In general, excess B12 is flushed out by your body and is unlikely to cause harm
10.1074/jbc.M111.253039 Summary Keywords stable gastric pentadecapeptide BPC 157, fistula, bleeding disorder, concept practical applicability, wound healing Citation Seiwerth S, Milavic M, Vukojevic J, Gojkovic S, Krezic I, Vuletic LB, Pavlov KH, Petrovic A, Sikiric S, Vranes H, Prtoric A, Zizek H, Durasin T, Dobric I, Staresinic M, Strbe S, Knezevic M, Sola M, Kokot A, Sever M, Lovric E, Skrtic A, Blagaic AB and Sikiric P (2021) Stable Gastric Pentadecapeptide BPC 157 and Wound Healing
This study is an initial foray into the question
They work best for clients who are already following a nutrition plan and staying active, using the injections to support energy, liver function, and metabolism
Banned at all times by WADA