Melatonin as a Sleep Aid

Carbs can become protein, seriously, Out of the 20 amino acids you need to survive, the body manufactures 11 of them from a combination of a glucose (usually broken down into different variations during glycolysis,) hydrogen, and oxygen. It's not really rocket science.

As for melatonin, like I said, studies have been done, and they show no difference in effect between low and high doses. Melatonin supplementation is for retraining your circadian rhythm. It will change when your body produces melatonin, if you take it at a different time than is normal. Also, melatonin production is based on light and darkness, which is why shift workers can often have trouble producing enough melatonin to sleep properly, as their light and dark signals get mixed up.

As for it's antioxidant properties, I haven't seen any studies that show more is better there, either. There are a lot of powerful antioxidants that lose effectiveness and can even be toxic at too high a dose. I'm not saying the dosages for melatonin are dangerous, just unnecessary. Why spend more money for a higher dose capsule, when you can save money with a lower dose that is just as effective? More is not always better.