If you truly experienced "palpitations" after taking a 10mg or lower dosage of Melatonin, then I'd suggest you go see a Physician because there is something else wrong.
Perhaps you have an anterior motive in your statements but Melatonin is HIGHLY beneficial to anyone above the age of 45.
Your ridiculous comment about "hormone replacement" is a "straw man" statement and is misplaced within an article about Melatonin.
I am a user of Melatonin and a variety of supplements and
would have and do recommend Melatonin.