Meet The Team


Larry Leibowitz, MD

Larry Leibowitz, MD, board-certified in family medicine, has been in practice since 1999. With the launch of his concierge practice, Matrix Personalized Medicine, in June 2017, he will offer highly individualized care by addressing the unique needs and preferences of each of his patients.

Recently recognized as a 2017 Castle Connolly Top Doc in Fairfield County, Dr. Leibowitz serves as the Director of Health for the town of Redding. Prior to launching Matrix, he was the Medical Site Director of Stamford Health Medical Group in New Canaan. He continues to serve as a Clinical Assistant Professor of Medicine at New York Medical College, a position he has held since 2009.

In 2015, he completed a two year Integrative Medicine fellowship at the University of Arizona, acknowledged as the leading integrative medical education program in the world. Dr. Leibowitz earned his medical degree from Jefferson Medical College at Thomas Jefferson University in PA and completed his residency at Abington Memorial Hospital in PA. He earned a Bachelor of Arts degree in Psychology from Emory University in 1987.

Dr. Leibowitz discusses how concierge medicine benefits both patients and physicians.

Dr. Leibowitz’s credentials

  • Board Certified, American Board of Family Medicine, Recertified 2005 – present
  • Medical Director, Stamford Health Medical Group, 2011 – 2017
  • Clinical Assistant Professor of Medicine, New York Medical College, Valhalla, NY, 2009 – present
  • Fellowship in Integrative Medicine, University of Arizona, 2013 – 2015
  • Residency, Abington Memorial Hospital, Abington, PA, 1996 – 1999
  • MD, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA, 1996
  • Post-BS Premedical Track, University of Connecticut, 1992
  • BA, Psychology, Emory University, 1987


  • Castle Connolly, Top Doc Award, Fairfield County, 2017
  • Vitals Most Compassionate Doctor Award

Vanessa Lucas

Vanessa Lucas is a Medical Assistant who has lived in New Canaan for over 20 years with her husband and daughter.  She is a graduate from The University of London in Laboratory Science specializing in Bacteriology and Immunology. She trained at the National Heart and Chest Hospital in Kensington London, and graduated to managing a Medical Laboratory in Harley Street, London.  In 2000, having a desire to return to the medical field and follow her passion working directly with patients, Vanessa returned to school and graduated from the Medical Assistant program at Norwalk Community College.  For the past 15 years Vanessa has worked and subsequently been the Nursing Supervisor at a large Obstetrics and Gynecology office in Stamford.  We are proud to bring Vanessa to Matrix Personalized Medicine.

Alison Perry

Alison Perry graduated from the University of Rhode Island with a degree in communications and worked for many years in the cosmetic and pharmaceutical industries before becoming a stay-at-home mom.  As her children grew, she became interested in a career in health care and pursued her Medical Assistant certification.  Patients will find her to be dedicated, friendly and very engaging, and we are proud to have her on the team.  Alison lives with her husband and three children in Wilton, Connecticut.

Cathy Katin-Grazzini

Plant-Based Nutritional Coach & Culinary Instructor

A seasoned plant-based nutritional coach and chef, Cathy works with patients to help prevent, treat and often reverse their chronic diseases.

Certified in Plant-Based Nutrition from the T. Colin Campbell Center for Nutrition Studies at Cornell, a graduate of Rouxbe Cooking School’s Professional Plant-Based Program, Cathy is also a Licensed Instructor for the Physicians Committee for Responsible Medicine’s Food for Life Programs.  She has a B.A. from the University of Chicago, attended graduate school at Harvard University and achieved her M.A. from Johns Hopkins University.  Cathy lives with her husband Giordano in Ridgefield.

Cathy is the owner of Cathy’s Kitchen Prescription LLC. Her original recipes, cooking videos, and nutritional blogs can be found at

Nancy Byrne

Licensed Acupuncturist

Nancy Byrne is a Licensed Acupuncturist, Chinese Herbalist, and certified practitioner of Yamuna Body Rolling, Yamuna Breathwork, Yamuna Face Ball, and Yamuna Foot Fitness. She earned her Master’s degree in Traditional Oriental Medicine (MSTOM) from Pacific College, and is nationally accredited by NCCAOM. Nancy has additional training in yoga therapy and pilates, and experience in personal training and physical therapy.