|Molar mass||Molar mass::232.28 g/mol|
|CAS number||CAS number::73-31-4|
|Density and phase||Density:: 1.29 g/ml, Crystalline solid|
|Solubility in water||1.43e-01 g/l (?°C)|
|Melting point||Melting point::117°C|
|MSDS||Material safety data sheet|
|Main hazards||Slightly flammable|
| Except where noted otherwise, data are given for|
materials in their standard state (at 25 °C, 100 kPa)
Disclaimer and references
Melatonin is a hormone that helps control your sleep and wake cycles, which is sold as a food supplement to those experiencing sleep difficulty.
Melatonin has a melting point of 116-118°C. The boiling point of melatonin is not known though. The primary danger of melatonin is its slight flammability. Also, another danger of melatonin is inhaling the dust. If the dust is inhaled it can cause irritation of the throat and respiratory system. Although melatonin is often found in pill form, it is also crushed sometimes to take easier.
Synthesis / Occurrences
Melatonin is a hormone that is produced in the body by the pineal gland. The pineal gland is what regulates the production of melatonin. During the day melatonin is not produced in generally large quantities. The pineal gland regulates the production of melatonin by light. When it is dark outside the pineal gland then starts to produce melatonin. Your pineal gland is actually connected to your retina which shows the pineal gland the outside environment and conditions. This is one way that this gland knows when and when not to produce the melatonin. Melatonin is also formed in small amounts in the bone marrow, retina, bile, and also the gastrointestinal tract. 
While aging the production of melatonin in the body will gradually decrease. Melatonin is not stored in the body. Once it is synthesized it is released directly into the blood stream. Melatonin can be measured through urine and saliva. Saliva contains the majority of the melatonin though. 
Melatonin has a variety of uses. The most common uses for melatonin primarily have to do with people lacking sleep and/or problems getting to sleep. It is also used for quite a few other things as well. Many of these uses are fairly simple and are quite common. Other uses are for more serious conditions such as a variety of cancers and even Alzheimer's disease. These cancers include: breast cancer, brain cancer, lung cancer, and gastrointestinal cancer.  Melatonin is even used by some by as a sunscreen to protect against sunburn. Melatonin is actually a hormone that is found naturally in the human body. The melatonin that is found in pill form is made in laboratories and is synthetic. The main reason people buy melatonin is to help them sleep. It is extremely helpful in getting rid of jet lag and helping with sleep insomnia.
Most melatonin that is bought as supplements is prescribed by doctors because of sleeping issues. Although their are some people that just by the supplements from their local drug store without a doctor's permission. Melatonin is a primary substance for sleep. It is actually quite common for some people to have deficiencies in their naturally produced melatonin. Though it is less common in younger people it occurs, the majority of the time, in older people. The majority of the uses for melatonin are mostly limited to the aiding of sleep.
An intersting side effect of melatonin is that once you begin to not receive enough melatonin and not enough of it is manufactured by the pineal gland, your immune system becomes less competent and has to work harder in order to do its job. Deficiencies in melatonin also lead to heart problems as well. This occurs because melatonin is also known to help protect the heart. Some cancers also decrease the amount of naturally produced melatonin by as much as half. The pineal gland only produces melatonin when it is told that there is no light present. It receives this message from the brain because the pineal gland is fairly close to where your brain receives signals from the eyes.
Although it is not known to cause death or any extremely serious harm, it does have a few negative health effects including: daytime sleepiness, dizziness, head aches, abdominal discomfort, mild anxiety, irritability, confusion, and short lasting feelings of depression. Some of those side effects are actually much more common than others.