Look into the research behind melatonin use. I’m not a doctor and certainly long term use of diphenhydramine is associated with neurological problems in old age, but I’m not sure melatonin should be used as a simple hypnotic as you are suggesting. It’s natural but so is testosterone. Hormones may not be good to tinker with. I say that as a long time user of melatonin. At the very least you may want to stick with lower dosages- nothing over 1mg which is about as low as is easy to find.
Kids versions don't come in anything higher than 1mg and one can make it a half-dose quite easily. It's really more of a last resort thing, and definitely not for every night's bedtime. How last resort? Maybe once or twice a month. Now that my kids are a bit older and bedtime rituals are established it's even more rare.
I realize that some parents reach for it every night and this is not something I'm suggesting.
