can b12 injections cause skin rash Cutaneous lesions and vitamin deficiency: An often-forgotten link How to Spot and Treat

Many patients have found that over-the-counter supplements like B12 tablets, nasal sprays, and dissolvable capsules do not provide the same level of energy and mental clarity as their injections

The GLP-1R and GIPR pathways both converge on beta cell function through incretin signaling, and retatrutide provides a tool to study the amplified incretin response that occurs when both receptors are activated simultaneously

However, If blood levels are good (and you hadnt taken B12 before your bloodwork), you will likely not get extra benefit from extra B12 - meaning its not going to help boost your energy

Journal of Endocrinology and Metabolism, 3(12), 715