Hydroxocobalamin Is a Form of Vitamin B12 Given by Injection to Treat B12 Deficiency, Pernicious Anemia, and Cyanide Poisoning

If your doctor has mentioned Hydroxocobalamin — or you've seen it on a prescription — you probably have questions. What exactly is it? How is it different from the B12 supplements you can buy at the store? And why does it need to be injected?

This guide covers everything you need to know about Hydroxocobalamin in 2026, from what it's used for to how much it costs.

What Is Hydroxocobalamin?

Hydroxocobalamin is a vitamin B12 analog — a form of vitamin B12 that your body converts into its active forms (methylcobalamin and adenosylcobalamin). It belongs to the drug class of anti-anemic agents and is also classified as a cyanide antidote.

Here are the key details:

• Generic name: Hydroxocobalamin
• Brand names: Cyanokit (IV form for cyanide poisoning), Hydroxy-Cobal, Hydro-Cobex, Cobalin-H
• Drug class: Vitamin B12 analog / Anti-anemic agent / Cyanide antidote
• Manufacturer: Serb Pharmaceuticals (Cyanokit); Hikma Farmaceutica / Actavis Pharma (generic IM injection)
• FDA-approved: Yes
• Controlled substance: No — Hydroxocobalamin is not a controlled substance and has no DEA schedule
• Generic available: Yes

You may also see it referred to as Hydroxocobalamin Acetate, Hydroxycobalamin, vitamin B12a, or simply "B12 shot."

What Is Hydroxocobalamin Used For?

FDA-Approved Uses

• Vitamin B12 deficiency — The most common reason it's prescribed. B12 deficiency can cause fatigue, weakness, numbness, tingling in the hands and feet, memory problems, and mood changes.
• Pernicious anemia / macrocytic anemia — A condition where your body can't absorb enough B12 from food, leading to a shortage of healthy red blood cells.
• Cyanide poisoning — The IV form (Cyanokit, 5 grams) is used in emergency settings to treat known or suspected cyanide poisoning, such as from smoke inhalation in fires.

Off-Label Uses

Doctors sometimes prescribe Hydroxocobalamin for conditions not listed on the FDA label, including:

• Peripheral neuropathy from B12 deficiency
• Nutritional optic neuropathy (tobacco amblyopia)
• Leber optic atrophy
• Nitroprusside-induced cyanide toxicity
• Post-gastric surgery B12 supplementation
• Fatigue and energy support (through wellness and integrative medicine clinics)

How Is Hydroxocobalamin Taken?

Hydroxocobalamin is not available as a pill. It's given by injection:

• Intramuscular (IM) injection — For B12 deficiency. The standard formulation is a 1,000 mcg/mL solution in a 30 mL multi-dose vial. Your doctor or nurse gives the injection into a muscle, usually the upper arm (deltoid) or outer thigh.
• Intravenous (IV) infusion — For cyanide poisoning only. The Cyanokit contains 5 grams of Hydroxocobalamin given IV over 15 minutes in a hospital setting.

Typical Dosing for B12 Deficiency

The standard treatment schedule is:

1. Loading phase: 1,000 mcg (1 mg) injected every other day for 5 to 10 doses
2. Maintenance phase: 1,000 mcg injected every 1 to 3 months

Many patients learn to self-inject at home after training from their healthcare provider. This saves you from frequent office visits and gives you more flexibility. Your doctor or nurse can show you the proper technique.

Compounding pharmacies may also offer Hydroxocobalamin in higher concentrations (10 mg/mL or 20 mg/mL) for patients who prefer smaller injection volumes.

Who Should Not Take Hydroxocobalamin?

Hydroxocobalamin has very few absolute contraindications:

• Allergy to Hydroxocobalamin, Cyanocobalamin, or cobalt — If you've had an allergic reaction to any form of B12 or to cobalt, do not take Hydroxocobalamin.

Your doctor should use caution if you have:

• High blood pressure (hypertension)
• Heart disease or heart failure
• Liver disease
• Kidney disease

For cyanide poisoning, there are essentially no contraindications — the benefits of treating cyanide poisoning always outweigh the risks.

If you're pregnant or breastfeeding, talk to your doctor. Hydroxocobalamin is FDA Pregnancy Category C, meaning the risks aren't fully known, but your doctor may determine the benefits outweigh the risks in your case.

How Much Does Hydroxocobalamin Cost?

Cost depends on which formulation you need and whether you have insurance:

• Generic IM injection (1,000 mcg/mL, 30 mL vial): $20 to $60 at retail pharmacies. With a GoodRx coupon, prices can be as low as $20.86.
• Cyanokit (5 g IV kit for cyanide poisoning): $3,400 to $4,300 — this is used only in hospital emergency settings and is typically covered by your insurance or the hospital.

Most insurance plans cover generic Hydroxocobalamin IM injections with low copays. Prior authorization is generally not required, though your insurer may want documentation of B12 deficiency through blood work.

For more ways to lower your costs, check out our guide on coupons, discounts, and patient assistance for Hydroxocobalamin.

Is There a Hydroxocobalamin Shortage?

Yes. As of early 2026, Hydroxocobalamin is in an active shortage. The generic IM injection from Hikma/Actavis has been temporarily unavailable since December 2025 due to a shortage of the active ingredient. Resupply is estimated for June 2026.

If you're having trouble finding it, use Medfinder to check pharmacy stock in your area, or learn how to check if a pharmacy has it in stock. You can also talk to your doctor about alternative B12 options.

Final Thoughts

Hydroxocobalamin is a safe, effective, and well-established treatment for vitamin B12 deficiency and pernicious anemia. It's been used for decades and is preferred by many doctors because it stays in the body longer than Cyanocobalamin, meaning fewer injections over time.

If you've been prescribed Hydroxocobalamin, the biggest challenge in 2026 may be finding it in stock. But with the right tools and a little persistence, you can get the treatment you need.

Want to understand more about how this medication works in your body? Read our guide on how Hydroxocobalamin works.