Hormones any members of a class of signaling molecules produced by glands in multicellular organisms that are transported by the circulatory system to target distant organs to regulate physiology and behaviour. Hormones have diverse chemical structures, mainly of 3 classes: eicosanoids, steroids, and amino acid/protein derivatives (amines, peptides, and proteins). 

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Neurotransmitters are the molecules used by the nervous system to transmit messages between neurons, or from neurons to muscles. The communication between two neurons happens in the synaptic cleft. Here, electrical signals are briefly converted into chemical ones through the release of neurotransmitters, causing a specific response in the receiving neuron. Most neurotransmitters are either small amine molecules, amino acids, or neuropeptides