New Era Comb J contains ferr phos, kali mur and nat mur. Ferr phos is traditionally used in the early stage of colds and feverish symptoms, kali mur is the tissue salt most often linked with thick mucus and congestion, and nat mur is commonly used for streaming discharge, sneezing and irritated mucous membranes.
That makes New Era Comb J easy to understand. It is a product for nose, throat and chest symptoms where things may start runny, then turn blocked or chesty. Biotin is included as well, and biotin contributes to the maintenance of normal mucous membranes, which fits the product's respiratory focus.
The ingredient mix is useful because it covers more than one stage of a cold. Nat mur suits the watery phase, kali mur is often chosen as congestion thickens, and ferr phos is there when heat, soreness or a feverish edge are part of the picture.