The vast, vast majority (many quintillions of them) would be completely inert: random strings of amino acids in some incoherent order that your body simply metabolizes back into its constituent parts and repurposes into something thats actually useful
In this case, the B12 shots have started to heal the damaged neurons myelin sheath, but the neural network in which the healed neuron is in, is in a super sensitive state (with extra receptors), so the patient may feel pain or other unpleasant sensations
It is indicated in the treatment of vitamin B 12 deficiency due to a lack of absorption: Biermer's disease, removal of the stomach or part of the intestine, Imerslund's disease, and in this case it will have to be administered intramuscularly
For instance, AOD 9604 peptide may be used to observe targeted fat loss patterns
It is a single-use product