The best needle for B12 injection into fat tissue would be within the 4-5 mm size range, combined with a gauge of 30G or higher

Berkeley Heights, NJ 07922 Revised December 2023 PIN350-WES/6 NDC 0143-9621-01 1 mL Vial Cyanocobalamin Injection, USP Rx only 1,000 mcg/mL For IM or SC use ONLY Protect from light Contains Benzyl Alcohol NDC 0143-9621-25 Rx only Cyanocobalamin Injection, USP 1,000 mcg/mL For Intramuscular or Subcutaneous use ONLY Contains Benzyl Alcohol as a Preservative 25 x 1 mL Vials NDC 0143-9620-01 10 mL Multiple Dose Vial Cyanocobalamin Injection, USP Rx only 10,000 mcg per 10 mL (1,000 mcg/mL) For Intramuscular or Subcutaneous use ONLY Contains Benzyl Alcohol as a Preservative NDC 0143-9620-10 Rx only Cyanocobalamin Injection, USP 10,000 mcg per 10 mL (1,000 mcg/mL) For Intramuscular or Subcutaneous use ONLY Contains Benzyl Alcohol as a Preservative 10 x 10 mL Multiple Dose Vials NDC 0143-9619-01 30 mL Multiple Dose Vial Cyanocobalamin Injection, USP Rx only 30,000 mcg per 30 mL (1,000 mcg/mL) For Intramuscular or Subcutaneous use ONLY Contains Benzyl Alcohol as a Preservative NDC 0143-9619-10 Rx only Cyanocobalamin Injection, USP 30,000 mcg per 30 mL (1,000 mcg/mL) For Intramuscular or Subcutaneous use ONLY Contains Benzyl Alcohol as a Preservative 10 x 30 mL Multiple Dose Vials NDC 0143-9619-01 Rx only Cyanocobalamin Injection, USP 30,000 mcg per 30 mL (1,000 mcg/mL) For Intramuscular or Subcutaneous use ONLY Contains Benzyl Alcohol as a Preservative 1 x 30 mL Multiple Dose Vials

Those who may have trouble losing weight through traditional methods alone
Instead of three standard meals, eat five to six smaller meals spaced 2 to 3 hours apart
B12 Form Choice Should Match the Reason for Treatment Methylcobalamin may be preferred when nerve-related symptoms, methylation issues, or persistent fatigue remain part of the clinical picture