A B12 injection is a shot of vitamin B12, usually cyanocobalamin or hydroxocobalamin, given into a muscle to treat or prevent B12 deficiency.
- Status
- Cyanocobalamin and hydroxocobalamin injections are prescription only [1]; cyanocobalamin injection is FDA-approved [4]
- Oral vs shot
- Cochrane 2018: high-dose oral normalized levels similarly to shots (low-quality evidence) [1]
- Higher-risk groups
- Older adults, pernicious anemia, GI surgery, vegans, metformin and acid reducer users [1]
- Price
- Not confirmed for this page
What B12 injections cost
We could not confirm typical prices for B12 shots at clinics or online programs, or for cyanocobalamin vials at pharmacies, for this page. When you compare, ask whether the price includes the visit, the lab test that shows you need it, and supplies. If a doctor diagnoses a deficiency, ask whether your insurance covers the prescription.
Who needs B12 injections
Unlike NAD+, which has no FDA-approved injection [2], cyanocobalamin injection is an FDA-approved prescription drug. One current DailyMed label, approved through an abbreviated new drug application (ANDA), says it is indicated for vitamin B12 deficiencies due to malabsorption, for example from pernicious anemia or some stomach and bowel diseases and surgeries [4]. The NIH Office of Dietary Supplements lists these groups as more likely to run low [1]:
- Older adults, often because of atrophic gastritis
- People with pernicious anemia
- People with stomach or bowel disease, or after GI surgery including bariatric surgery
- Vegans and some vegetarians
- People taking metformin, proton pump inhibitors or H2 blockers
A blood test confirms a deficiency. If you have no deficiency, our research found no evidence that a B12 shot adds benefit.
Oral B12 vs injections
A 2018 Cochrane review, rated as low-quality evidence, found that high-dose oral B12 normalized blood levels about as well as muscle injections [1]. Some people, such as those with severe absorption problems, may still need shots. Your doctor decides which form and how often.
B12 online and at weight loss clinics
Some weight loss companies list MIC+B12 injections; Eden is one [5]. Some compounded GLP-1s also add B12. In a Sept 2026 warning letter, FDA said Empower Pharmacy's compounded semaglutide with cyanocobalamin was among products that are "essentially copies" of approved drugs, a sign that adding B12 does not make a copy lawful [3]. See compounded semaglutide and compounded tirzepatide.
Methylcobalamin, another form of B12 used in compounding, is on FDA's Category 1 list of bulk substances under evaluation [2]. Compounded drugs are not FDA-approved. FDA does not review them for safety, effectiveness or quality before they are sold.
Before buying from a weight loss program, check its record in our FDA warning letter tracker and reviews such as bmiMD and Eden.
When to get help
Signs of an allergic reaction after an injection, such as hives, swelling of the face, lips or throat, or trouble breathing, need emergency care. Call 911.
Dosing questions
We do not give dosing schedules here. Follow your prescriber's instructions and the pharmacy label, and ask your pharmacist about how much and how often.
More injections: wellness injections hub, NAD+ injections, sermorelin.
Questions people ask
How much do B12 injections cost?
We could not confirm typical clinic, online or pharmacy prices as of Oct 17 2026. B12 injections are prescription drugs [1], so ask whether your insurance covers them if you have a diagnosed deficiency.
Do I need a prescription for B12 injections?
Yes. The NIH Office of Dietary Supplements lists cyanocobalamin and hydroxocobalamin injections as prescription products [1].
Are B12 injections FDA-approved?
Cyanocobalamin injection is. A current DailyMed prescription label, approved through an abbreviated new drug application, lists it for vitamin B12 deficiencies due to malabsorption, such as from pernicious anemia [4]. Compounded B12 blends, such as MIC+B12, are not FDA-approved, and FDA does not review compounded products for safety, effectiveness or quality [6].
Are B12 pills as good as B12 shots?
A 2018 Cochrane review, with low-quality evidence, found high-dose oral B12 normalized blood levels about as well as muscle injections [1]. Your doctor decides which suits you.
Who is most likely to need B12?
Older adults, people with pernicious anemia, people with GI disease or surgery including bariatric surgery, vegans, and people taking metformin, proton pump inhibitors or H2 blockers [1].
Why is B12 added to compounded semaglutide or tirzepatide?
Some pharmacies add B12 to compounded GLP-1s. In a Sept 18 2026 warning letter, FDA said Empower Pharmacy's compounded semaglutide with cyanocobalamin was among products that are "essentially copies" of approved drugs [3].
Can I get B12 injections online?
Some weight loss telehealth companies sell MIC+B12 injections. B12 injections are prescription drugs [1], so a prescriber must be involved. Check the company's FDA letter record first.
Sources
6 cited
- Vitamin B12 fact sheet for health professionals. NIH Office of Dietary Supplements, Jul 2, 2025.
- Bulk drug substances nominated for use in compounding under section 503A (category lists). US Food and Drug Administration, May 14, 2026.
- Warning letter: Empower Clinic Services dba Empower Pharmacy. US Food and Drug Administration, Sep 18, 2026.
- Cyanocobalamin injection label (Hikma Pharmaceuticals USA), human prescription drug label, ANDA. DailyMed, US National Library of Medicine, accessed 2026-10-17.
- Eden home page. Eden, accessed 2026-10-17.
- Compounding and the FDA: questions and answers. U.S. Food and Drug Administration, 2025-09-16 (accessed 2026-10-17).
This page is general information, not medical advice. Talk with a licensed clinician about your own care.