Progesterone and estrogen appear to have a positive effect on lung function and reduce the symptoms of asthma, according to a report published by University of Pittsburgh Graduate School of Public Health (GSPH) researchers in the March issue of Annals of Allergy, Asthma & Immunology, the scientific journal of the American College of Allergy, Asthma and Immunology. “We found that women’s lung function and asthma symptoms improve when estrogen and progesterone levels are raised, both naturally during certain times in the menstrual cycle and with the administration of oral contraceptives or hormone replacement therapy,” said one of the study’s lead researchers.