I'm not a doctor but as far as I know melatonin helps you to adjust the body clock to a regular sleeping time, it means going to bed all the nights at the same time. Depends which kind of flights you have... but, usually, we always change time, that's why melatonin cannot be a solution.
Hmmm thanks for that explanation, that could explain why I've had some mixed results with melatonin.
After some lousy experiences (sleepless nights leaving me wrecked, despite having taken melatonin) I generally only use melatonin at home to re-adjust to my home time zone, or sometimes I use it down route if I have a longer lay over (2-3 days) if I need to recover from the cumulative effects after too many nights of insufficient sleep.
When struggling to sleep, especially when jetlagged, I find a couple of drops of Lavender Oil, or a spritz on the pillowcase is a great asset with no side effects.
Tried that as well, no result for me.
Fundamentally I think it's more important for the whole aviation industry (colleagues and regulators) to be more focused on
how to get sufficient rest, instead of tricks to stay awake.