Vitamin B12

Lyophilized powder

Vitamin B12 (cobalamin) is an essential nutrient used in energy metabolism, red blood cell formation and nerve function; injectable vials come as cyanocobalamin, methylcobalamin or hydroxocobalamin. It is a vitamin, not a peptide. Below: today's vial sizes, prices through our link and the vendor's COA details.

Size

$2.98/mg · In stock

Price

$29.75

List

$35.00

Buy 10 mg at Ion Peptide

Price shown uses code thepeptidecatalog at Ion Peptide's checkout (15% off list).

Volume pricing at Ion Peptide

4+ vials10% off$26.25/ea
6+ vials16% off$24.15/ea
10+ vials25% off$21.00/ea

Applied in Ion Peptide's cart; per-vial figures include our code.

Sold by Ion Peptide. The Peptide Catalog does not sell peptides; we earn a commission if you buy through this link, at no extra cost to you. For laboratory research use only, not for human or veterinary use. Not FDA-approved. Nothing on this page is medical or dosing advice.

Vitamin B12Ion Peptide

Third-party testedResearch use only

Certificate of AnalysisVendor-stated: Third-party tested · HPLC + MS · COA per productView

Vendor-stated testing: Third-party tested · HPLC + MS · COA per product
Listed on our vitamin b12 vendor comparison, ordered by our vendor rankings
Lyophilized powder · laboratory research use only

Research-context information only. Vitamin B12 is a vitamin, not a peptide. Protocols, doses, and reactions reported below come from published research and self-reported community sources. This article reports what has been documented, not what should be done. Consult a licensed physician for personal medical decisions.

Vial sizes listed by the vendor

Vitamin B12 Vial Sizes & Prices

Vitamin B12 vial sizes, prices and lots at Ion Peptide
Size	List	With our code	Per mg	Availability
10 mg	$35.00	$29.75	$2.98	In stock

Prices checked today, 5:15 AM CT on Ion Peptide's site, with code thepeptidecatalog applied. Vendor-stated testing: Third-party tested · HPLC + MS · COA per product. The lot certificate is on Ion Peptide's product page. Sizes not re-checked in the last 7 days are hidden. The vendor's checkout is final.

Test results

Vitamin B12 Certificate of Analysis

Ion Peptide posts the certificate on each product page (vendor-stated: Third-party tested · HPLC + MS · COA per product). Match the lot number on the vial to its certificate.

View the Vitamin B12 certificate on Ion Peptide's product page.

How to check one: how to verify a peptide COA.

Vitamin B12 Dosing in Clinical Research

Deficiency Correction / Energy Metabolism (Established Clinical Use)

Educational reference only. Individual responses vary. Consult healthcare provider before use.

Vial Size

10 mg injectable vial or dissolvable form

Reconstitution

Injectable forms ship as a ready solution; high-dose oral or sublingual is also effective

Dose

1000 mcg (1 mg) — the standard clinical unit

Timing

Any time of day

Frequency

Loading (daily or alternate-day) then maintenance (monthly IM, or daily oral)

Duration

Ongoing for absorption disorders (pernicious anemia, post-GI-surgery); until repleted otherwise

Protocol Notes

Essential water-soluble vitamin (cobalamin). The established deficiency protocol uses 1000 mcg via IM/SubQ injection (cyanocobalamin or hydroxocobalamin) — a loading phase then maintenance — or high-dose oral/sublingual (1000-2000 mcg/day), which can match injection even in pernicious anemia via roughly 1% passive absorption (PMID 9694707). Methylcobalamin is the active coenzyme form; cyanocobalamin converts readily in the body. Very low toxicity with no established upper limit. Backed by decades of human clinical data.

Why This Dosing Protocol

What dose is used? The established deficiency protocol centers on 1000 mcg (1 mg) — a loading phase followed by maintenance. Injectable cyanocobalamin or hydroxocobalamin and high-dose oral or sublingual forms are the common routes.

Why the form debate? Methylcobalamin is the active coenzyme form, but cyanocobalamin converts readily in the body and the evidence for clinical superiority of methylcobalamin is limited.

Full Dosing Guide Reconstitution Calculator Cycle Cost Calculator

How Vitamin B12 Works

Cobalamin — Essential Water-Soluble Vitamin / Enzymatic Cofactor (Extensive Human Clinical Evidence)

Target → Signal → Effect → Outcomes

Target

Two Cobalamin-Dependent Enzymes

Vitamin B12 (cobalamin) is an essential cofactor for two human enzymes: methionine synthase in the cytoplasm and methylmalonyl-CoA mutase in the mitochondria. Methylcobalamin and adenosylcobalamin are the two active coenzyme forms; cyanocobalamin and hydroxocobalamin are converted to them in the body.

Cellular Signal

Methylation & the Methionine Cycle

Through methionine synthase, B12 regenerates methionine from homocysteine, supplying S-adenosylmethionine (SAMe) for DNA, protein, and myelin methylation. When B12 is low, folate is trapped as methyltetrahydrofolate (the "methyl-folate trap"), stalling DNA synthesis — the basis of megaloblastic anemia.

Systemic Effect

Red Cells, Nerves, and DNA

Adequate B12 supports red blood cell production, DNA synthesis, and myelin maintenance. Deficiency causes megaloblastic anemia and a demyelinating neuropathy (subacute combined degeneration of the cord). These effects are established across decades of human clinical data.

What You Notice

Only If You Were Deficient

Correcting a deficiency reverses fatigue, paresthesia, glossitis, and cognitive fog over weeks. In people who are already replete, supplemental B12 produces no measurable benefit — it is a vitamin, not a stimulant.

What Makes This Peptide Different

Unlike most compounds on this site, B12 is an essential nutrient with FDA-approved injectable forms and decades of clinical evidence. The open questions are practical — which form (cyano / methyl / hydroxo) and which route — not whether it works. High-dose oral (1-2 mg/day) can match intramuscular dosing even in pernicious anemia through intrinsic-factor-independent passive absorption.

Technical specifications

Vitamin B12 chemical & analytical data

Form: Solution in a sealed vial
Presentation: 10 mg
Regulatory status: Vitamin (not a peptide); research-grade vials are not FDA-approved.

Vitamin B12 Reconstitution Calculator

Dilution math and unit conversions. Prefilled using a common vial size for this peptide.

Open calculator

Storage & Handling

Storage at a glance

Proper storage temperatures, shelf life, reconstitution best practices, and travel tips for lyophilized and reconstituted peptides.

Powder: Freezer

1+ year at -20°C

Reconstituted: Fridge

4 weeks max at 2-8°C

View Complete Storage Guide

Handling specifics

Educational overview on storage, labeling, and traceability considerations for lab environments. Consult primary literature and vendor documentation for specifics.

Powder storage (very stable)

Freezer (-20°C): 1+ year
Refrigerator (2-8°C): 1-3 months
Room temperature: 2-3 weeks (emergency only)

Reconstituted storage (fragile)

MUST refrigerate at 2-8°C
4-week maximum shelf life
NEVER freeze after reconstitution
Use bacteriostatic water for multi-dose

8 answers

Vitamin B12 FAQ: Buying, COA, Storage & Research

What is Vitamin B12?

Vitamin B12 (cobalamin) is an essential water-soluble vitamin the body cannot make on its own. It is a required cofactor for two enzymes — methionine synthase and methylmalonyl-CoA mutase — that drive methylation, red blood cell formation, DNA synthesis, and myelin maintenance. Common forms are cyanocobalamin, methylcobalamin, and hydroxocobalamin.

Does B12 give you energy?

Only if you are deficient. B12 is not a stimulant — it reverses the fatigue, anemia, and nerve symptoms of a deficiency, but produces no measurable energy boost in people who are already replete. The "B12 for energy" idea is a common misconception.

Methylcobalamin or cyanocobalamin — which is better?

Both work. Methylcobalamin is the active coenzyme form; cyanocobalamin is cheaper and more stable and converts readily in the body. Evidence for clinical superiority of methylcobalamin is limited. Hydroxocobalamin is longer-acting and is preferred for treating deficiency and in renal or cyanide-related cases.

Is injected or oral B12 more effective?

For most people, high-dose oral B12 (1000-2000 mcg/day) is as effective as intramuscular injection — even in pernicious anemia — because roughly 1% is absorbed passively without intrinsic factor. Injection is used for rapid repletion, severe neurologic deficiency, or when adherence is a concern.

Who is most likely to be B12 deficient?

Vegans and vegetarians, people with pernicious anemia, older adults with atrophic gastritis, long-term metformin users, long-term PPI or H2-blocker users, and anyone who has had gastric or ileal surgery. B12 deficiency is common and frequently underdiagnosed.

How long does reconstituted peptide last?

Once mixed with bacteriostatic water, peptides remain stable for up to 4 weeks when refrigerated at 2-8°C (36-46°F). Unopened powder can last 1+ year in the freezer. Get our complete Storage & Travel Guide.

Is this peptide legal to purchase?

Peptides sold "for research purposes only" are legal to purchase in the US, but are not FDA-approved for human use outside of specific medical applications. Always consult a healthcare provider before use.

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Vitamin B12 Research Articles

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Vitamin B12

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Vitamin B12 Certificate of Analysis