Deficiency correction — parenteral loading
- Reported quantity
- 1000 µg intramuscularly
- Frequency
- Alternate days for 1–2 weeks
- Study duration
- Loading phase, then monthly to three-monthly
This is the standard published loading and maintenance structure.
Protocols · Metabolic
Vitamin B12 (cyanocobalamin / methylcobalamin): literature-reported ranges
B12 has decades of established clinical dosing literature for deficiency and pernicious anaemia. It is included here because it appears constantly as a blend component, where its role and its figures are usually left unstated.
Read this first
Every figure on this page is a range reported in published literature or in a publicly documented study protocol. It is a record of what researchers used, not a recommendation, a therapeutic protocol, or advice. Peptide Intel Hub is an independent publication, sells nothing, and describes these compounds as in-vitro research reagents only.
Compound at a glance
- Class
- Cobalamin vitamin
- Reported half-life
- Days to weeks, depending on hepatic stores
- Routes used in the literature
- Intramuscular, subcutaneous, oral and intranasal
- Also written as
- —
What the published studies reported
Each row below describes one body of work. The model and population are part of the figure — a rodent per-kilogram quantity and a human trial quantity are not comparable.
High-dose oral studies
- Reported quantity
- 1000–2000 µg orally
- Frequency
- Once daily
- Study duration
- 4 weeks to 4 months
Passive diffusion at high oral quantities bypasses intrinsic-factor dependence.
Reconstitution maths
Supplied as a ready-made solution, typically 1000 µg/mL, so 1 mL draws 1000 µg. No reconstitution is needed.
Open the reconstitution calculatorHow to read these figures
- Cyanocobalamin, methylcobalamin and hydroxocobalamin differ in retention and are not equivalent milligram for milligram.
- In blends, B12 often accounts for the colour of the solution and nothing else.
- Correcting B12 without checking folate status is a documented pitfall in the clinical literature.
Sources and citations
These are the published records the figures on this page are drawn from. Each one describes what researchers administered, in which model or population, and over what period. Quantities reported in a study are specific to that study's design and are not transferable guidance.
- [1]Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency: a systematic review of randomized controlled trials
Butler CC, Vidal-Alaball J, Cannings-John R, et al. · Fam Pract · 2006 · PMID 16585128
Systematic review of RCTs comparing intramuscular vitamin B12 injection regimens (e.g., 1000 mcg doses) against oral high-dose B12 for treating deficiency.
View the record - [2]Maintenance Treatment of Pernicious Anaemia by Massive Parenteral Doses of Vitamin B12 at Intervals of Twelve Weeks
Kinloch JD, et al. · BMJ · 1960 · DOI 10.1136/bmj.1.5166.99
Patients with pernicious anemia received large parenteral vitamin B12 doses at 12-week intervals to establish an effective maintenance dosing interval.
View the record - [3]Comparing the Efficacy and Tolerability of a New Daily Oral Vitamin B12 Formulation and Intermittent Intramuscular Vitamin B12 in Normalizing Low Cobalamin Levels: A Randomized, Open-Label, Parallel-Group Study
Castelli MC, Friedman K, Sherry JH, et al. · Clin Ther · 2011 · PMID 21600388
Patients with cobalamin deficiency were randomized to daily oral B12 versus intermittent intramuscular B12 injections (1000 mcg) to compare normalization of serum levels.
View the record
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All research protocolsPeptide Intel Hub is an independent publication and has no affiliation, ownership or commercial relationship with the suppliers listed. We sell nothing and take no payments — links are editorial references only.