Giving a vitamin B12 supplement to a healthy dog who is eating a nutritionally complete and balanced dog food is usually not necessary, but its also unlikely to be dangerous
In a human study, over 91% of participants reported reduced knee pain after BPC-157 injections
Vitamin B12 injections are generally safe, but some people may experience side effects, such as pain, redness, or swelling at the injection site, mild headaches, dizziness, nausea, or itching
The HCG injections for fertility can be given either under the skin subcutaneously or into the buttocks intramuscularly depending on the doctors choice
We can all agree that B6 is a possible cause of peripheral neuropathy but based on the limited information here, everything points to the neuropathy being from a B12 deficiency, not a B6 overdose