B12 has many functions in our body, so unfortunately a deficiency will give rise to a wide variety of symptoms, like brain fog, memory problems, cognitive impairment, insomnia, headaches, especially migraine, behavioural changes, learning problems, nominal aphasia, mood swings, irritability, depression, anxiety, hallucinations, delusions, psychosis, peripheral paraesthesia (pins and needles), numbness, neuropathic pains, poor balance, reduced vibration sense or proprioception (joint position sense), tinnitus, ataxia, taste impairment, sometimes myelopathy, fatigue, anaemia (either with larger red blood cells, or with normal size of the red blood cells when there is also iron deficiency), other reduction in blood cells, abdominal complaints, malabsorption, failure to thrive, weight loss, diarrhoea, hyperpigmentation, glossitis, (aphthous) stomatitis, infertility, urinary tract infections, joint and muscle pain, muscle weakness, spasticity, seizures, cardiomyopathy, urinary and/or faecal incontinence, postural hypotension/dizziness, erectile dysfunction, to name a few

Current Pharmaceutical Design , 2020 Cytoprotective Effects on the Gut: Orally administered BPC-157 has shown promise in protecting the mucosal lining of the stomach and intestines , though oral bioavailability is debated
What The FDA Category 1 vs Category 2 Status Means Today Under the FDAs interim bulk substances framework for 503A compounding pharmacies: Category 1: Bulk Drug Substances under evaluation with sufficient supporting safety information
Administer twice weekly or as directed by a veterinary surgeon