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Meet Our Care Team

A male doctor in a lab coat holds a stethoscope and crosses his arms over his chest.

Thousands of patients, over a decade of experience.

Consult with the Experts

Our care team has extensive experience in hormone restoration, sexual health treatment, and integrative wellness. They’re passionate about helping patients improve their lives and feel their best.

Defy Medical’s care team is led by Dr. Justin Saya, our medical director and lead practicing physician.

A photo of Defy Medical's medical director and lead practicing physician Dr. Justin Saya.

Medical Director and Lead Practicing Physician

Justin Saya, MD

Dr. Justin Saya graduated as class valedictorian from North Carolina State University with a dual bachelor’s degree in Biological Sciences and a bachelor’s degree in Economics. He received his medical degree from the University of North Carolina at Chapel Hill, School of Medicine, and subsequently performed his internship and residency training at the University of South Florida/Morton Plant Mease Family Medicine Residency Program.

In addition to his education and training, Dr. Saya is privileged to hold many certifications, honors, and memberships, including membership to the American Medical Association, the American Association of Family Practitioners, and the World Anti-Aging Academy of Medicine, among many others.

Dr. Saya offers therapy to both men and women who are looking to balance their hormone levels and improve their overall quality of life. His patients have reported benefits such as improved energy levels, restored libido, improved muscle tone and exercise tolerance when combined with an exercise routine, healthy/sustainable weight loss when positive eating and exercise habits are adapted, and much more.

He hears repeatedly from Defy patients that hormone replacement therapy is one of the best decisions they’ve ever made.

Caleb Calkins, MD

Dr. Calkins is focused on optimum health for his patients. He believes in a proactive approach to medicine that emphasizes maintaining an appropriate balance of nutrition, hormones, and fitness. He is dedicated to finding the root causes of his patient’s symptoms and the appropriate treatment regimens for complete wellness.

Dr. Calkins completed his bachelor’s degree in Public Relations with a minor in Nutritional Science at the University of Florida. While there, he was involved with research focused on the benefits of a ketogenic diet in improving epilepsy. He received his medical degree from St. Matthews University, and subsequently performed his internship and residency at Tulane University/East Jefferson General Hospital Family Medicine Residency Program in New Orleans, Louisiana. In addition, he received a master’s degree in Hospital Administration from Davenport University in Grand Rapids, Michigan.

Throughout his education and experience, Dr. Calkins has seen the benefit of using multiple modalities to improve patient outcomes.

A photo of Defy Medical's Dr. Calkins.
A photo of Defy Medical's Beth Bray, APRN.

Beth Bray, APRN

Beth Bray, APRN, comes to Defy with over two decades of medical experience. She started her career after graduating from Prairie State College and became a Registered Nurse where she worked in hospital settings for orthopedics and oncology.

In 2015, she completed her graduate degree from Northern Illinois University and began working in Primary Care and Integrative Holistic Care.

Beth cites the importance of forming a partnership with her patients to help them work towards optimal health goals and allowing them to live their absolute best lives. Additionally, Beth feels that Defy is on the cutting edge of hormone replacement therapy and integrative wellness.

Beth recently made the trek from icy Illinois to sunny Florida and became a member of the Defy Medical team in February of 2021. Since moving to Florida, she’s developed a passion for gardening and just about anything else the Florida sunshine has to offer. Beth is also an avid reader and is usually zipping through an Octavia Butler Sci-Fi novel in her free time.

Jill Dillenburg, RN

Jill Dillenburg, RN, has practiced as a board-certified registered nurse for the past 10 years.

She has specialized in the areas of hormone replacement therapy and cardiology. Since 2014, Jill has practiced with Defy as both a provider and the medical manager to Defy’s team of medical assistants.

Jill graduated from Galen College of Nursing in 2010 with a Registered Nurse degree. She initially practiced in cardiology assisting with clinic patients, nuclear stress testing, and pacemaker implantation before starting with Defy. Jill is enthusiastic about helping individuals rediscover themselves in mind and body for optimal health and happiness.

Her approach to hormone replacement therapy is a holistic one, addressing both hormone levels and lifestyle factors to improve one’s daily quality of life. Due to her many years of practicing as an IV nutritional specialist, she is proficient in evaluating for vitamin and mineral deficiencies that contribute to fatigue, weight issues, and cognitive function. Jill finds patient education via telemedicine both rewarding and gratifying. She empowers individuals to be their own best advocate through a deep understanding and knowledge of their health.

A photo of Defy Medical's Jill Dillenburg, RN.
A photo of Defy Medical's Mellisa Faulk, PA-C.

Melissa Faulk, PA-C

Melissa Faulk, PA-C, graduated Summa Cum Laude from South University in 2003 with a Bachelor of Physician Assistant Studies. Melissa is a NCCPA (National Commission on Certification of Physician Assistants) board-certified physician assistant with nearly 20 years of clinical experience in the fields of military medicine, orthopedic trauma, cardiology, and hormone replacement. She has specialized in men’s health for more than 10 years.

Melissa has a passion for U.S. military service members and veterans due to her personal service in the Army. She served as the lead PA for Army’s Center of Aviation SERE-C course, graduated from the Army Flight Surgeon course in 2009, and served several years in Afghanistan caring for U.S. soldiers.

Melissa approaches patient care from a functional perspective, seeking to uncover and address the root cause of imbalance. She also understands that optimized health requires an integration of physical, mental, and psychological well-being.

Melissa is diligent in partnering with patients to formulate individualized plans to meet their health and wellness goals, whether that be increased energy, vitality, or changes in body composition.

Mike Linkous, PA-C

Mike Linkous, PA, completed his bachelor’s degree in Adult Fitness/Exercise Science at Marshall University in West Virginia. He received his Physician Assistant degree from The College of West Virginia in Beckley, West Virginia in 2000. Since then he has worked in Sports Orthopedics, Family Medicine, Integrative Hormone Medicine, and Pain Management.

As a member of the Defy Medical provider team, Mike takes an integrative approach to treating patients. In addition to his extensive medical training and practice, Mike also brings unique personal perspective to his patient consultations as he has been on TRT for more than 15 years.

A photo of Defy Medical's Mike Linkous, PA-C.
A photo of Defy Medical's Janel Mayer, MSN, APRN.

Janel Mayer, MSN, APRN, FNP-C

Janel Mayer, MSN, APRN, FNP-C obtained her bachelor’s degree in Nursing from Penn College in 2004 and gained valuable experience caring for critically ill patients at some of the finest facilities on the east coast. In 2014, she completed her graduate degree as a family nurse practitioner at Chamberlain College of Nursing. She went on to obtain certifications in the fields of nutrition, weight loss, hormone balancing, and aesthetics through Empire Medical.

As a nurse practitioner with more than 15 years healthcare experience, Janel’s passion for improving overall health and vitality through diet/lifestyle modification and hormone balancing is evident in the meticulous care she provides to her patients. She loves helping patients look and feel their best through comprehensive treatment plans based on their individual needs and desires.

Ben Walker, APRN, DC

Ben Walker, APRN, DC received his Doctor of Chiropractic degree in 1989 and has been a nurse practitioner since 2014.

His interest in the integrative approach to healthcare inspired him to explore and understand the many facets of optimizing personal health. When working with his patients, Ben applies his years of medical knowledge and practice to understand the physical, nutritional, and emotional aspects of a patient’s lifestyle.

Ben himself has been on bio-identical hormone replacement therapy for the past 4 years and has had the opportunity to get acquainted with the many benefits of a thorough and comprehensive approach to using HRT as a means to restore a patient’s overall well-being. His in-depth and personal experience with integrative healthcare allows him to truly understand the various needs of his patients.

A photo of Defy Medical's Ben Walker, APRN, DC.

What Patients are Saying

See More Testimonials

“...Dr. Saya and team have been a godsend for me...”

“Dr. Saya and team have been a godsend for me. Other doctors have brushed me off, saying my labs were in ‘normal’ range, but never listened to the symptoms I was suffering from. Working with Defy has been the best decision I’ve ever made and I’ll continue to recommend them to others.”


“...Dr. Saya is knowledgeable and thorough in his work...”

“Friendly staff. Prompt service. Dr. Saya is knowledgeable and thorough in his work. Definitely recommend.”


“...I want to thank Dr. Calkins from the bottom of my heart...”

“No doctor in my town wanted to treat me because I was only 25, despite having diagnosis, imaging and bloodwork indicating I needed the help. I want to thank Dr. Calkins from the bottom of my heart. The past few months have been so liberating for me and I finally feel in control of my life. Also, for the first time in my life, I can truly say I’m happy. I’m not just going through the motions to get through the day anymore.”


“...actually helpful in achieving sustainable long-term health stability...”

“I am able to trust that the providers at Defy will continue to offer patient-driven, cost-effective, hormone-based healthcare solutions that are actually helpful in achieving sustainable long-term health stability.”


“...We have been seeing Dr. Saya, and now Jill, for several years now...”

“We have been seeing Dr. Saya, and now Jill, for several years now. I even switched my thyroid care to them as well. I no longer have the hot flashes (YES!), and my moods are even, no extreme mood swings. Thank goodness!”


“...I wish I would've started with them sooner...”

Been with Defy for about a year now and I have to say they’ve been phenomenal. Every staff member I’ve talked to or emailed has been very nice and prompt. Dr. Saya has been fantastic. This team has consistently given me peace of mind and treated me very well. Every penny has been well spent. I wish I would’ve started with them sooner.

–L. Pod

“...every interaction has been outstanding...”

“Been with Defy for over two years. Have consulted with Dr. Saya, Ben and Melissa. Every interaction has been outstanding, including those with customer service. I have not had one memorable, negative experience. Any and all concerns are dealt with promptly and always professionally and with a smile (determined by tone).”


“...I felt like I had an actual say in the process...”

“My consultation was with a PA (Michael Linkous)…. He went into great detail about the blood work; it was very informative. He did a very good and thorough job, and I am grateful for his knowledge and feedback. In addition to the thoroughness, I was also grateful that I as a patient had a say in what treatment I would undergo. Nothing was pushed, I never felt pressured, and I felt like I had an actual say in the process.”