Our Team


McCall McPherson, PA-C, Founder

You can find more about my academic accomplishments below, but I thought I'd start with the more interesting stuff. You can get a more in-depth understanding of who I am and how I practice on my website at www.mccallmcpherson.com.

I ended up in this fascinating niche of medicine for a few reasons. The most profound was my own case of hypothyroidism, that I simply could not get managed and left me almost non-functional for more than 6 months. Repeatedly I went to my doctor begging for help, asking that he look deeper than my TSH which was “normal,” even though I was 27 years old and literally going to bed at 3:30 in the afternoon, not to mention I had almost every last symptom of hypothyroidism. It wasn’t until I learned that thyroid disorders are much more complex to diagnose and treat than a simple TSH and Levothyroxine, that I got my life back. Years later for obvious reasons, my passion runs deep for solving people's thyroid problem; it's my jam and my life’s calling.
Professionally speaking, I'm a licensed and nationally certified Physician Assistant with prescriptive authority. I graduated Magna Cum Laude with a Bachelor's Degree from Texas State University in Psychology in San Marcos, Texas. I then packed up my bags and moved to New York City to earn a Master’s Degree as well as an additional Bachelor’s degree in Physician Assistant Studies at Mercy and began my certification from the prestigious Institute for Functional Medicine in 2015.

I love and live in Austin, with my two daughters. In my free time I enjoy running, live music, yoga, hiking and camping.

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Sara Klopp, PA-C

Hi!  My name is Sara Klopp, and I am a nationally board-certified Physician Assistant, providing healing, medical care to the Austin community since 2004.  I graduated with a Master’s of Health Sciences, Physician Assistant Studies, from the University of Oklahoma. I moved to Austin shortly thereafter, as I was drawn to the friendly atmosphere that reminded me of home, all of the outdoor beauty, and the vibrant live music scene.  I have felt so fortunate to help others in my career, working in many different areas of medicine including primary care, gastroenterology, and internal medicine, where I managed many people with acute and chronic issues, including thyroid disorders.  I joined McCall at Modern Thyroid Clinic in 2017 and my work has been such a joy!  It’s so rewarding – for me and my clients – to see the quality-of-life improvements through positive lifestyle changes and proper medications, while digging deep to address the root cause of illness.  I tell my friends, family, and patients, this was the way I was meant to practice medicine - to truly be your guiding partner in optimal health & wellness.


Melody Volz, FNP-C

Melody graduated in 2008 with a Bachelor of Science in Nursing from the University of Texas at Austin. She went on to get a Master of Science in Nursing, also from the University of Texas, and become a certified Family Nurse Practitioner in 2014. After getting her bachelor’s degree, Melody worked for 5 years at Dell Seton Medical Center and has spent the last 5 years working in primary care with a focus on thyroid disorders and hormone imbalances.

Melody’s personal thyroid journey began as an 18-year-old freshman in college when she started having overwhelming fatigue, brain fog, and sleep disruption.  After being told she was “just a tired college student”, she dug deeper into her own health and was finally diagnosed with hypothyroidism and Hashimoto’s.  Since then, she has spent the last 17 years developing her passion for helping others that are suffering like she was and sharing with them what she’s learned about thyroid and hormone support, not only as a clinician, but also as a patient herself.

Melody’s philosophy is simple - no two patients are alike. While thyroid and adrenal hormones impact every single cell in the body and cause a myriad of symptoms if unbalanced, often patients have their own individual set of symptoms unique to them. When a person is unwell, their whole life can unravel and that affects more than just a set of labs or their symptoms, it is often the underlying core of their entire wellbeing. Melody is committed to treating her patients as individuals, not just a set of one-size-fits-all lab results and works with each one to achieve optimal hormone levels that leads to a life of overall wellness and balance.

Melody lives in Austin with her husband and 2 young daughters and enjoys being outside, running, reading, listening to music and spending time with her family and friends.


Hayley Adams, Health Coach

Hayley was born and raised in Fort Worth,TX and received a Bachelors of Science degree from Texas A&M University in 2004. Her professional career began in the field of education where she was a teacher of various disciplines for nearly 10 years. Prior to having children, she was diagnosed with breast cancer at the tender age of 28. This abruptly forced her down the path of deciphering a treatment plan that addressed the root cause of her diagnosis while preserving her ability to have children but still assured her many more years of health and happiness. Shockingly, she soon discovered these were not the priorities of typical treatment protocols and realized she would have to seek out the brave practitioners willing to offer options outside the bounds of traditional western practices. Thus began her journey into the world of wellness and functional medicine. Having now been cancer free for over 9 years and the proud mother of a 3 year old son, she has dedicated her career to using the knowledge and resources she obtained to help others navigate their own story of healing. In 2019, she was ecstatic and honored to join McCall McPherson at Modern Thyroid Clinic, whom she considers one of the aforementioned brave practitioners so desperately needed in today’s health practices.