Methylcobalamin and vitamin B12 have slightly different effects, but both drugs can nourish nerves and can be used clinically for the treatment of limb numbness and sensory disorders. 1. Methylcobalamin is an endogenous vitamin B12 and has a better effect than vitamin B12 in nourishing nerves. Methylcobalamin exists in blood and bone marrow and has a good effect on improving neuronal conduction, so it is more effective than vitamin B12 in the treatment of neurological lesions.2. Vitamin B12 is a complex and cannot be directly used by the body after taking it. Methylcobalamin does not go through liver metabolism, so it works better than vitamin B12, but the price of methylcobalamin is also higher than vitamin B12.