Vitamin B12
cyanocobalamin · hydroxocobalamin · methylcobalamin
A vitamin available as an injectable medicine for a shortage. Injections for energy or weight loss are a different use.
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- Type
- Nutrient
- Stage
- Approved medicine
- Safety
- Well known
- Risk of fakes
- Not known
- Checked
- Not yet
Doping. The substance is not on the WADA list, but drips and injections above 100 mL in 12 hours are banned, except in hospital care and medical tests.
Safety. An old medicine with a US label. The label describes severe damage to the optic nerve in people with early Leber disease, a rare eye condition. Sources: US drug label.
Risk of fakes. We found no tests of products sold outside pharmacies.
Is it legal
| Where | Status | Checked | |
|---|---|---|---|
| PL | Approved medicine | Approved as Vitaminum B12 Wzf and Sf injections, and as Cobalaxin and Energamma by mouth (European medicines database, EMA, 9 October 2026). Source | Not yet |
| EU | Approved medicine | Separate national medicines in 31 countries of the European medicines database, EMA (9 October 2026). Source | Not yet |
| US | Prescription only | Prescription medicine (cyanocobalamin). Source | Not yet |
How much research exists
Scientific papers per year 2015–2025
These are search results. A count shows how much exists, not how good the studies are. 1 Nov 2026.
Reported side effects
What doctors, patients and companies reported to the US medicines agency (FDA), and single cases described in medical journals. A report says what happened to someone after taking the substance. It does not prove the substance caused it, and it does not say how often it happens. Reports do not change any grade.
Cases described in medical journals
- Potential role of vitamin B12 supplementation in neurological recovery after severe traumatic brain injury.
- Systemic Allergic Dermatitis Induced by Intramuscular Vitamin B12 Administration.
- Intravenous Methylcobalamin-Induced Anaphylactic Shock: A Case Report.
- Metformin-Associated Functional Vitamin B12 Deficiency Presenting as Subacute Combined Degeneration in a 57-Year-Old Man With Diabetes Mellitus.
- Fewer injections, less pain: Successful cyanocobalamin desensitization.
- Severe Vitamin B12 deficiency with complications in an elderly patient: a case study of pancytopenia and haemolysis.
FDA reports come from openFDA, cases from a PubMed search. The editors have not read these cases yet. Titles stay in the original language. As of 3 Nov 2026.
More papers we found
We found these papers automatically in PubMed. The editors have not read them yet, and they do not affect any grade. Titles stay in the original language.
Short answers
- Does Vitamin B12 work?
- A vitamin available as an injectable medicine for a shortage. Injections for energy or weight loss are a different use. We have not graded the studies yet. The number of papers in the databases is shown on the page.
- Is Vitamin B12 legal?
- PL: Approved medicine. Approved as Vitaminum B12 Wzf and Sf injections, and as Cobalaxin and Energamma by mouth (European medicines database, EMA, 9 October 2026). EU: Approved medicine. Separate national medicines in 31 countries of the European medicines database, EMA (9 October 2026). US: Prescription only. Prescription medicine (cyanocobalamin).
- Is Vitamin B12 banned in sport?
- Not on the list, WADA 2026. The substance is not on the WADA list, but drips and injections above 100 mL in 12 hours are banned, except in hospital care and medical tests.
- Is Vitamin B12 safe?
- Well known. An old medicine with a US label. The label describes severe damage to the optic nerve in people with early Leber disease, a rare eye condition.