Care That Considers the Full Clinical Picture

Chief Medical Officer

Dr. Zarfati connects mental health, hormonal health, medical weight management and longevity care through one coordinated clinical perspective.

Dr. Doreen Zarfati is Chief Medical Officer at Fountain Health NYC and a double board-certified psychiatrist. Her work spans mental health, longevity, metabolism and sexual health, with a particular interest in how biological and clinical factors can influence psychiatric symptoms and treatment response. At Fountain, Dr. Zarfati provides clinical oversight of Fountain’s care models, reviewing and approving them for clinical use and guiding how they are applied in patient care. Her work in IV ketamine focuses on neuroplasticity, emotional processing and the thoughtful integration of emerging treatments into structured clinical care. Her approach is individualized, collaborative and grounded in measurable response, with treatment evolving as the patient’s clinical picture changes.

Physician, Functional Medicine & Longevity

Dr. Teets is a board-certified family physician and Mount Sinai faculty member bringing integrative and functional-medicine training to Fountain’s longevity care, connecting prevention, chronic disease, metabolic health, and long-term risk within one clinical view.

Dr. Raymond Teets is a board-certified family physician with more than 20 years of experience practicing in New York. He earned his medical degree from Drexel University College of Medicine after studying philosophy at DePaul University and later completed a fellowship in Integrative Medicine at the University of Arizona. He also holds a faculty appointment at Mount Sinai and has experience across clinical practice, medical education and research. At Fountain Health, Dr. Teets focuses on preventive and longevity medicine, metabolic and hormonal health, and the management of chronic disease. His approach combines conventional medical evaluation with integrative medicine, considering medical and family history, laboratory findings, nutrition, lifestyle and other clinically relevant factors to determine what warrants treatment, closer evaluation or ongoing monitoring. Drawing on more than two decades of clinical experience, Dr. Teets brings a thoughtful, longitudinal perspective to care. He works with patients managing established medical conditions as well as those seeking to identify risk earlier, preserve function and take a more proactive approach to long-term health.

Physician, Internal Medicine & Hormonal Health

Dr. Klesaris brings more than two decades of internal-medicine experience to hormonal health, medically managed weight loss and age-management care.

Dr. Mary-Laura Klesaris is an internal-medicine physician with more than two decades of clinical experience and extensive postgraduate training in age-management medicine and bioidentical hormone replacement therapy. Her work has included hormonal health, medically managed weight loss, nutrition and individualized approaches to healthy aging. Earlier in her career, Dr. Klesaris served as Chief Medical Resident in the Mount Sinai–Cabrini program, where she helped supervise and educate interns and residents. Her clinical perspective combines conventional internal medicine with focused evaluation of hormonal, metabolic and age-related changes to help determine where treatment may be appropriate.

Physician, Personalized Oncology & Early Cancer Screening

Dr. Morris-Stiff brings personalized oncology and early cancer screening, with expertise in complex cancer care.

Dr. Gareth Morris-Stiff is a clinician-scientist and surgeon with extensive experience in hepatobiliary and pancreatic surgery, most recently at Cleveland Clinic. His career has included complex cancer care, development of novel cancer therapies, treatment of chemotherapy-related liver injury, metabolic liver disease and investigation of emerging clinical technologies. He trained in the United Kingdom, with additional clinical and academic experience across Europe, Asia, Africa and the United States. At Fountain, Dr. Morris-Stiff focuses on personalized oncology and early cancer screening, using medical and family history, individual risk and advanced diagnostics to determine where closer evaluation may be warranted. His approach considers metabolic health, nutrition, immune health and the microbiome alongside conventional oncology, with the goal of building a more individualized view of cancer risk and care.

Psychiatric Mental Health Nurse Practitioner

Oksana provides psychiatric evaluation and medication management for mood and sleep disorders, considering metabolic, hormonal and other medical contributors when clinically appropriate.

Oksana Fuller, PMHNP-BC, is a board-certified Psychiatric Mental Health Nurse Practitioner with training from New York University and Fairfield University. She specializes in mood and sleep disorders and the emotional challenges that can accompany major life transitions. Her approach combines psychiatric evaluation and medication management with attention to factors that can influence mental health, including sleep, nutrition, physical activity, stress physiology, metabolic health, hormonal changes and inflammation. Laboratory testing is incorporated when clinically appropriate and when it can help clarify the picture or guide treatment. Oksana works collaboratively with physicians, psychologists and other specialists when a patient's needs extend beyond psychiatry, helping keep mental-health treatment connected to the broader medical picture.

Clinical Psychologist

Dr. Pascal specializes in therapy for trauma, anxiety and depression, with expertise in DBT and ketamine integration.

Dr. Sara Pascal is a clinical psychologist with experience across inpatient, outpatient and emergency settings. She specializes in trauma, anxiety, depression and major life transitions, bringing a thoughtful, insight-oriented approach to psychological care. Her work combines psychodynamic therapy with evidence-based approaches including DBT, helping patients understand the patterns influencing how they think, feel and respond. At Fountain, she also works with patients receiving ketamine therapy, helping them process and integrate insights from treatment into lasting psychological and behavioral change. Dr. Pascal’s approach is grounded, practical and collaborative, with an emphasis on emotional regulation, self-understanding and greater agency in daily life.

Clinical Psychologist

Dr. Updegrove brings expertise in neuropsychology, trauma, EMDR and ketamine-assisted psychotherapy, with experience ranging from complex clinical cases to high-performing executives and athletes.

Dr. Erika Updegrove is a licensed clinical psychologist and Board Certified Behavior Analyst with training in clinical psychology and neuropsychology. Her experience spans outpatient mental health, neuropsychology, rehabilitation, behavioral health and multidisciplinary medical settings. Her clinical work includes trauma, neurological and psychiatric conditions, chronic pain, cognitive concerns, developmental differences and complex behavioral needs. She also has extensive experience working with high-performing individuals, including retired NFL players and C-suite executives. Dr. Updegrove incorporates evidence-based psychotherapy with trauma-focused approaches including EMDR and is trained in Gottman Method therapy and Ketamine-Assisted Psychotherapy (KAP). At Fountain, she draws on this broad clinical background to help patients understand patterns, develop practical strategies for change and integrate psychological treatment with their broader care when appropriate.

Registered Nurse

Megan brings emergency and cardiac critical-care experience from NewYork-Presbyterian/Columbia to the clinical monitoring and support of IV ketamine patients.

Megan Conway, RN, is a registered nurse with more than six years of experience in emergency and critical care, including work in the Cardiac Intensive Care Unit at NewYork-Presbyterian/Columbia. Her background has developed strong clinical assessment, critical-thinking and patient-monitoring skills in high-acuity settings. At Fountain Health, Megan supports patients receiving IV ketamine therapy, combining her critical-care experience with close clinical monitoring and a calm, patient-centered approach. She has a particular interest in mental health and in creating a treatment environment where patients feel safe, informed and supported.

Registered Nurse

Angie combines pediatric critical-care experience with expertise in IV therapies, supporting patients through medically supervised IV ketamine treatment.

Angie Truong, RN, is a registered nurse with a background in pediatric critical care and performance-focused medicine. She began her nursing career in the Pediatric ICU, building a strong foundation in clinical assessment, monitoring and early intervention. Her subsequent experience has included IV nutrient therapy, NAD+, hyperbaric oxygen therapy and other recovery and performance-focused treatments. At Fountain Health, Angie supports patients throughout IV ketamine treatment, combining attentive clinical monitoring with a particular interest in the connections between mental health, physical health, recovery and performance.

Executive Coach

Andrea works with executives, founders and elite performers on stress regulation, cognitive focus and sustained performance in high-pressure environments.

Andrea Wise is an executive performance coach and breathwork specialist with more than two decades of experience working with people operating in high-pressure environments. Her clients have included C-suite executives, professional athletes, hedge fund leaders, recording artists and founders—individuals for whom focus, resilience and sustained execution are critical. Andrea began her career in corporate leadership and training before moving into entrepreneurship, giving her direct experience with both organizational demands and individual performance. Her approach combines cognitive strategy, breathwork and nervous-system regulation to help clients manage stress, sharpen focus and perform more consistently under pressure.