or cyanocobalamin. Risk of Renal Injury:”
Check it at the source: the cyanocobalamin FDA label on DailyMed (effective October 31, 2023, American Regent, Inc.); the hydroxocobalamin FDA label on DailyMed (effective January 31, 2017, Actavis Pharma, Inc.).
What does the cyanocobalamin label say about hydroxocobalamin?
Nascobal label (Par Health USA, LLC, March 1, 2024), warnings and precautionsFor patients with Leber’s disease requiring vitamin B 12 , consider alternative therapy (e.g., hydroxocobalamin) for B 12 supplementation.
Source: FDA drug label (Nascobal, NDA021642), Par Health USA, LLC, effective March 1, 2024 (SPL set 697e0e52-c01b-4b53-9994-f79c46eb6b4f), via openFDA
Source: FDA drug label (Cyanocobalamin), American Regent, Inc., effective October 31, 2023 (SPL set 2fb653d6-e2b2-4969-831b-c0dc37b9c0cc), via openFDA; the full label on DailyMed
What does the hydroxocobalamin label say about cyanocobalamin?
Cyanokit label (BTG INTERNATIONAL INC., April 27, 2023), warnings and precautionsWARNINGS AND PRECAUTIONS Risk of Anaphylaxis and Other Hypersensitivity Reactions: Consider alternative therapies, if available, in patients with known anaphylactic reactions to hydroxocobalamin or cyanocobalamin. ( 5.2 ) Risk of Renal Injury:
Source: FDA drug label (Cyanokit, NDA022041), BTG INTERNATIONAL INC., effective April 27, 2023 (SPL set d56fcc8d-bd64-46ab-b0c0-2124bd745a6b), via openFDA
Source: FDA drug label (Hydroxocobalamin), Actavis Pharma, Inc., effective January 31, 2017 (SPL set a3087a39-f218-4f16-a1e7-17c39bb2eb69), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Cyanocobalamin | Hydroxocobalamin | |
|---|---|---|
| Labeled for | Anemia | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $1.47 per mL 1,000 mcg/mL vial | $0.814 per mL 1,000 mcg/mL |
| Shortage now | No current entry | In shortage |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once