Fibromyalgia is a disease that is diagnosed by exclusion, meaning that doctors only suspect the disease when all other possibilities are ruled out. This disease can affect up to 30 percent of the population and is more likely in women . You can start suspecting that you may have fibromyalgia if you start to notice that you are constantly fatigued, have unexplained pain and notice you are more irritable than usual . The standard treatment is a bombardment of anti-depressants, anti-psychotics, and pain-killers but although they come with FDA approval, they do not mean they are without side effects . Patients suffering from this disease often consider supplements for fibromyalgia. These can range from simple 5-HTP for better sleep, taking SAMe for your depression or even magnesium for healthy brains and bones. Another supplement for fibromyalgia to consider goes by the name "melatonin, " but the question is, does melatonin treat fibromyalgia pain?
Melatonin for Pain
In medicine, we have already known that melatonin was a compound that was very important for regulating the cardiovascular system, helping in digestion and even influencing our sleep cycles but it was only in the last decade that melatonin was thought to have another use: for treating chronic pain syndromes. 
There is some controversy when it comes to melatonin deficiencies and fibromyalgia. Serum melatonin levels were found to be nearly identical when comparing fibromyalgic patients to healthy ones when awake yet it was also found that urine melatonin levels were much lower in patients with fibromyalgia compared to healthy subjects .
One research determined that melatonin levels were on average 30 percent lower than levels seen in healthy patients during their sleep .
Melatonin was further investigated to determine how effective it was at relieving fibromyalgic pain. In this experiment, 101 fibromyalgic patients were given either melatonin, fluoxetine or a combination of these two agents. Fluoxetine is a selective serotonin reuptake inhibitor (SSRI), a standard medication that can be used to treat depressive symptoms . At the conclusion of this investigation, it was determined that the SSRI was effective at treating depression and improving the mood of patients, but when combined with melatonin, patients noticed a decrease in the number of tender points which caused pain. As you can see, melatonin treats fibromyalgia pain. 
Why Does This Work on Insomnia?
When determining why melatonin works as fibromyalgia pain relief, all you have to do is look at the physiology behind what is going on in your body to understand why it works. When patients have chronic pain syndromes, there is often an underlying disturbance of their circadian rhythm. When you are in pain, it is hard to fall asleep and stay asleep throughout the night, which is where a valuable supplement for fibromyalgia can make its mark. Melatonin not only regulates your circadian rhythm, so you feel more rested after sleep, it also is involved in releasing endorphins. Endorphins are responsible for controlling the majority of our behavioral urges and are a natural "reward mechanism" for us to do things that our body wants. Drinking, eating, sexual urges and even pain responses are all directly controlled by endorphins .
The reason that melatonin has a close relationship with pain is that both of these follow a circadian rhythm. Just think about the last time you had a stomach ache or even a simple headache. After you fell asleep, your body no longer felt the same painful stimuli, and you were able to "block it out" until the next morning .
Studies have shown that as little as 3mg of melatonin per day can be effective in not only restoring sleep patterns in patients suffering from fibromyalgia but also tremendously improve their tolerance of pain . The most important thing to be mindful of is when taking this medication. If a patient waits too long to take their medication, melatonin will be ineffective at improving their sleep disturbances. Studies find that if you take melatonin after your body has naturally secreted dim-light melatonin, the effects of supplemental melatonin are lost .
It should be obvious at this point that when considering supplements for fibromyalgia, melatonin treats fibromyalgia pain. Melatonin possesses sedative, hypnotic, analgesic and anti-inflammatory properties that make this an attractive alternative therapy. In 9 out of 10 trials, it was shown to reduce anxiety significantly, and 3 of 5 studies demonstrated that melatonin could be a useful option to manage pain compared to stronger opioids. Melatonin does not have the same addictive properties that are seen in more potent pain-killers. In most cases, the pain level that is experienced by patients suffering from fibromyalgia does not come close to illnesses that require these strong painkillers, so it is better for patients to avoid stronger medications when possible.