Father John's Medicine

Father John's Medicine is the brand name for a cod liver oil tonic, formerly manufactured and sold by Carleton & Hovey Co. (later rebranded Father John's Medicine Company) of Lowell, Massachusetts, and reputedly based on an 1855 formula preferred by Father John O'Brien, the tonic's namesake. A modern formulation of the same name, now containing dextromethorphan (DXM), is manufactured by the Oakhurst Company (Woolfoam Co.) to this day.

Composition
The formula has been provided as a mixture of cod liver oil, gum arabic, glycerin, with licorice and sugar water.