In clinical trials, the most common adverse effects were gastrointestinal, including nausea, vomiting, diarrhea, and constipation
Dissection of the anti-inflammatory effect of the core and C-terminal (KPV) alpha-melanocyte-stimulating hormone peptides
This includes confirmed low serum vitamin B12 levels, pernicious anaemia, malabsorption states such as coeliac disease, inflammatory bowel disease, or post-gastric or bariatric surgery, unexplained anaemia, neuropathy or neurological symptoms consistent with vitamin B12 deficiency, a long-term vegan diet with symptoms or low levels, or failure of oral vitamin B12 supplementation
This means very small amounts may have strong biological effects