The Breen Center for Optimal Health is a forward-thinking integrative health and wellness practice. Our mission is simple and uncompromising: to give you back your health and your life through education, empowerment, lifestyle optimization and evidence-based medicine.
01 · THE TRUTH
Tired, depleted, not yourself — and told your labs are “normal.” At the Breen Center, normal isn't the goal. Optimal is. Your journey begins by being truly seen.
Functional & integrative — we treat the system, not the symptom. Root-cause medicine that looks at all of you.
You aren't a number in our practice and we get to know you well. Unhurried visits with a physician who listens.
Modalities vetted against stringent standards for consistent, optimal outcomes — never trends, always evidence.
02 · THE PROVEN PROCESS
Comprehensive bloodwork and biomarker panels — the data foundation that looks far beyond a standard physical.
03 · SEE THE JOURNEY
From your first labs to a life lived fully — the Breen Center path, step by step.
04 · HORMONE OPTIMIZATION
Testosterone, thyroid and DHEA care for men; menopause, peri-menopause, PCOS, osteoporosis and thyroid care for women. Hormone therapy is prescribed only for a diagnosed condition, after an evaluation and laboratory testing, and only where clinically appropriate.
05 · Peak Performance PHYSICAL
A comprehensive screen — carotid ultrasound (CIMT), EKG, arterial-disease analysis, bone density, visceral fat, body composition, sleep study and metabolic rate — reviewed with you by Dr. Breen, in plain language.
06 · CARDIOVASCULAR & COGNITIVE
A personalised approach that looks past standard risk-factor scoring to the arterial wall itself — using imaging and laboratory markers to look for plaque and inflammation, and to inform a prevention plan. Individual results vary; no outcome is guaranteed.
A personalised protocol that looks at the metabolic, nutritional and lifestyle factors associated with cognitive decline. Individual results vary; no outcome is guaranteed.
07 · THE WELLNESS LAB
Built for preventive health, longevity, and a longer health span.
Red & near-infrared light, dosed for cellular recharge.
A red and near-infrared light bed. Photobiomodulation is studied for cellular energy, circulation and recovery; it is not a treatment for any specific condition and results vary.
High/low oxygen contrast floods tissues with oxygen-rich blood.
An exercise system that alternates higher and lower oxygen concentrations during training. It is a conditioning tool, not a treatment for any specific condition.
Electromagnetic pulses help cells recharge and self-regulate.
A pulsed electromagnetic field device used alongside nutrition and training. It is not a treatment for any specific condition and results vary.
08 · REGENERATIVE & LIFESTYLE
A range of services and programs, built around what each patient actually needs.
Regenerative options including GAINSWave acoustic-wave therapy and Platelet-Rich Plasma (PRP). These are not FDA-approved for this use and are offered at the physician’s discretion after evaluation.
One-on-one coaching, body-composition analysis, personalized nutrition plans, macronutrient optimization and supplement support.
Food-allergy testing, low-dose naltrexone, toxin burden testing, digestive health and genetic testing (MTHFR / APO-E) — root-cause medicine.
09 · THE PHYSICIAN
Dr. Sean Breen is a Doctor of Osteopathic Medicine (D.O.) licensed in California, practising family and adult medicine, with a long focus on Bioidentical Hormone Replacement Therapy (BHRT) for men and women. He has worked in hormone therapy for many years, including in the period before it was widely adopted, and treats patients navigating menopause and andropause. He is certified in Functional & Regenerative Medicine by the Metabolic Medical Institute, and holds medical licences in California (20A8273) and Florida (FL-20641).
What sets Dr. Breen apart isn't only his expertise — it's the way he practices. He takes the time to truly listen, to understand each patient as a whole person rather than a list of symptoms, and to build the kind of relationship that real, lasting health requires. Patients consistently describe feeling genuinely seen and heard, often for the first time in their medical journey.
A proud veteran, Dr. Breen served nearly a decade as a Naval medical officer and battalion surgeon, both stateside and overseas during his deployment in Iraq in support of U.S. Marines. He was awarded the Navy and Marine Corps Achievement Medal with Valor for his service.
Dr. Breen is happily married to the love of his life, Erin, and together they have been blessed with three wonderful children. They reside in Orange County, California.
10 · FEED THE SOUL
Food shifted the lens of my life from black and white to color.
That inner transformation sparked an insatiable curiosity about the relationship between what we eat and how we experience life — and I've spent the last decade sharing that understanding with everyone I can.
I serve as Lead Nutritionist at the Breen Center for Optimal Health, where I work alongside Medical Director Dr. Sean Breen. Working in true partnership with a physician gives me a privilege most nutritionists don't have: watching, in real time, how dietary and lifestyle interventions move the needle on extensive lab panels and diagnostics. I stay current on the latest nutrition research, attend medical conferences, and bring a working knowledge of functional medicine — from hormones to cardiovascular disease prevention — to every client I see.
Before the Breen Center, I worked with U.S. military personnel as Program Coordinator for Operation Live Well's Healthy Base Initiative aboard the Marine Corps Air Ground Combat Center, through the non-profit Share Our Strength.
"Health is not an end-goal or a number. It is the foundation required to live the life you deserve — not a destination, but a value you can use to navigate your life and choices."— Cat's guiding philosophy
THE SIGNATURE PROGRAM · FEEDTHESOUL™
A nutrition program curated for education, action, and guidance — designed to help you meet your health goals by radically shifting your relationship to food and balancing your mind, body, and soul. Over roughly eleven months, we work together with structure, loving support, and caring accountability.
BEGIN
Whether it's energy, hormones, heart health or clarity — the first step is a conversation. Our Irvine office is ready to answer your questions and help you begin.
IRVINE, CA · MON–THU 8:30A–5:00P · FRI 8:30A–4:00P
VISIT · IRVINE, CA
Tell us a little about yourself — the office will reach out to schedule your visit. Or call directly and speak with the team today.
