Jan 06, · Adults In adults, the average hemoglobin level is slightly higher for men than it is for women. It’s measured in grams per deciliter (g/dL) of blood. Older adults also tend to have lower hemoglobin Author: Rachel Nall, MSN, CRNA. Jul 23, · The normal adult hemoglobin (abbreviated Hgb or Hb) molecule contains two alpha-globulin chains and two beta-globulin chains. In fetuses and infants, beta chains are not common and the hemoglobin molecule is made up .