Yes, and this is common practice in the preclinical literature
A randomized, placebo-controlled Phase II study published in the peer-reviewed literature showed modest weight-loss effects at doses of 1 mg orally per day over 12 weeks, but the program did not advance to Phase III [1]
Vitamin B12 injections are generally safe, but some individuals may experience side effects, including: Pain or redness at the injection site Mild diarrhea Itching Nausea or vomiting Dizziness or headaches Hot flashes In rare cases, more serious reactions, such as allergic responses (rash, swelling, trouble breathing), can occur
Practical Formulation Considerations and Risk Mitigation While the chemical evidence does not support degradation concerns for this specific combination, reasonable formulation practices can further minimize theoretical risks: Reconstitute immediately before use when possible
The combination may produce better outcomes than either alone, though this has not yet been studied in controlled trials
With 2 mL, the same 0.1 mL is only a 5% loss