A 2019 hit song by the weekend called Blinding Lights goes
"I said, ooh, I'm blinded by the lights
No, I can't sleep until I feel your touch
I said, ooh, I'm drowning in the night"
The trouble is the same but the reasons are different. Here the reason is a heartbreak but there are several reasons for sleeplessness too. Being tossed in the ocean of life, nearing the age to retire or cultivating bad habits we just can't get our sleep right. So for you’re here too, you might need a bit of melatonin.
Melatonin is a hormone secreted by our body which manages the sleep-wake cycle. Exposure to white light, health problems or stress hampers the melatonin secretion thereby disrupting the sleep-wake cycle. 
Synthetic melatonin has been widely used as an effective sleep aid by several companies.
Nah. I don't want synthetic.
Not a synthetic fan? Well, we can get melatonin from plant sources too.
Yes, plants containing high amounts of melatonin are used wherein the melatonin is extracted from it. They are called phytomelatonin. 
Some of the plant sources of melatonin include
They contain a good amount of melatonin and were found to treat insomnia. Tart cherry juice is widely consumed and marketed as a sleep aid and for other health benefits as well.
Pistachio is a good source of melatonin and melatonin extracted from it can replace synthetic melatonin.