5 as in milligrams?! I’ve found 10mg is sometimes just enough, but 20-30mg is where I actually feel a noticeable difference
Just 1mg in liquid form is plenty for me, and that’s as someone who has had severe sleep onset difficulty for as long as I remember before I started using melatonin. I was told to hold the liquid under my tongue to absorb for a while before swallowing. I get it in 10mg/mL and it comes with a little oral syringe that you draw up 0.1mL with.
That’s…an extreme amount, as the other commenter said.