Can you overdo B12 injections?

Since B12 is a water-soluble vitamin, it's generally considered safe, even at high doses. No Tolerable Upper Intake Level (UL) has been established for B12, due to its low level of toxicity.


How much B12 can you inject daily?

For B12 Deficiency

If you have a vitamin B12 deficiency, the initial dose is usually 30mcg injected under the skin or into the muscle every day for between 5 and 10 days to boost levels of B12 quickly. For maintenance, it is common to have monthly therapy of 100-200 mcg.

How often should I give myself B12 injections?

This is usually given as an intramuscular injection, every 2-3 months. Alternatives to an intramuscular injection are: Oral Vitamin B12 at a dose of at least 1000mcg per day.


How quickly do B12 injections wear off?

Generally, the results of vitamin B12 injections can last about one week, but it is vital to have this administered by a healthcare provider. Also, the healthcare provider will determine the appropriate B12 dosage, depending on the current medical condition and diet.

How long does a B12 injection last in your body?

Simply put, how long the B12 shot will last is different for everyone. Though it differs a bit from one person to another, the effects of B12 vitamins usually last around 48 hours to 72 hours after the initial injection.


Are Vitamin B12 Injections Worth Your Money?



Why do I feel tired after B12 injection?

More Serious Effects

B12 injections may contribute to low potassium levels in your body. Though rare, this reaction can cause muscle cramping, extreme fatigue, and an irregular heartbeat.

How do you feel after B12 shot?

What to expect after getting a B12 shot? Pain/redness at the injection site, mild diarrhea, itching, or a feeling of swelling all over the body may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

How long does it take for B12 to start working?

It may take a few weeks before your vitamin B12 levels and symptoms (such as extreme tiredness or lack of energy) start to improve. If you have hydroxocobalamin injections to boost your vitamin B12 levels at the start of treatment, the cyanocobalamin tablets may start to work within a few days.


What medications should not be taken with B12?

As summarized in the table provided, vitamin B12 (cobalamin) absorption and utilization by the body can be compromised with the chronic use of certain medications which include: colchicine, chloramphenicol, ethanol, histamine 2 receptor antagonists (H2RA), metformin, and proton pump inhibitors (PPI).

Do B12 injections always work?

Vitamin B12 Shots Are Very Effective

Injections are usually given as hydroxocobalamin or cyanocobalamin. These are very effective at raising blood levels of B12 and preventing/reversing a deficiency. Bottom Line: If you are deficient in vitamin B12, then the injections are very effective at raising your blood levels.

How much B12 injection for weight loss?

In one clinical trial assessing the efficacy of phentermine and vitamin B-12 for weight loss, vitamin B-12 (as the sole ingredient) was administered via injections of 1,000 mg per week. Regardless of the dosage, your practitioner will likely recommend weekly shots for several weeks.


What should you not do after a B12 shot?

Avoid strenuous exercise for 48 hours after your treatment. Avoid touching the injection site for 6 hours after your treatment. You may experience a dull ache at the injections site for around 1 hour after your treatment. Avoid any blood thinning medication.

How do I know if B12 injections are working?

B12 injections work quickly; they are the most effective way for your body to absorb Vitamin B12. Within 48 to 72 hours, your body will begin to make new red blood cells. For mild deficiencies, you may need two to three injections over several weeks to notice peak impact.

What are the symptoms of high B12 levels?

High doses of vitamin B-12, such as those used to treat a deficiency, might cause:
  • Headache.
  • Nausea and vomiting.
  • Diarrhea.
  • Fatigue or weakness.
  • Tingling sensation in hands and feet.


Can B12 cause exhaustion?

Fatigue. If you're low or deficient in B12, you'll likely feel fatigued. Your body's cells need B12 to function properly. As such, having inadequate B12 levels can decrease normal red blood cell production, which can impair oxygen delivery ( 8 ).

Does B12 injections have side effects?

Pain/redness at the injection site, mild diarrhea, itching, or a feeling of swelling all over the body may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

What are the positive effects of B12 injections?

Vitamin B12 shots can help boost your body's energy levels by preventing fatigue, helping you to lose weight and also by lowering the risk of heart disease and other serious health concerns. Vitamin B12 is also essential for the health of your skin, hair and nails.


Where is the best place to inject B12?

For intramuscular injections, the common sites for B12 injections are the arm, upper buttocks, and thigh. Subcutaneous injections can be administered at the side or back of the upper arm, lower abdomen, and front of the thigh.

Why are NHS stopping B12 injections?

Many doctors' surgeries and health centres have closed due to the current Covid-19 pandemic. This has meant that many of our members are unable to get their live-saving injections of B12.

Should you take B12 shot in the morning or at night?

Vitamin B12, for example, should definitely be taken in the morning. This is because it is important for energy metabolism, which may interrupt your sleep if taken at night.


Do you gain weight with B12 injections?

Vitamin B12 can help with promoting weight loss and has been linked to weight loss.

What happens if your B12 is too high?

In some people, high levels of B12 may cause gastrointestinal problems such as bloating and diarrhea. And if you have high blood pressure or poor cardiovascular health, having too much B12 may further complicate these issues. Pregnant and breastfeeding women may also need to be especially mindful of B12 levels.

Can B12 cause neuropathy?

B12 deficiency may cause demyelination of nerves in the peripheral and central nervous system13 and has been associated with peripheral neuropathy, loss of sensation in peripheral nerves, and weakness in lower extremities in older adults1, 1416.


Can too much B12 cause neuropathy?

Symptoms of neuropathy usually stop when the supplements are discontinued. High-dose vitamin B supplements should be avoided, because they can lead to nerve damage.

Does B12 affect your eyes?

Disturbed or blurred vision can also occur as a result of a Vitamin B12 deficiency. This happens when the deficiency causes damage to the optic nerve that leads to your eyes. The nervous signal that travels from the eye to the brain is disturbed due to this damage, leading to impaired vision.