melatonin
melatonin — noun
1. a natural substance your body makes, mostly at night, to tell you when to feel s
a natural substance your body makes, mostly at night, to tell you when to feel sleepy and when to wake up; it is also produced artificially and sold as tablets or liquids to help with sleep problems such as jet lag or insomnia.
Hiro takes a melatonin tablet every night when traveling across time zones for work.
collocation: take a melatonin tablet / pill for jet lag
Antonia's doctor suggested melatonin to help her sleep after working night shifts at the hospital.
use for shift-work sleep disorder
Your body naturally produces melatonin when the sun goes down and the room becomes dark.
Beatrix bought some melatonin gummies to help her young son settle into a new bedtime routine.
- sleep hormone
everyday, non-technical term used in health articles and product descriptions
文法句型
no article when referring to the general substance
用法筆記
As a countable noun it usually refers to the supplement form ('a melatonin', 'two melatonins' — informal). In scientific writing it is always uncountable.