5-HTP vs. Melatonin

5-HTP is transformed by your cells into a neurotransmitter called serotonin, which is then used by neurons to send chemical signals. Blood platelets also use serotonin whenever they form blood clots. Melatonin is a hormone that works with the "internal clock." Both 5-HTP and melatonin can be purchased as supplements to treat medical conditions, but check with a physician before taking these or any other supplements.

5-HTP

5-HTP is the abbreviation for 5-hydroxytryptophan, which is made from the essential amino acid tryptophan. You must get tryptophan from your diet, but once yours cells turn it into 5-HTP, 5-HTP can be converted into serotonin. The platelets in your blood release serotonin when they form blood clots; it reduces the diameter of the injured blood vessel, which lowers the loss of blood. The nerves in the digestive system, brain and spinal cord use serotonin to send chemical signals.

Serotonin and Depression

Serotonin helps to regulate emotions and mood. When released by the brain cells, it is recycled so it can be used again. Scientists have determined that people with depression often do not have the proper balance of serotonin. Either the serotonin has been recycled too soon, meaning it has been taken back by the nerve cell too quickly, or there is an abnormally low level to begin with. This is why a medication called a selective serotonin reuptake inhibitor, SSRI for short, is one type of treatment for depression. SSRIs interfere with the recycle of serotonin.

Melatonin

Melatonin, on the other hand, is a hormone excreted by the pineal gland, located in the brain. The gland releases melatonin into the bloodstream, influenced by levels of light. During the day, people have 2 to 10 pg/mL in circulation, while the level goes as high as 100 to 200 pg/mL at night, according to Kevin Barrows, MD in "Current Medical Diagnosis & Treatment." Thus, scientists have determined that melatonin regulates the "internal clock" of the body that says when it is time to wake up and when it is time to fall asleep.

The Uses of Melatonin

The University of Maryland Medical Center recommends checking with a physician before consuming melatonin. Some studies suggest it may help children with attention deficit hyperactivity disorder to fall asleep and help menopausal women with sleep problems as well. It appears that it can help prevent or mitigate jet lag, especially if you must travel by plane across five or more time zones, and can help those who work third shift to fall asleep. Scientists are also studying the association between melatonin and cancer, since people with prostate cancer and breast cancer often have low levels.