Why are Non endocrine messengers not considered to be hormones?

Non-endocrine messengers are not considered hormones because they do not originate from endocrine glands and are not released into the bloodstream to exert systemic effects. Instead, they typically function locally, influencing nearby cells or tissues without the widespread distribution characteristic of hormones. Examples include neurotransmitters and local mediators, which act in a paracrine or autocrine manner. Thus, their mechanisms and modes of action differ significantly from those of traditional hormones.