Meet Our Team

Luis Barrera Luis Barrera is a medical professional and healthcare operator with a career that bridges clinical practice, healthcare administration, and modern wellness medicine.

He began his medical training at the Instituto Tecnológico y de Estudios Superiores de Monterrey (ITESM), completing medical school through the ITESM School of Medicine (EMIS). His seven-year education included internship and clinical rotations, with elective majors in General Surgery and Gastroenterology, providing a strong foundation in procedural medicine and patient care. He graduated from ITESM as Medical Surgeon.

Following medical school, Luis worked in pain management, where he gained extensive experience in interventional procedures while developing a deep understanding of the U.S. healthcare system, insurance structures, and practice operations. Over time, healthcare administration became as central to his career as clinical medicine, shaping his ability to operate, scale, and optimize medical practices without losing focus on patient outcomes.

In 2014, Luis relocated to Tucson to help establish a pain management practice, where he led key operational functions while continuing hands-on clinical work, including procedural care, C-arm operation, and mild sedation monitoring. He later joined Desert Sky Spine and Pain, where he founded his first medical management company and supported multiple practices, balancing administrative leadership with clinical oversight.

This experience led to his entry into wellness medicine and hormone replacement therapy, including participation in early patient consultations and clinic development. In 2022, Luis joined Low T Clinic to expand operations and help build the foundation of a successful, concierge-style hormone replacement therapy practice. Through this work, he developed deep expertise in hormone optimization, menopause care, medical weight loss, and peptide therapies.

Recognizing the need for a more accessible, patient-centered model, Luis founded Sonoran Weight Loss. The clinic was built around concierge medicine principles, offering unrestricted one-on-one consultations, continuous provider access, and high-quality care at accessible pricing. His vision is to establish Sonoran Weight Loss as the premier medical-spa clinic in Arizona while partnering with like-minded clinicians to expand access to evidence-based wellness care.

Marissa Nuñez, MSN, FNP-C Marissa Nuñez, MSN, FNP-C is a board-certified Family Nurse Practitioner with a strong passion for hormone optimization and peptide therapy. She is dedicated to helping patients restore balance, improve vitality, and feel their best through evidence-based, individualized care.

With a comprehensive approach to health and wellness, Marissa focuses on identifying root causes and creating personalized treatment plans that support long-term outcomes—not just short-term fixes. She prioritizes patient education, safety, and collaboration, empowering individuals to make informed decisions about their health.

Marissa is committed to ongoing education in functional and regenerative medicine and stays current with advances in hormone replacement therapy and peptide protocols. Her practice philosophy centers on thoughtful listening, clinical excellence, and helping patients achieve sustainable wellness at every stage of life.