About
, holds double board certification in Endocrinology, Diabetes and Metabolism. She earned her undergraduate degree in Neurobiology and Behavior at Cornell University before completing her medical degree at Loyola University Stritch School of Medicine near Chicago. Her Internal Medicine residency at Indiana University took her through University Hospital, Methodist Hospital, Roudebush VA, and Wishard Hospital. She then completed a fellowship in Diabetes, Endocrinology and Metabolism, also at Indiana University, where she worked alongside leading experts in osteoporosis and bone disease. During fellowship, she published clinical research on the effects of metabolic disease and obesity on bone health.
Dr. Grethen spent more than 13 years at Ascension St. Vincent, serving on multiple medical committees focused on improving diabetes care. She practices evidence-based medicine exclusively and recommends only treatments with demonstrated safety and efficacy. Her clinical passions include diabetes, thyroid disease, osteoporosis, calcium disorders, adrenal and pituitary disease, and PCOS. She also served on a medical mission trip to remote villages in the Himalayas, providing care to underserved communities. A Chicago native, Dr. Grethen now calls Indiana home. She enjoys the outdoors, travel, and time with her husband and four children.
Education & Training
Undergraduate
Cornell University, B.S. Neurobiology and Behavior
Medical School
Loyola University Stritch School of Medicine
Residency
Internal Medicine, Indiana University, Indianapolis
Fellowship
Diabetes, Endocrinology & Metabolism, Indiana University
Additional Training
Published clinical research on bone effects of metabolic disease and obesity during fellowship
Certifications
Conditions Treated
Who is Dr. Grethen right for?
Dr. Grethen is a strong fit for adults managing complex endocrine conditions such as Type 1, Type 2, or gestational diabetes. Patients with thyroid disorders, osteoporosis, PCOS, adrenal disease, or pituitary conditions benefit from her broad specialty expertise. She works well with patients who want unhurried appointments and direct access to their physician. Those using insulin pumps or continuous glucose monitors will find her complimentary device download service especially useful. Patients who value evidence-based care and a thorough, communicative physician will feel at home in her practice.
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Frequently Asked Questions
Dr. Grethen treats a wide range of endocrine conditions. These include Type 1, Type 2, and gestational diabetes, hypothyroidism, hyperthyroidism, thyroid cancer, osteoporosis, hypercalcemia, hypocalcemia, parathyroid disease, adrenal insufficiency, Addison's disease, pituitary disease, PCOS, obesity, and abnormal testosterone levels. She also manages diabetes and thyroid disease during pregnancy.
Yes. Dr. Grethen holds double board certification in Endocrinology, Diabetes and Metabolism. She completed her fellowship training in Diabetes, Endocrinology and Metabolism at Indiana University.
Dr. Grethen earned her medical degree at Loyola University Stritch School of Medicine. She completed her Internal Medicine residency at Indiana University, rotating through several Indianapolis hospitals. She then finished a fellowship in Diabetes, Endocrinology and Metabolism, also at Indiana University.
Dr. Grethen practices evidence-based medicine exclusively. She recommends only medications, supplements, or services with demonstrated safety and effectiveness. She takes time to understand each patient's full medical history before determining a treatment plan, and she views thorough patient education as a core part of her role as a physician.
Yes. Dr. Grethen manages both insulin pumps and continuous glucose monitors as part of her practice. Members receive complimentary CGM and insulin pump downloads at their visits. She helps patients interpret device data to optimize their diabetes management.
Yes. Dr. Grethen manages both gestational diabetes and pre-existing diabetes during pregnancy. Impact Endocrinology offers a specialty short-term membership for diabetes in pregnancy, priced at $1,200, designed for patients who need focused endocrine support during that period.
Yes. Dr. Grethen treats thyroid disease during pregnancy as part of her clinical scope. The practice offers a dedicated short-term membership for thyroid disease in pregnancy at $950 for patients who need targeted care during this time.
Dr. Grethen manages prior authorizations on behalf of her patients. This service helps members avoid delays in getting access to the medications and treatments she prescribes.
During her fellowship at Indiana University, Dr. Grethen published clinical research examining the effects of metabolic disease and obesity on bone health. She trained alongside recognized experts in osteoporosis and bone disease during that time.
Yes. Dr. Grethen offers one-time consultations and second opinions for patients who do not wish to enroll in membership. These visits follow standard non-membership pricing.
Doctor profile last updated August 17, 2026