Dr. Michel K. Stephan is a board-certified physician and the trusted Medical Director at First Rate Infusion & Wellness Care. He brings years of experience in clinical medicine, patient safety, and wellness innovation—ensuring every service provided meets the highest standards of care and compliance.

Passionate about holistic and patient-centered medicine, Dr. Stephan works closely with the First Rate team to blend science and compassion in every treatment—from IV vitamin therapy and weight management to mental health and Spravato® programs. His calm leadership and commitment to quality care help create an environment where patients feel supported and confident in their wellness journey.

Outside of medicine, Dr. Stephan is a devoted husband and father who enjoys spending quality time with his family. He’s an avid golfer and skier, always finding balance between his dedication to healthcare and his love for the outdoors.

Teria Mullin isn’t your average healthcare provider — she’s the visionary behind First Rate Infusion & Wellness, Mesquite’s #1 wellness clinic and the only ketamine therapy provider in the city.

Her journey began long before opening her clinic. In college, a professor once told her she should quit because she had just given birth to her first child. Instead of stopping, Teria used that moment as fuel to push forward. Years later, she earned two of the most respected credentials in healthcare: Certified Registered Nurse Anesthetist (CRNA) and Family Nurse Practitioner (FNP-C).

Today, her mission is simple: to help people live well, think clearly, and feel their best through personalized services. Teria leads with compassion, science, and a warm personal touch — creating a clinic experience that’s supportive, uplifting, and truly first-rate.

When she’s not in the clinic, Teria enjoys traveling, dancing, and spending time with her family — the people who inspire her every day.

Mwandu Chisanga is a dedicated Psychiatric Mental Health Nurse Practitioner (PMHNP) with a unique background that combines the art of communication with the science of compassionate care. Before pursuing her nursing career, Mwandu earned her first degree in Journalism, which strengthened her ability to listen deeply, connect with people’s stories, and communicate with empathy—skills she now brings to every patient encounter.

At First Rate Infusion & Wellness Care, Mwandu provides thoughtful, evidence-based mental health support through psychiatric evaluations, medication management, and integrative wellness approaches. Her calm, understanding presence helps patients feel heard, valued, and supported as they work toward mental and emotional balance.

Mwandu’s philosophy centers on treating the whole person—not just the diagnosis—while promoting resilience, growth, and wellness. Outside of her professional role, she enjoys writing, exploring new experiences, and spending time with family and friends.

Carolina Montemayor is a dedicated Medical Assistant whose warm personality and attention to detail help make every visit at First Rate Infusion & Wellness Care a comfortable and positive experience. With a strong passion for patient care and wellness, Carolina supports both the clinical team and clients through every step of their journey — from check-in to treatment follow-up.

She takes pride in creating a welcoming environment, assisting with IV vitamin therapy, injections, and wellness services with professionalism and care. Known for her kindness and reliability, Carolina ensures that each patient feels valued, informed, and supported throughout their visit.

Outside of work, she enjoys spending time with family, staying active, and continuing to learn more about health and wellness to better serve her community.