disclosed is the method of determining the effectiveness of an agent for relieving symptoms of the common cold , comprising the steps of a ) exposing a susceptible subject to vapors of a trigger substance reproducibly effective in producing within a period of 30 minutes a running nose lasting for at least 6 hours in the absence of treatment , b ) administering to said subject having been exposed to a trigger substance a predetermined quantity of the agent whose effectiveness is to be determined , c ) measuring the time required for the running nose to be abated , and d ) comparing the time required for the running nose to be abated with and without the administration of said agent . also disclosed are effective quantities of certain nutrient substances which can reproducibly relieve symptoms of the common cold produced in a susceptible subject by the administration of a trigger substance .