A potion flask is a bottle, usually made of glass and having a round body and narrow neck. It holds a drink or draft with reputed medicinal or poisonous effects. A flask can also be metal and is usually small enough to carry in a pocket.
Beyond the realm of science, potions such as love potions and sleeping potions are sometimes reputed to have magical properties. In mythology and literature, magical potions are made by magicians, sorcerers, dragons, fairies and witches. Love potions make the affected person fall in love or become infatuated, whereas sleeping potions cause a person to fall asleep.