U.S. Department of Health and Human Services

Endocrinology Fellowship Faculty & Specialties

NIH faculty is dedicated to training endocrine fellows in the clinical and scientific basis of endocrine physiology and disease. Experts in various divisions work directly with fellows on patient care and in collaboration during rounds and conferences. A list of participating NIH Institutes and faculty is provided below.

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Diabetes, Endocrinology and Obesity Branch

This branch conducts clinical and basic research in the area of diabetes, insulin resistance, thyroid physiology and pathology, metabolism, and body weight regulation. Investigators study and treat patients with extreme insulin resistance, lipodystrophy, hypoglycemia, acromegaly and other disorders of carbohydrate and lipid metabolism. Studies of pancreatic islet biology, neuroendocrinology and immune modulation are conducted. Using the tools of the metabolic clinical research units, energy expenditure and thermoregulation are explored. Additionally, disorders of thyroid growth and function are studied providing clinical experiences in the treatment of thyroid nodules and cancer.


  • Dr. Rebecca Brown, Lasker Tenure Track Investigator, conducts research related to the pathophysiology and clinical therapeutics for rare disorders of extreme insulin resistance including lipodystrophy, mutations of the insulin receptor, and autoimmune conditions affecting insulin signaling.
  • Dr. Aaron Cypess, Acting Section Chief, Translational Physiology Section, whose current translational research projects in the lab focus on brown and white adipose tissue function, energy balance, clinical physiology, and imaging.
  • Dr. Phillip Gorden, Director Emeritus and Senior Investigator, is currently interested in clinical studies related to etiology, pathophysiology and therapy of insulin resistance including the treatment of lipodystrophic diabetes with leptin.
  • Dr. Ranganath Muniyappa, Program Director, studies of the metabolic and vascular actions of insulin and how these actions are impaired in insulin-resistant states such as obesity, diabetes, and cardiovascular disease
  • Dr. Lynnette K. Nieman, works on disorders of cortisol insufficiency and excess. Recent studies include an evaluation of the best imaging techniques to identify ectopic ACTH-producing tumors, and the utility of free cortisol and aldosterone measurement in the diagnosis of adrenal insufficiency.
  • Dr. Marc Reitman, Chief, Diabetes, Endocrinology and Obesity Branch, is interested in the mechanisms underlying energy homeostasis including metabolic rate and body temperature regulation, brown adipose tissue physiology, drug treatments for obesity, and BRS-3 (bombesin receptor subtype-3).
  • Dr. Kristina Rother, Section Chief, Section on Pediatric Diabetes, conducts clinical research with the goal to shed light on the underlying pathophysiologic mechanisms, contributing factors and to improve treatment for both type 1 and type 2 diabetes, with a focus on non-nutritive sweeteners.
  • Dr. Monica C. Skarulis, Chief, Clinical Endocrine Section, conducts multidisciplinary research in the area of obesity, weight loss and recidivism. She also conducts research in thyroid disease and neoplasia.
  • Dr. Simeon Taylor, Distinguished Investigator, Special Volunteer, conducts clinical and translational research related to pharmacotherapy of metabolic disease - with a special emphasis on genetic factors that predict an individual patient's response to specific drugs (i.e., Precision Medicine).

Metabolic Diseases Branch

This branch sees patients with disorders of calcium metabolism and metabolic bone disease, including sporadic and familial forms of primary hyperparathyroidism (e.g., Multiple Endocrine Neoplasia Type 1). Other patients include those with various forms of parathyroid hormone resistance and hypocalcemia.


  • Dr. Lee Weinstein, Chief, Signal Transduction Section, studies the pathogenesis and treatment of Albright hereditary osteodystrophy, pseudohypoparathyroidism, and related disorders. He also studies animal models to examine the regulation and role of G proteins in metabolism and hormone action.
  • Dr. William Simonds, Chief, Endocrine Signaling & Oncogenesis Section, studies clinical and basic scientific aspects of familial isolated hyperparathyroidism, parathyroid cancer, and the hyperparathyroidism-jaw tumor syndrome, as well as the function of the G protein beta5/R7-RGS/ R7BP signaling complex expressed in neurons and endocrine tissue.

National Institute of Child and Health Development (NICHD)

The investigators below seek to understand the genetic and molecular mechanisms leading to disorders that affect the adrenal cortex, with emphasis on those that are hereditary and associated with multiple tumors and abnormalities in other endocrine glands (i.e. the pituitary gland) and tissues of neuroectodermal origin (i.e. the melanocytes).


  • Dr. Constantine A. Stratakis, Scientific Director, and Chief, Section on Endocrinology and Genetics, investigates the clinical and genetic mechanisms leading to disorders affecting the pituitary gland and the adrenal cortex, with emphasis on those that are developmental, hereditary, and associated with hypoplasia or hyperplasia, multiple tumors, and abnormalities in other endocrine glands or systems. His molecular work focuses on the cyclic AMP signaling pathway, G protein coupled receptors, and their interactions with other signaling systems in a variety of models from human cells and tissues to animal models, mostly mice and zebra fish.
  • Dr. Karel Pacak, Chief, Section on Medical Neuroendocrinology, conducts research designed to elucidate the molecular genetic, biochemical and imaging bases for the clinical manifestations, laboratory findings, responses to treatment, and prognosis of patients harboring adrenal and extra-adrenal pheochromocytoma. 

Office of the Clinical Director

  • Dr. Jenny Blau, Staff Clinician, Co-Chief, Internal Medicine, Associate Program Director, Inter-Institute Endocrinology Training Program, NICHD studies glucose metabolism and the interaction with bone metabolism pathophysiology, with an emphasis on sodium-glucose co-transporters and their pharmacodynamics effects.
  • Dr. Andrew Demidowich, Staff Clinician – Co-Chief, Internal Medicine, Liaison, NICHD Medical Research Scholars, NICHD is interested in obesity and metabolic syndrome; specifically the inflammatory mechanisms which link obesity to its comorbid conditions, and how MC3R mutations predispose individuals to obesity. 

Reproductive Medicine

  • Dr. Alan H. DeCherney, Deputy Clinical Director for Academic Affairs and Program Director of the Reproductive Endocrinology and Infertility fellowship training program, conducts research regarding all aspects of infertility both male and female including In vitro- fertilization, fertility preservation and rare diseases associated with fertility impairment, basic gamete efficiency and, in the Epidemiology Branch, population based studies in regard to fertility.

National Institute of Dental and Craniofacial Research (NIDCR)

Craniofacial and Skeletal Diseases Branch


  • Dr. Michael Collins, Chief, Section on Skeletal Disorders and Mineral Homeostasis; Director, Career Development and Research Training, research focuses on understanding of bone and mineral metabolism through clinical and translational studies of human diseases, and animal models and in vitro systems.
  • Dr. Rachel Gafni, Pediatric Endocrinologist.
  • Dr. Allison Boyce, Pediatric Endocrinologist.
  • Dr. Mary Scott Ramnitz, Pediatric Endocrinologist.