退黑激素 tuì hēi jī sù

DEFINITIONS

  1. melatonin

CHARACTERS

退 tuì
HSK 5
step back, retreat, withdraw
黑 hēi
HSK 2
black; dark; evil, sinister
激 jī
HSK 4
arouse, excite, incite; quickly
素 sù
HSK 5
white (silk); plain; vegetarian; formerly; normally