Epinephrine (also known as adrenaline) is a neurotransmitter in the sense that, within the brain, it help neurons to communicate with one another.
However, because epinephrine is mainly produced by the adrenal glands and has functions peripherally (i.e., outside the brain), it can also be considered a hormone.
The adrenal medulla secretes epinephrine and norepinephrine.
These hormones increase alertness, pupilary dilation, piloerection, sweating, heartbeat, strength of heart contraction, rate of respiration, glycogenolysis, lipolysis, proteolysis.
Melatonin, cortisol, calcitonin are just hormones.