Methylcobalamin is a tissue-ready form of vitamin B12. It supports cardiovascular function, normal sleep cycles, red blood cell function, and nerve function.* Many vitamin B12 supplements contain cyanocobalamin as the active ingredient, which the liver must first ""detoxify"" and modify to form methylcobalamin – an active form of vitamin B12 that is essential for processes involved in cardiac function, sleep, red blood cell formation, and nerve function.* Thorne's Methylcobalamin provides vitamin B12 in its already biologically active and tissue-ready form.* Clinical evidence indicates that the body uses methylcobalamin more efficiently than cyanocobalamin.**