Both the National Institutes of Health (NIH) and the Institute of Medicine have not established an upper limit for B12 intake, even when doses exceed the daily recommended amounts by thousands of micrograms (source: National Institutes of Health)
For 1 mg this equals 0.1 ml or 10 units on the syringe scale

Bacteriostatic water is compatible with and recommended for the following categories of research peptides available from Peptides Lab UK: GLP-1 receptor agonists Semaglutide, Tirzepatide, and related GLP-1 analogue preparations Amylin analogues Cagrilintide and related amylin receptor agonist preparations Dual and triple peptide combinations CagriSema, and other soluble multi-peptide blends BPC-157, TB-500, and most tissue repair peptide preparations Cerebrolysin and neuropeptide preparations with neutral-pH solubility VIP (Vasoactive Intestinal Peptide) and other hydrophilic neuropeptides Most peptides where the product datasheet specifies sterile water or bacteriostatic water as the reconstitution solvent Bacteriostatic Water UK Specifications Product Details Composition: Sterile water for injection + 0.9% w/v benzyl alcohol Grade: Sterile, laboratory / research grade pH: 57.0 (typically 5.06.5) Form: Sterile aqueous solution in sealed vial with resealable rubber stopper Multi-use: Yes benzyl alcohol preservative maintains sterility across repeated needle access Storage: Store at room temperature (1530C)

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