Hormone
Hormones were chemicals secreted by s in certain parts of the body that triggered changes and responses in other parts or cells of the body. Hormones controlled and regulated activity of cells and organs such as metabolism, reproduction, growth, digestion, and mood. Neurotransmitters were a type of hormone. 

During pon farr, which was a Vulcan time of mating, cortical levels rose and fell, as the brain's regulatory system appeared to shut down when serotonin levels became unbalanced. () In female Vulcans, hormones and endorphins tended to rise to dangerous levels during the pon farr. ()

In response to Wesley Crusher's feelings of attractions for the allasomorph Salia, Geordi La Forge stated that "glands erupting with hormones" typically happened to those around his age. ()

Being jealous about his behavior towards Kes, Neelix called Tom Paris "one big hormone walking around the ship." ()

To describe the obvious tension between Tom Paris and B'Elanna Torres, The Doctor scanned the two with a medical tricorder and detected elevated hormonal levels. He advised them to take it easy or he'll have to declare a medical emergency. ()

To find a reason for their "out of control" behavior, Paris told Torres that the Srivani could have been messing around with their hormones. ()

See also 
 Estrogen
 Growth hormone
 Progesterone

External link 
 

de:Hormon
Biochemical compounds