Neurobion is the brand name of a product that contains vitamin B-1, B-6 and B-12. Such a combination is not permitted and had been banned in all advanced countries. In India, the government belatedly banned it. However to evade the ban, some manufacturers added one or two additional agents and have continued to market the same.
Such a combination is of no therapeutic value. Some patients get a perception of relief due to placebo effect. Such patients will get similar perception when distilled water is injected.