John Marshall Mullins, MD

For the last 20 years, Dr. Mullins served as the Co-founder and President of the MESA Medical Group, the largest provider of Emergency and Hospitalist Physician Services in Kentucky. He specializes in recreating the manner in which medical services are delivered by instituting efficiency measures, programs based on accountability and results, and unwavering customer service.

With his expertise and knowledge, Dr. Mullins started Marshall Lifestyle Medicine, conceptualizing a new way of viewing health, aging, happiness and balance. Through the power of technology and concierge care, Dr. Mullins focuses on putting patient needs first and helping you to look, feel and perform your best.

Richard Miller, DO
Chief Medical Officer

Dr. Miller is a board-certified Internal Medicine physician. He received his undergraduate degree from The University of Texas at Austin and his medical degree from The University of North Texas Health Science Center – Texas College of Osteopathic Medicine. Dr. Miller completed his residency in Internal Medicine at LewisGale Hospital Montgomery in Blacksburg, Virginia, where he also served as a Hospitalist physician and faculty member for the residency program. He and his wife, Amanda, moved to Lexington in 2023 with their dog, Bear. Dr. Miller enjoys spending time with his family, golf, exercise and traveling. 

Chris Durham, MD

Director of Regenerative Medicine

Dr. Chris Durham, MD is a board-certified physician  specializing in preventive and personalized care. He focuses on identifying root causes of disease through advanced diagnostics, metabolic and cardiovascular risk assessment, hormone optimization, and lifestyle-based interventions. Dr. Durham partners closely with patients to create sustainable, data-driven plans that support long-term health, improved energy, and disease prevention, empowering individuals to take an active role in their health and longevity.

Steven Campbell, MD

Chief Innovation Officer

Dr. Steven Campbell’s interest in functional medicine was shaped by both personal experience and clinical insight. After years of refractory irritable bowel syndrome beginning in his teenage years—often worsened by traditional treatments—he became focused on root-cause, integrative care. This perspective was reinforced during the COVID-19 pandemic, when many critically ill patients had underlying metabolic disease that could have been addressed earlier. Since 2021, Dr. Campbell has practiced functional and integrative medicine both virtually and in person, helping patients optimize health, performance, and longevity.

Dr. Campbell is board certified in Internal Medicine, Pulmonary Medicine, and Critical Care Medicine, with advanced expertise in cardiopulmonary exercise testing and aerobic capacity optimization. He holds certifications from the Institute for Functional Medicine (IFM), Seeds Scientific and Performance Research (SSRP), and the Academy of Preventive and Innovative Medicine.

Danielle Bocook, MD

Director of Women's Midlife Care

Dr. Bocook is a board-certified Family Medicine Physician. She is a native of Hazard, KY. She received her undergraduate degree from Coastal Carolina University in Conway, S.C. She then started her previous career in Pharmaceutical Sales where she excelled for 10 years. She then realized she wanted to help patients in a more personal way and decided to go back to medical school. She received her medical degree from Saint James School of Medicine and completed her residency training through the University of Kentucky in Rural and Community Family Medicine at their Hazard Campus. Dr. Bocook is excited about her new role within the Marshall Medical Group as their Director of Women’s Midlife Care and looking forward to helping patients navigate through the obstacles of perimenopause and menopause. To prepare for this role, she has become a member of the Menopause Society. Dr. Bocook is focused on staying up to date on the newest studies and treatment recommendations to help her female patients maneuver through midlife’s natural transformations.