Most medical documents indicate you might experience any of these: Mild diarrhea and/or upset stomach Difficulty breathing or swallowing Weight loss or weight gain Nervousness or restlessness Nausea or vomiting Headaches or migraines Paresthesias (tingling sensations) Rhinitis (chronic sneezing or a congested, drippy nose) Skin reactions, such as rash, itching, swelling, blisters, or pain at the site of injection Light joint pain Lightheadedness or dizziness Chest pain or discomfort Low blood potassium levels Irregular heartbeat Chills, night sweats, fever, or hot flushes General feeling of sickness However, people often fail to recognize that many side effects of vitamin B12 injections are consistent with B12 deficiency itself
Based on a modified glucagon backbone with C18 fatty acid acylation supporting once-weekly dosing, it is currently being evaluated in Phase 3 clinical trials (SYNCHRONIZE program) and represents an area of active incretin receptor research
Medically reviewed by Alan Lucks | MD , Alan Lucks MDPC Private Practice - New York on December 13th, 2025
What patients commonly report The most consistent feedback we hear is about energy
