This grade answers one narrow question: how strong is the public evidence and safety record behind this drug, and how clean is its money trail and court record? It is not a verdict on whether the drug is right for you.
is indicated for: Vitamin B 12 maintenance therapy in adult patients with pernicious anemia who are in remission following intramuscular vitamin B 12 therapy and who have no nervous system involvement Treatment of adult patients with dietary, drug-induced, or malabsorption-related vitamin B 12 deficiency not due to pernicious anemia Prevention of vitamin B 12 deficiency in adult patients with vitamin B 12 requirements in excess of normal Limitations of Use NASCOBAL should not be used for the vitamin B 12 absorption test (Schilling test). In patients with correctible or temporary causes of vitamin B 12 deficiency, the benefit of continued long-term use of NASCOBAL following adequate correction of vitamin B 12 deficiency and underlying disease has not been established. The effectiveness of NASCOBAL in patients with active symptoms of nasal congestion, allergic rhinitis or upper respiratory infection has not been determined. Treatment with NASCOBAL should be deferred until symptoms have subsided. NASCOBAL is a vitamin B 12 indicated for: Vitamin B12 maintenance therapy in adult patients with pernicious anemia who are in remission following intramuscular vitamin B12 therapy and who hav...
is contraindicated in patients with hypersensitivity to cobalt and/or vitamin B 12 or any of its excipients [see Warnings and Precautions (5.2) ] . Anaphylactic shock and death have been reported after parenteral vitamin B12 administration in sensitive patients. • Hypersensitivity to cobalt, vitamin B 12 or any excipients (4)
• Severe Optic Atrophy in Patients with Leber’s Disease : Patients with early Leber’s disease who were treated with vitamin B 12 suffered severe and swift optic atrophy. NASCOBAL is not recommended for use in these patients.(5.1) • Anaphylactic Reactions: Anaphylactic shock and death have been reported after parenteral vitamin B 12 administration. If patients are to start NASCOBAL before having tolerated cyanocobalamin parenterally, consider administering an intradermal test dose of parenteral vitamin B 12 to patients suspected of cyanocobalamin hypersensitivity. (2.1,5.2) • Masking of Folate Deficiency with Vitamin B 12 Use: Doses of vitamin B 12 exceeding 10 mcg daily may produce hematologic response in patients with folate deficient megaloblastic anemia and may therefore mask a previously unrecognized folate deficiency. Assess both vitamin B 12 and folate levels prior to initiating therapy with NASCOBAL or with folic acid. (5.3) • Hypokalemia and Thrombocytosis Due to Intense Treatment of Megaloblastic Anemia: Hypokalemia and sudden death may occur in severe megaloblastic anemia that is treated intensely with vitamin B 12 . Monitor serum potassium levels and platelet count durin...
The following serious adverse reactions are described elsewhere in the labeling: Severe Optic Atrophy in Patients with Leber’s Disease [see Warnings and Precautions (5.1) ] . Anaphylactic Reactions [see Warnings and Precautions (5.2) ] . Hypokalemia and Thrombocytosis Due to Intense Treatment of Megaloblastic Anemia [see Warnings and Precautions (5.4) ] . The most common adverse reactions (≥ 4%) were infection, headache, glossitis, paresthesia, asthenia, nausea and rhinitis (6.1) To report SUSPECTED ADVERSE REACTIONS, contact Endo at 1-800-828-9393 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . See 17 for PATIENT COUNSELING INFORMATION and FDA-approved patient labeling 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The adverse reactions described in Table 1 below are based on data from an eight week cross over trial in which vitamin B12 deficient patients in hematologic remission received one vitamin B12 intramuscular injection (N=25)...
Source: FDA SPL label for Nascobal (Par Health USA, LLC), effective 20240301. Full label on DailyMed.
These are counts of reports people filed, not rates of harm. Anyone can file one, and nobody checks whether the drug was the cause. Millions of doses are taken for every report sent, so the useful part is how this drug compares with the average across all drugs.
| 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 | 2026 |
|---|---|---|---|---|---|---|---|
| 12,316 | 12,911 | 11,311 | 11,533 | 10,741 | 10,740 | 11,574 | 5,821 |
Source: the FDA's Adverse Event Reporting System (FAERS). Reports are voluntary and unverified. Drugs that are prescribed a lot, in the news, or in lawsuits attract more reports, so the percentages are compared with the whole database to correct for that partly, not fully.
| Date | Class | Firm | Reason |
|---|---|---|---|
| 07/2026 | Class II | American Regent, Inc. | Presence of Particulate Matter: Product contaminated with particulate matter identified as hair, glass and/or paraformaldehyde |
| 07/2026 | Class II | American Regent, Inc. | Presence of Particulate Matter: Product contaminated with particulate matter identified as hair, glass and/or paraformaldehyde |
| 04/2022 | Class III | Aurobindo Pharma USA Inc. | Subpotent Drug: Out of Specification results for Assay |
| 03/2021 | Class II | Cardinal Health Inc. | CGMP Deviations: Intermittent exposure to temperature excursion during storage. |
| 09/2012 | Class II | Fresenius Kabi USA, LLC | Lack of Assurance of Sterility: Glass vials may have finish fractures and glass particles. |
Class I = reasonable probability of serious harm. Class II = temporary or reversible harm. Class III = unlikely to harm. Most generic recalls are manufacturing or labeling defects for one lot, not a verdict on the molecule.
Counts measure how much evidence exists and how transparent it is, not how big the benefit is. For that, ask your prescriber: if 100 people like me took this, how many would get better because of it, and how many would be harmed? (Doctors call these the "number needed to treat" and "number needed to harm.") It differs by condition and is the number drug ads leave out. Sources: PubMed, ClinicalTrials.gov.
In 2024, drug companies reported $1,099 in payments to US physicians and hospitals tied to this drug across 62 transactions (Nascobal $1,099).
No pending federal MDL names this drug or its brands.
Not named in any federal pharmaceutical settlement of $100M or more on record.
Sources: CMS Open Payments (Sunshine Act); Judicial Panel on Multidistrict Litigation pending docket list; DOJ settlements as tabulated on Wikipedia with links to the primary record. State-court and individual suits are not included.
Not in the Medicare Part D spending file (typically hospital-administered or very new drugs).
Same ATC pharmacological class, graded ones first, best grade at the top. Being in the same class does not make them interchangeable for your condition; it makes them worth asking about.