How do you take Cyanocobalamin?

For tablets, the usual adult dose is 50 to 150 micrograms (mcg) daily, taken with or without food. For injections, your doctor or nurse will give you 1,000 mcg by injection, usually once daily or every other day at first, then once a month for maintenance. Follow whatever your doctor prescribes based on your specific condition.

What are the side effects of Cyanocobalamin?

Mild diarrhoea or stomach upset, headache, feeling of swelling in the body, itching or mild rash at the injection site, slight dizziness

Who should not take Cyanocobalamin?

People who are allergic to cyanocobalamin or cobalt should not take this drug. People with Leber's disease (a hereditary eye condition) should avoid it as it can cause serious eye damage. If you have polycythaemia vera (a condition where you produce too many red blood cells), do not use without a doctor's supervision.

OTC

Vitamin (B12 supplement)

Cyanocobalamin

Q: What is Cyanocobalamin used for?

Vitamin B12 deficiency, anaemia (low blood), tingling or numbness in hands and feet, tiredness and weakness, poor appetite, mouth sores (glossitis)

Last reviewed July 2026

Who is this for?

For adults (18+). Standard adult dosing applies: see the How to Take tab for full instructions.

What is this drug?

Cyanocobalamin is a man-made form of Vitamin B12, an essential vitamin your body needs to make healthy red blood cells, keep your nerves working properly, and produce energy from the food you eat.

How it works

Restores cobalamin cofactor pools essential for methylmalonyl-CoA mutase and methionine synthase, enabling normal DNA synthesis, myelin formation, and erythropoiesis while correcting neurological and haematological manifestations of B12 deficiency.

What is it used for?

Vitamin B12 deficiencyanaemia (low blood)tingling or numbness in hands and feettiredness and weaknesspoor appetitemouth sores (glossitis)

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Vitamins & Supplements Anaemia

Available Over The Counter

Get this from any pharmacy or chemist: no prescription needed.

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What to watch out for

Only buy from registered pharmacies, avoiding vitamin injections from roadside vendors or market sellers, as fake or expired products are common. Do not self-inject at home unless trained by a health professional. If you have been feeling unusually tired or weak for a long time, get a proper blood test before assuming you just need vitamins.

Common Side Effects

Mild diarrhoea or stomach upset
headache
feeling of swelling in the body
itching or mild rash at the injection site
slight dizziness

Serious Side Effects

Severe allergic reaction (difficulty breathing, swelling of the face or throat, serious rash): go to the hospital immediately. Sudden chest pain
fast heartbeat
or swelling in your legs could mean a serious problem
so seek medical help right away.

Drug Interactions

Metformin (commonly used for diabetes) can reduce how well your body absorbs Vitamin B12, so tell your doctor if you take it. Chloramphenicol (an antibiotic) can reduce the effectiveness of cyanocobalamin. Heavy alcohol drinking over time can lower your Vitamin B12 levels and make treatment less effective.

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Pregnancy & Breastfeeding Warning

Cyanocobalamin is generally considered safe during pregnancy and breastfeeding, but always consult your doctor to confirm the right dose for you.

Who Should NOT Take This

People who are allergic to cyanocobalamin or cobalt should not take this drug. People with Leber's disease (a hereditary eye condition) should avoid it as it can cause serious eye damage. If you have polycythaemia vera (a condition where you produce too many red blood cells)
do not use without a doctor's supervision.

How to Store

Store tablets in a cool, dry place away from direct sunlight and heat. Nigerian weather can be very hot, so avoid storing near windows or in your car. Keep injections in a refrigerator if instructed, or at room temperature away from light. Always keep out of the reach of children.

For information only: not medical advice. Always talk to a doctor or pharmacist before changing your medication.