A molecule containing the antigen binding portion of an antibody specific for human glucocorticoid receptor phosphorylated at residue Ser211, Ser226 or Ser203 is obtained and a method of determining the presence of activated glucocorticoid receptors in cells from human glucocorticoid responsive tissue and a method of screening for a glucocorticoid agonist using the molecule, which is preferably an antibody, are provided in the present invention.