Sedative
From Memory Alpha, the free Star Trek reference.
A sedative is a drug used to calm down a patient or to induce sleep.
Sedatives are often administered with a hypospray in a dosage of usually not more than several ccs.
Aldebaran mud leeches can be used to treat insomnia as their secretions act as a natural sedative. (ENT: "Anomaly")
Captain Picard's Aunt Adele's recipe for a warm milk toddy was working perfectly as a natural sedative, as the heat activated amino acids in the lactose and it also tasted delicious. (TNG: "Schisms")
