← Vitamin B-12 (Methylcobalamin) overview

Vitamin B-12 (Methylcobalamin) Dosage & Reconstitution Guide

⚠ Do not use B12 injections to self-treat unexplained fatigue without checking your levels; a persistent deficiency has underlying causes that need proper diagnosis. Rapid correction of severe deficiency can lower potassium and should be medically supervised.

Research and educational use only — not medical advice, and not for human consumption. The figures below are summarized from public sources, product labeling, and community reports, and are not a prescription or a substitute for a qualified clinician.

Typical dose
1000 mcg (1 mg) per injection
Route
Intramuscular injection
Frequency
weekly to monthly

Dosing schedule

Phase Dose Notes
Standard dose 1000 mcg 1 mg = ~0.033 mL of the 30 mg/mL solution
Higher clinic dose 2500 mcg 2.5 mg = ~0.083 mL, sometimes used in wellness settings
High dose 5000 mcg 5 mg = ~0.167 mL; excess is largely excreted in urine

Timing & cycling

Any time of day, not tied to meals; morning is common so any mild stimulation does not affect sleep.

Cycle length. Ongoing / continuous - deficiency correction and maintenance are long-term, often lifelong for pernicious anemia, with no fixed on/off cycle.

Storage & handling

This product ships as a ready-to-use solution, so there is no powder to reconstitute. Keep it refrigerated at 2–8 °C, protected from light, and draw each dose straight into an insulin syringe. Swab the stopper before every draw and use a fresh needle each time.

Key points

  • This is a ready-to-use 30 mg/mL solution - no reconstitution, mixing, or bacteriostatic water needed.
  • B-12 is a water-soluble vitamin and nutritional compound, not a peptide.
  • Injected volumes are tiny - a 1000 mcg dose is only about 0.033 mL - so an insulin syringe is used.
  • Excess B12 beyond what the body needs is largely excreted in urine, so more is not necessarily better.
  • Using B12 shots for energy or weight loss when your levels are already normal is a lifestyle use with little supporting evidence.

What to monitor

Serum B12 (with MMA/homocysteine to confirm deficiency), CBC for anemia, and potassium during rapid correction of severe deficiency.

Legal & prescription status

OTC as an oral/sublingual supplement; injectable is typically supplied through wellness clinics or by prescription for medical deficiency.

References

  1. Vitamin B12 Supplementation and Methylcobalamin: Use or Misuse (PMC)
  2. Methylcobalamin in Vitamin B12 Deficiency: To Give or not to Give? (2017)
  3. Diagnosis and Treatment of Cobalamin (B12) Deficiency (2024)

This guide is for research and educational purposes only. It is not medical advice and does not describe a product approved for human use. Always consult a qualified healthcare professional before considering any peptide protocol.