Meet Our Physicians

Discover Health is a union of Pediatric, Adult, and Naturopathic primary care physicians, formed with a mission to serve our patients with preventive and personalized care. Our focus is on disease prevention and the maintenance of wellness.


Oded Herbsman, M.D., FAAP

HerbsmanDr. Oded Herbsman is a board certified pediatrician with 20 years of experience in caring for children. His philosophy is to provide the care for his patients he expects his own children to receive. He combines evidence-based best practices with personalized, accessible and compassionate care.

With a focus on whole child and family-centered care, Dr. Herbsman’s practice provides the highest level of scientific knowledge combined with years of experience. He is a certified medical acupuncturist and Chinese herbal practitioner. The blend of Eastern and Western medicine, as well as his experience as a parent, give Dr. Herbsman a unique perspective in patient care.

After graduation from Duke University School of Medicine, Dr. Herbsman completed his pediatric residency at the University of California in San Francisco. In addition to his current roles as the Associate Chairman of Pediatrics and the Head of Pediatric Clinical Quality Assurance at California Pacific Medical Center, Dr. Herbsman has affiliations with Lucille Packard Children’s Hospital and the University of California San Francisco Medical Center.

Jon-Michael Castelli, M.D.

jm-castelliDr. JM Castelli is a pediatrician with over 10 years of experience in pediatric medicine in the Bay Area. He has been practicing in San Francisco for the past five years where he has earned a reputation as an expert clinician, diagnostician, and educator of colleagues, students, and families. His experience spans a broad range of pediatric medicine including neonatal and pediatric intensive care, as well as pediatric hospitalist medicine. Dr. Castelli’s approach to patient care is personal and collaborative, working with families to provide the best care for their children. He has long been lauded for his empathetic and attentive nature, a quality which has only grown since the birth of his two year old daughter.

Dr. Castelli graduated cum laude from Duke University and earned his medical doctorate at the Ohio State University College of Medicine, where he graduated with honors. He completed residency training at Lucile Packard Children’s Hospital at Stanford.

Dr. Castelli has been the medical director of the pediatric hospitalist program at the California Pacific Medical Center for the past three years, and has earned teaching awards for excellence in pediatric education from Dartmouth University.

In his free time, Dr. Castelli enjoys reading, writing, and practicing Pilates. But his favorite activities are that he and his wife, Holli, can laugh, play, and discover with their daughter, Cora.

internal medicine

Clifford Sewell, M.D.

SewellDr. Clifford Sewell is an internal medicine physician who founded his concierge primary care practice in San Francisco 1998. Most rewarding for him is the trusted bond he has with his patients.

Dr. Sewell was graduated from Duke University in 1988 with a B.S.E. electrical engineering, and then Georgetown University in 1989 with M.S. physiology. After medical school at Virgina Commonwealth University in 1994, he joined the Internal Medicine internship and residency program at California Pacific Medical Center, San Francisco.

Dr. Sewell was recruited by William Schwartz M.D. to serve as medical director of Samaritan House Medical Clinic, a free clinic for underserved patients in San Mateo, and continues today to volunteer his services in our community.

Radha Lewis, M.D.

LewisDr. Lewis is a family physician with 15 years of experience in family practice medicine and wellness. She has a particular expertise in Women’s Health Issues: Gynecology, Family Planning, Pregnancy, and Integrative Mood Support. She will be available to see all adults as well as teenage pediatric patients.

Dr. Lewis is known for her supportive and empathetic bedside manner and has an outstanding reputation for personalized health coaching for people who wish to maximize wellness or who are navigating difficult medical illnesses and decisions. She utilizes a broad skill set of traditional and complementary medicine depending on the interests of her patients.

Dr. Lewis grew up in Cape Cod, Massachusetts. She graduated from Harvard University with a major in Medical Ethics and attended Georgetown University School of Medicine. She completed her training at the UCSF/Sutter Medical Center in Santa Rosa, California, and a Fellowship in Women’s Health and Family Planning at the USC/LA County Women’s Hospital while completing a Master of Science in Clinical Research and Investigation from the University of Southern California.

In her free time, she continues her twenty years practice of yoga and meditation, enjoys making her own herbal medicines and hikes in the Redwoods.

integrative medicine

Thalia Farshchian, N.D.

T_FarschianDr. Thalia strives to educate and motivate her clients to become active participants in their own health and wellness. Specializing in women’s health, digestive conditions, hormone conditions and weight loss, she pieces together the constellation of symptoms to understand the core issue.

In order to create a successful plan, she believes a treatment should be tailored to an individual instead of forcing the individual to fit a treatment model. She is able to execute this by using a wide array of treatment options including herbal medicine, diet and nutritional supplements, lifestyle modification, intravenous therapy, bio-identical hormones and conventional medications when necessary.

Dr. Thalia shares her passion by contributing to local and national media outlets like The Honest Company blog, ABC news and Marina Times. Outside of the office, she keeps active traveling, salsa dancing, and sailing.

Dr. Thalia completed her degree in Naturopathic Medicine at the National College of Natural Medicine and her B.A. in Psychology from the University of California, Santa Barbara.

Christina Blankenburg, Wellness Coordinator

Tina brings a robust knowledge base ranging from general health and wellness, physical fitness via a professional background as a STOTT Pilates instructor, and last but not least, she is undergoing a Master’s program in holistic nutrition. The culmination of her skills and friendly demeanor create the perfect balance and understanding to support your journey on the Ideal Protein protocol.