Yes
In the brain, dopamine functions as a neurotransmitter, activating dopamine receptors. Dopamine is also a neurohormone released by the hypothalamus. Its main function as a hormone is to inhibit the release of prolactin from the anterior lobe of the pituitary. By Dr Ananya Mandal, MD. Dopamine is a neurotransmitter. It is a chemical messenger that helps in the transmission of signals in the brain and other vital areas. Dopamine is found in humans as well as animals, including both vertebrates and invertebrates. Dopamine production. Dopamine is produced in several areas of the brain, including the substantia nigra and the ventral tegmental area. It is a neurohormone that is released by the hypothalamus. Dopamine is an organic chemical of the catecholamine and phenethylamine families that plays several important roles in the human brain and body, as well as elsewhere in biology. Its name derives from its chemical structure: it is an amine formed by removing a carboxyl group from a molecule of L-DOPA. Dopamine itself is used as precursor in the synthesis of the neurotransmitter norepinephrine and the hormone epinephrine. Dopamine is converted into norepinephrine by the enzyme dopamine β-hydroxylase (DBH), with O 2 and L-ascorbic acid as cofactors. Dopamine is a neurotransmitter that helps control the brain 's reward and pleasure centers. Dopamine also helps regulate movement and emotional responses, and it enables us not only to see rewards, but to take action to move toward them.  By: Steve R. Dopamine has been dubbed the “happy” hormone, and rightly so. It is the chemical in your brain that has the most drastic effect on your emotions, view of pleasure and pain, and even how your body moves and how you behave in your daily life. Most types of reward increase the level of dopamine in the brain, and a variety of addictive drugs increase dopamine neuronal activity. Other brain dopamine systems are involved in motor control and in controlling the release of various hormones. Dopamine itself is used as precursor in the synthesis of the neurotransmitter norepinephrine and the hormone epinephrine. Dopamine is converted into norepinephrine by the enzyme dopamine β-hydroxylase (DBH), with O 2 and L-ascorbic acid as cofactors. We observed strikingly low serum concentrations of growth hormone (GH) and prolactin (PRL) during a therapeutic, standardized, isovolumetric, partial exchange transfusion (blood sampling every 20 min for 6 h) in two polycythemic neonates requiring intensive therapy, including continuous dopamine infusion. Dopamine inhibits growth hormone and prolactin secretion in the human newborn. De Zegher F, Van Den Berghe G, Devlieger H, Eggermont E, Veldhuis JD. Most recent answer: Dopamine is both a hormone and a neurotransmitter. It acts as a hormone in the blood and as a neurotransmitter in the central nervous system. -www.dictionary.com-. Yes, it is a hormone which, by definition, is released by endocrine cells directly into the bloodstream, to have an effect elsewhere in the body. Dopamine is release by the hypothalamus to inhibit the release of prolactin in the anterior lobe of the pituitary gland. It is also released by the adrenal medulla to constrict blood vessels as part of the 'fight or flight' reaction. Dr Sarah Brewer, author of The Human Body (Quercus) For example, dopamine plays a big role in starting movement, and the destruction of dopamine neurons in an area of the brain called the substantia nigra is what produces the symptoms of Parkinson’s disease. Dopamine also plays an important role as a hormone, inhibiting prolactin to stop the release of breast milk. Back in the mesolimbic pathway, dopamine can play a role in psychosis, and many antipsychotics for treatment of schizophrenia target dopamine. 
http://www.vitamins-supplements.org/hormones/dopamine.php http://www.news-medical.net/health/What-is-Dopamine.aspx https://en.wikipedia.org/wiki/Dopamine https://www.psychologytoday.com/basics/dopamine http://www.naturalscoop.com/how-to-increase-your-happy-hormone-dopamine/ https://en.wikipedia.org/wiki/Dopamine http://www.ncbi.nlm.nih.gov/pubmed/8284103 http://www.answers.com/Q/Is_dopamine_a_hormone http://www.slate.com/articles/health_and_science/science/2013/07/what_is_dopamine_love_lust_sex_addiction_gambling_motivation_reward.html
is dopamine a hormone