Is hemoglobin a hormone?

I'm really sorry it is not.

A new hormone called erythroferrone, which regulates the iron supply needed for red blood-cell production, has been discovered by researchers. Iron is an essential functional component of hemoglobin.

Hemoglobin is the iron-containing protein compound within red blood cells that carries oxygen throughout the body. It is made up of heme, which is the iron-containing portion, and globin chains, which are proteins. The globin protein consists of chains of amino acids, the "building blocks" of proteins.

when it is at an intermediate population density