Our Team

Dr. Brendan M. Mccarthy

Dr. Brendan McCarthy founded Protea Medical Center in 2002. While he’s been the chief medical officer, Protea has grown and evolved into a dynamic medical center serving the Valley and Central Arizona.

A nationally recognized as an expert in hormone replacement therapy, Dr McCarthy s the only instructor in the nation who teaches BioHRT on live patients. Physicians travel to Arizona to take his course and integrate it into their own practices. Besides hormone replacement therapy, Dr. McCarthy has spoken nationally and locally before physicians on topics such as weight loss, infertility, nutritional therapy and more. Dr. McCarthy is viewed as been employed by the state medical board as an expert witness.

Often we look at the qualifications of a physician to help us choose a doctor. But if you ask any patient what makes a doctor stand out, he or she will tell you there is much more to a doctor than credentials and titles. A doctor needs to be compassionate, dynamic, and empathic. Dr. McCarthy has built his practice upon his dedication to each individual patient. He is passionate about both his work and educating patients on the meaning of their specific conditions. Individual patients through referral have built Protea Medical Center into the thriving practice it is today.

Through successful case after successful case, Protea has achieved its current position as a premier clinic dedicated to hormone balance, healthy metabolism, and the best quality of life.

Dr. McCarthy’s halmark is his unorthodox approach to mental/emotional wellness and its link to hormone balance in women and men. Through the use of blood work and clinical investigation, Dr. McCarthy gets to the bottom of possible causes for common conditions such as anxiety, PMS, depression, slow metabolism, weight gain, and insomnia.

Our Team


A co-owner of Protea, Celeste has her MA in English from the University of Hawaii. She has helped manage the practice with her husband, Dr McCarthy, since 2010. She also teaches yoga and writes her blog, whenever she finds time. She enjoys yoga, running, writing and hiking, as well as chasing around after three little kids and two dogs.

Dr. Elisabeth

Dr. Elisabeth Peffley

Dr. Peffley is a primary care physician. Her specialties include endocrine disorders, gastrointestinal conditions, aesthetics and anti-aging medicine, and lyme disease.

Dr. Peffley is a graduate of Southwest College of Naturopathic Medicine (SCNM), where she graduated with honors and spent over a year doing published medical research. Prior to attending SCNM, she attended a four year graduate program and received her license in  Acupuncture and Oriental Medicine.  Her undergraduate degree is from Colgate University where she graduated with a degree in mathematical economics with a double minor in French and psychology, while simultaneously completing her pre-med pre-requisites.

Dr. Peffley’s  strategy is to provide patients with exceptional healthcare that places an emphasis on a collaborative approach between doctor and patient to empower and educate her patients.  She believes in an integrated medical model, drawing on the best of what conventional and naturopathic medicine have to  offer in order to create a unique and individualized experience. She blends state of the art diagnostic testing with a wide variety of treatment modalities to provide patients with a revolutionized healthcare experience.

In her free time, Dr. Liz  (Peffley) enjoys spending time with her family. She also enjoys traveling, dancing, and a good movie .



My name is Kelsey Shannon. I was born in New Jersey, raised in Kansas City, Missouri, and moved to Arizona in September of 2016. I went to graduated from Oak Park Hugh School in Kansas City and have completed one year of community college.

I work at the front desk at Protea and I love what I do. I get to interact with hundreds of different people and learn a lot about medicine, which is a new experience for me. I also love creating relationships with patients.

Some things I like to do would be makeup artistry, singing and dancing. I’ve been performing for my whole life and I’ve been doing makeup for 3 years now. I love each one of those hobbies and they all make me who I am.

Our Team

Jilissa Guerra Back Office Manager

Jillissa Is a patient coordinator and phlebotomist at Protea Medical Center.In her free time she enjoys surfing, knitting and birdwatching. An avid collector of 19th century poetry Jillissa boasts a wide arrortment of Johann Wolfgang von Goethe’s collected works.



My name is Victoria. I graduated form Hamilton High and the Arizona school of massage therapy.

I am a receptionist here at Protea. I love doing my job because of the people I am able to help.

My hobbies and interest include watching scary movies and hanging out with my pets. I also enjoy nature, wildlife and landscape photography.


Darelyn Campbell Medical Assistant

My name is Darelyn Campbell I’m from Pima, Arizona. I am a registered medical assistant and phlebotomist at Protea Medical Center. I love being a part of this team where the possibilities are endless, and I can gain knowledge daily.

I am a scrub wearing, music loving, patient caring, soccer mom. Who loves spending time with my amazing friends and family!


Ashlyn Royce Patient Care Coordinator

My name is Ashlyn Royce. I am originally from Tucson, Arizona but grew up in California. Life happened to bring me back to Arizona and I currently live in chandler. I am attending asu for my BA in biology.

I have been working as a receptionist for Protea for about a year now. I love getting to know the patients that come in and bringing joy into their life. I love working with a team of doctors who change others lives.

My interests are country dancing, hiking, and swimming.


Nicole Warner Office Manager

My name is Nicole and I’m a front desk receptionist at Protea. I take incoming calls and faxes, schedule appointments, and keep things organized. I graduated from Dobson Highschool in 2012 and have attended MCC for three years.

My favorite things are my cat, books, and anything fantasy related. I also love the holidays and food.

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