Summary: Yes, vitamin B12 is a water-soluble vitamin, though uniquely it can be stored in the liver for several years despite being excreted through urine when consumed in excess
5-Amino-1MQ capsules contain a high-purity synthetic compound designed to inhibit nicotinamide N-methyltransferase (NNMT), playing a key role in metabolic regulation and energy homeostasis
"Hydroxocobalamin 1mg in 1ml solution for injection - Summary of Product Characteristics (SPC) - (eMC)"
Shields Compounding Pharmacy
There are also a number of health conditions that prevent patients from being able to absorb a sufficient amount of vitamin B12 both through their diet and through vitamin supplements, making injections the only method that ensures they are not deficient
No, you cant overdose, since B12 is water-soluble and any excess will be out in your urine in no time