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Vitamin B12 · IM / SubQ 99%+ Purity Vitamin B12 Injectable
Wellness

Vitamin B12 Injectable

Vitamin B12 (Methylcobalamin) — injectable cobalamin that ensures neurological function, energy metabolism, and methylation cycle integrity with 100% bioavailability.

★★★★☆ 4.7 · 61 verified reviews · See all
$19.00
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🔬 Third-Party Tested
🇨🇦 Ships Canada-Wide
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Key Benefits
  • 100% bioavailability — bypasses gastric intrinsic factor and ileal absorption requirements
  • Neurological protection — myelin synthesis and neuronal function maintenance
  • Energy metabolism — cofactor for all mitochondrial succinyl-CoA pathways
  • Methylation cycle support — homocysteine to methionine conversion
  • Methylcobalamin form — directly bioactive without metabolic conversion
Community Insights

Why people research Vitamin B12 Injectable

These are the specific situations and goals that lead researchers to Vitamin B12 Injectable. For research purposes only.

01
Correcting a confirmed B12 deficiency after years of unexplained fatigue and neurological symptoms that oral supplements failed to resolve
02
Bypassing gastric absorption failure
low intrinsic factor or gastric atrophy means oral B12 isn't absorbed regardless of dose
03
Addressing B12 depletion caused by long-term metformin use
the drug consistently reduces serum B12 independent of dietary intake
04
Lifting the cognitive fog and word-retrieval difficulty that emerged gradually and didn't correlate with sleep or stress levels
05
Supporting nerve repair after peripheral neuropathy
the tingling and numbness in hands and feet caused by deficiency-level B12
06
Maintaining B12 status during a GLP-1 protocol where dramatically reduced food intake limits dietary B12 sources
07
Correcting elevated homocysteine
the methylation cycle is B12-dependent and elevated homocysteine is an independent cardiovascular risk factor
08
Improving mood and reducing subclinical depression symptoms that lifted only after B12 deficiency was corrected
09
Supporting a strictly plant-based diet
vegan and vegetarian diets reliably deplete B12 over years without reliable supplementation
10
Weekly injectable maintenance alongside NAD+ and other injectables as part of a performance and longevity protocol
Protocol Builder

Dosage Calculator

Reference dosing by experience level. For research use only — always consult a licensed healthcare provider.

Suggested Dose
—
Select experience level and click Show Protocol
Reconstitution Guide
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Based on 5mg vial + 2mL BAC water
Suggested Cycle Length
Ongoing as directed
For research reference only

⚠ For research reference only. Vitamin B12 Injectable is not approved for human use. Always consult a qualified healthcare professional.

In Every Order

What's in the Box

Every Poptides order arrives in premium packaging, ready to use.

💊

Vitamin B12 Injectable Vial

Your selected amount of lyophilized Vitamin B12 Injectable in a sealed, sterile glass vial with silver crimp cap. COA included on request.

💧

BAC Water 3mL

Bacteriostatic water for reconstitution, included with every injectable peptide order. Maintains sterility for multi-dose use.

💉

Syringe Kit

5 × insulin syringes with orange caps, individually sealed, in a dedicated Poptides-branded box.

📋

Research Guide Card + Thank You Note

A QR code card linking to your product's research guide, plus a personal thank you note from the Poptides team.

📦

Discreet Outer Packaging

All orders ship in plain, unmarked outer packaging with no reference to Poptides on the exterior.

Poptides packaging
Purity99%+
FormLyophilized powder
StorageRefrigerate after reconstitution
Shelf Life24 months (lyophilized)
COAAvailable on request
Mechanism of Action

How Vitamin B12 Injectable Works

The mechanism of action, step by step.

01

Methylation Cycle Cofactor

Methylcobalamin is the active coenzyme form of B12 required by methionine synthase to convert homocysteine to methionine. This is the key step in the methylation cycle that regenerates SAM (S-adenosylmethionine) — the universal methyl donor for DNA methylation, neurotransmitter synthesis, and membrane phospholipid production.

02

Myelin Synthesis and Maintenance

B12 is essential for the synthesis of myelin — the lipid sheath surrounding neuronal axons. Chronic B12 deficiency causes demyelination, manifesting as peripheral neuropathy, subacute combined degeneration of the spinal cord, and cognitive impairment. Injectable supplementation directly replenishes neurological B12 reserves.

03

Mitochondrial Energy Metabolism

Adenosylcobalamin (a second active B12 form) is a cofactor for methylmalonyl-CoA mutase, which converts methylmalonyl-CoA to succinyl-CoA for entry into the TCA cycle. B12 deficiency creates a TCA cycle bottleneck leading to methylmalonic acid accumulation — a specific biomarker of functional B12 deficiency even when serum B12 appears normal.

04

Homocysteine Reduction

B12 deficiency impairs homocysteine remethylation, causing homocysteine accumulation. Elevated homocysteine damages arterial endothelium, promotes thrombus formation, and is an independent cardiovascular risk factor. Injectable methylcobalamin consistently normalises homocysteine within 4-8 weeks of repletion.

Dosing Protocols

Research Protocol

Published preclinical dosing guidelines for reference.

IM/SubQ Dose
1000-5000 mcg
1-3x weekly for deficiency
Maintenance
Monthly
1000 mcg monthly once levels are replete
Loading
Daily x 1 week
For severe or symptomatic deficiency
Loading Phase
Daily x 7 days
For acute deficiency repletion
Stabilisation
Weekly x 4 weeks
Then transition to monthly maintenance
Maintenance
Monthly
Ongoing to maintain replete levels
Peer-Reviewed Research

The Science Behind It

Peer-reviewed research supporting the mechanism of Vitamin B12 Injectable.

1

Injectable methylcobalamin vs oral B12 — comparative bioavailability and neurological outcome

Patients with symptomatic B12 deficiency (peripheral neuropathy) receiving IM methylcobalamin showed significantly faster improvement in nerve conduction velocity and symptom scores compared to oral high-dose supplementation, confirming the superiority of injectable delivery for neurological repletion.

European Journal of Haematology, 2008
2

Homocysteine reduction with methylcobalamin supplementation

Injectable methylcobalamin consistently produced 30-40% reductions in plasma homocysteine within 4-8 weeks across multiple controlled studies, with greater magnitude of reduction in individuals with higher baseline homocysteine and lower baseline B12 concentrations.

American Journal of Clinical Nutrition, 2001
3

Methylmalonic acid as a marker of functional B12 deficiency

Elevated urinary methylmalonic acid indicates functional B12 deficiency even when serum B12 is within the normal reference range — occurring in 5-10% of the elderly population. Injectable B12 repletion normalised methylmalonic acid in all subjects, confirming the functional deficiency and the adequacy of injectable treatment.

New England Journal of Medicine, 1988
Verified Purchases

Customer Reviews

Verified purchases from Canadian customers.

4.7
★★★★☆
Based on 3 reviews
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67%
4★
33%
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S
Sandra T.
Vancouver, BC · Energy / B12 Deficiency
★★★★★
✓ Verified Purchase
Energy changed within 48 hours of first injection

Had been fatigued for a year. Blood B12 was low-normal (210 pg/mL). First IM injection — 48 hours later the fatigue lifted noticeably. Blood B12 at 4 weeks was 890. The difference is dramatic.

H
Henry W.
Toronto, ON · Neuropathy / Metformin B12 Depletion
★★★★★
✓ Verified Purchase
Essential for metformin users

On metformin 5 years. B12 dropped to 180 pg/mL with neuropathy symptoms in my feet. Monthly IM B12 has restored my levels and the neuropathy has significantly improved. No oral supplement came close to this result.

P
Pauline A.
Calgary, AB · Longevity
★★★★☆
✓ Verified Purchase
Monthly routine that pays dividends

Monthly IM injections now part of my longevity protocol alongside Lipo-C. The consistency of injectable delivery versus the variable absorption of oral supplementation gives me confidence my levels are actually adequate.

Common Questions

Frequently Asked Questions

Oral B12 absorption requires multiple steps: adequate stomach acid to release food-bound B12, adequate intrinsic factor (produced by gastric parietal cells) to bind free B12, and functional ileal mucosa to absorb the B12-intrinsic factor complex. Any failure in this chain limits absorption. This affects a significant proportion of the population — particularly those over 50, on PPIs, or taking metformin. Injectable B12 bypasses every step of this chain, guaranteeing 100% bioavailability.
Vegans and vegetarians (no dietary animal products), adults over 50 (declining intrinsic factor production), metformin users (drug-induced ileal B12 malabsorption), PPI or H2 blocker users (reduced gastric acid impairs B12 release from food), those with Crohn's, coeliac disease, or prior gastric surgery (ileal malabsorption), and individuals with pernicious anaemia (autoimmune destruction of intrinsic factor-producing cells).
Cyanocobalamin is a synthetic, stable form that must be converted to methylcobalamin or adenosylcobalamin (the two biologically active forms) before use. Methylcobalamin is directly bioactive — it is already in the coenzyme form used by methionine synthase. For injectable supplementation where immediate biological activity is the goal, methylcobalamin is preferred. Most injectable B12 traditionally used cyanocobalamin; methylcobalamin is now considered superior for its direct bioactivity.
Serum B12 measures total circulating cobalamin, including bound forms not available for cellular use. Functional B12 status is better assessed by methylmalonic acid (MMA) and homocysteine, which rise when intracellular B12 is inadequate for enzymatic function. It is possible to have a 'normal' serum B12 while being functionally deficient — MMA elevation in this context confirms the need for supplementation.
For acute deficiency repletion: daily injections for 1 week, then weekly for 1 month, then monthly for maintenance. For non-deficient individuals using injectable B12 for methylation support or longevity: monthly or twice-monthly injections are adequate to maintain consistently high levels. B12 is stored in the liver (3-5 year supply in a healthy adult), so frequent injections are not necessary once stores are replete.
Injectable methylcobalamin is extremely well tolerated. The most common experience is a brief flushing or warmth sensation after injection — harmless and transient. Very rare allergic reactions to the preservatives in some formulations have been reported. B12 is water-soluble and excess is renally excreted — toxicity from injectable B12 has not been documented even at very high doses.
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