Theriac is a medical concoction originally formulated by the Greeks in the 1st century AD and widely adopted in the ancient world as far away as Persia, China and India via the trading links of the Silk Route. It was an alexipharmic, or antidote, considered a panacea, for which it could serve as a synonym: in the 16th century, Adam Lonicer wrote that garlic was the rustic's theriac or Heal-All.

The ancient bestiaries included information—often fanciful—about dangerous beasts and their bites. When cane sugar was an exotic Eastern commodity, the English recommended the sugar-based treacle as an antidote against poison, originally applied as a salve. By extension, treacle could be applied to any healing property: in the Middle Ages, the treacle (i.e. healing) well at Binsey was a place of pilgrimage.

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