Dr. Brendan McCarthy
Welcome! 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. Through successful case after successful case, Dr. McCarthy has been dedicated to hormone balance, healthy metabolism, and the best quality of life. Dr. McCarthy’s hallmark 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, insomnia and now wants to share his knowledge to the viewers with his podcast. Join the discussion, ask questions, and welcome to the podcast!
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Get to Know Me
Dr. McCarthy is internationally recognized as an expert in hormone replacement therapy. He has lectured physicians and pharmacists on topics such as weight loss, infertility, hormone replacement therapy, nutritional therapy and more.
Often we look at the qualifications of a physician to help us choose a doctor, but a good doctor is more than just credentials and titles. A doctor needs to be compassionate and empathic. Dr. McCarthy has built his practice upon his dedication to each individual patient. He is passionate about his work and committed to educating his patients on their medical conditions so they can gain control of their health.
Episodes
4 days ago
4 days ago
Unexplained infertility, PMS, and low progesterone are often dismissed when labs fall “within range.” In this episode, Dr. Brendan McCarthy explains why prolactin may be the missing piece.
Learn how mildly elevated prolactin can suppress ovulation, lower progesterone, and impact fertility—even when labs appear normal. We also discuss common causes, symptoms, the role of stress and medications, and why diet (including gluten sensitivity) may matter.
This episode focuses on precision medicine, not fear—helping you understand what standard reference ranges often miss.
Citations: Research — Prolactin and Breast Cancer Risk
Below are key epidemiologic and review papers that inform the discussion in this episode regarding prolactin and breast biology. These studies look at associations, not simple cause-and-effect relationships, and help explain why prolactin shows up in breast health conversations.
Meta-analysis: circulating prolactin and breast cancer risk
Wang M, et al. (2016).Plasma prolactin and breast cancer risk: a meta-analysis.Cancer Causes & Control.
This meta-analysis pooled data from multiple observational studies comparing women with higher versus lower circulating prolactin levels. Across studies, higher prolactin levels were associated with a modest but statistically significant increase in breast cancer risk. The association was most evident in postmenopausal women and in hormone-receptor–positive tumors.
This helps explain why prolactin is considered a relevant growth signal in breast tissue rather than just a “lactation hormone.”
Systematic review and meta-analysis: prolactin levels across breast cancer cohorts
Aranha AF, et al. (2022).Impact of prolactin levels in breast cancer: a systematic review and meta-analysis.Endocrine-Related Cancer.
This more recent systematic review and meta-analysis evaluated circulating prolactin levels across breast cancer populations and control groups. Elevated prolactin levels were associated with higher breast cancer occurrence, with stronger associations seen in invasive cancers and hormone-receptor–positive disease.
This paper adds weight to the idea that prolactin participates in breast biology in ways that matter clinically, even outside of pregnancy and breastfeeding.
Prospective cohort studies: prolactin measured before diagnosis
Tworoger SS, et al. (2004; 2006).Prospective analyses from large cohorts including the Nurses’ Health Study.
In these studies, prolactin was measured years before any breast cancer diagnosis. Women with higher prolactin levels had a higher likelihood of developing breast cancer later, particularly estrogen-receptor–positive tumors in postmenopausal women.
Because prolactin was measured before cancer developed, these studies help clarify timing and reduce the concern that elevated prolactin is simply a consequence of disease.
Mechanistic context (supportive background)
Experimental and translational studies show that prolactin receptor signaling influences mammary epithelial cell growth, differentiation, and interaction with estrogen signaling pathways.
This provides a biologic backdrop for why epidemiologic associations between prolactin and breast cancer risk keep appearing across different study designs.
How to read this as a clinician or patient
These data do not mean prolactin “causes” breast cancer in a simple or deterministic way. What they do show is that prolactin is an active hormone in breast tissue, and chronically higher levels are consistently associated with changes in breast risk profiles across large populations.
That’s why prolactin deserves attention in conversations about fertility, breast symptoms, and long-term hormonal signaling—not fear, and not dismissal.
Dr. Brendan McCarthy is the founder and Chief Medical Officer of Protea Medical Center in Arizona. With over two decades of experience, he’s helped thousands of patients navigate hormonal imbalances using bioidentical HRT, nutrition, and root-cause medicine. He’s also taught and mentored other physicians on integrative approaches to hormone therapy, weight loss, fertility, and more. If you’re ready to take your health seriously, this podcast is a great place to start.
👇 Tap Subscribe to learn more about what’s actually happening in your body, and what to do about it.
📘 Read Dr. McCarthy’s Book: Jump Off the Mood Swing – A Sane Woman’s Guide to Her Crazy Hormones https://www.amazon.com/Jump-Off-Mood-Swing-Hormones/dp/0999649604
📲 Follow Dr. McCarthy:
Instagram: @drbrendanmccarthy
TikTok: @drbrendanmccarthy
Website: www.protealife.com
💬 Got a question or topic for a future episode? Let us know in the comments!
Wednesday Jan 28, 2026
Wednesday Jan 28, 2026
In this episode of our progesterone series (Episode 5), Dr. Brendan McCarthy — Chief Medical Officer of Protea Medical Center in Tempe, Arizona — breaks down the often-misunderstood relationship between stress, ovulation, progesterone, and cortisol.
We explore the concept commonly referred to as the “progesterone steal” and why this term can be misleading. Rather than hormones being “stolen,” Dr. McCarthy explains how the body intelligently reroutes hormone production under stress to prioritize survival over reproduction.
This episode covers:
Why the body must feel safe to ovulate and produce progesterone
How chronic stress impacts PMS, fertility, and cycle regularity
The truth about cortisol (and why it isn’t the villain it’s often made out to be)
Why low progesterone is not a personal failure or flaw
Why you can’t medicate someone out of stress — and what good medicine actually looks like
This conversation is about biology, not blame. Your body is not broken — it’s responding exactly as designed.
Dr. Brendan McCarthy is the founder and Chief Medical Officer of Protea Medical Center in Arizona. With over two decades of experience, he’s helped thousands of patients navigate hormonal imbalances using bioidentical HRT, nutrition, and root-cause medicine. He’s also taught and mentored other physicians on integrative approaches to hormone therapy, weight loss, fertility, and more. If you’re ready to take your health seriously, this podcast is a great place to start.
👇 Tap Subscribe to learn more about what’s actually happening in your body, and what to do about it.
📘 Read Dr. McCarthy’s Book: Jump Off the Mood Swing – A Sane Woman’s Guide to Her Crazy Hormones https://www.amazon.com/Jump-Off-Mood-Swing-Hormones/dp/0999649604
📲 Follow Dr. McCarthy:
Instagram: @drbrendanmccarthy
TikTok: @drbrendanmccarthy
Website: www.protealife.com
💬 Got a question or topic for a future episode? Let us know in the comments!
Wednesday Jan 21, 2026
Wednesday Jan 21, 2026
In this episode, Dr. Brendan McCarthy, Chief Medical Officer of Protea Medical Center, explains why progesterone delivery systems matter—and how different routes change what progesterone actually does in the body.
Part 4 of the progesterone series covers oral, topical, vaginal, rectal, injectable, and sublingual progesterone, breaking down which methods affect the brain, uterus, and breast tissue—and why choosing the right route is critical.
If progesterone hasn’t worked for you in the past, the issue may not be the dose, but how it was delivered.
This episode focuses on education, patient agency, and thoughtful hormone care—no shortcuts, no selling.
Subscribe for more in-depth conversations on hormones and women’s health, and share with someone who may benefit.
Dr. Brendan McCarthy is the founder and Chief Medical Officer of Protea Medical Center in Arizona. With over two decades of experience, he’s helped thousands of patients navigate hormonal imbalances using bioidentical HRT, nutrition, and root-cause medicine. He’s also taught and mentored other physicians on integrative approaches to hormone therapy, weight loss, fertility, and more. If you’re ready to take your health seriously, this podcast is a great place to start.
👇 Tap Subscribe to learn more about what’s actually happening in your body, and what to do about it.
📘 Read Dr. McCarthy’s Book: Jump Off the Mood Swing – A Sane Woman’s Guide to Her Crazy Hormones https://www.amazon.com/Jump-Off-Mood-Swing-Hormones/dp/0999649604
📲 Follow Dr. McCarthy:
Instagram: @drbrendanmccarthy
TikTok: @drbrendanmccarthy
Website: www.protealife.com
💬 Got a question or topic for a future episode? Let us know in the comments!
Wednesday Jan 14, 2026
Wednesday Jan 14, 2026
If progesterone makes you feel wired, anxious, angry, emotional, or unable to sleep, this episode is for you.
In this deeply important continuation of our reverse responding series, Dr. Brendan McCarthy—Chief Medical Officer of Protea Medical Center—returns to clarify what was missing in Episode 3C and to walk you through the real physiology, compassion, and treatment strategy behind reverse responding.
Reverse responding is not intolerance, weakness, anxiety, noncompliance, or failure. It is an adaptive response rooted in threat-state physiology, chronic stress, and lived experience. Your body is not broken—it is protecting you.
In this episode, Dr. McCarthy covers:
What reverse responding actually is (and what it is not)
The difference between sulfation and 5-alpha pathways
Why labs often miss this entirely
Why “just more progesterone” makes things worse
How trauma, chronic stress, and safety shape hormone response
The importance of earning permission from the nervous system
Practical treatment pillars:
Glycemic stability
Circadian safety and sleep rhythm
Reducing inflammatory load
Gentle nervous system regulation
Slow, low, respectful progesterone onboarding
Supplement strategies used clinically (and what to avoid)
Most importantly, this episode is a reminder:You are not the problem. Your body is doing something intelligent.
Dr. Brendan McCarthy is the founder and Chief Medical Officer of Protea Medical Center in Arizona. With over two decades of experience, he’s helped thousands of patients navigate hormonal imbalances using bioidentical HRT, nutrition, and root-cause medicine. He’s also taught and mentored other physicians on integrative approaches to hormone therapy, weight loss, fertility, and more. If you’re ready to take your health seriously, this podcast is a great place to start.
👇 Tap Subscribe to learn more about what’s actually happening in your body, and what to do about it.
📘 Read Dr. McCarthy’s Book: Jump Off the Mood Swing – A Sane Woman’s Guide to Her Crazy Hormones https://www.amazon.com/Jump-Off-Mood-Swing-Hormones/dp/0999649604
📲 Follow Dr. McCarthy:
Instagram: @drbrendanmccarthy
TikTok: @drbrendanmccarthy
Website: www.protealife.com
💬 Got a question or topic for a future episode? Let us know in the comments!
Wednesday Jan 07, 2026
Wednesday Jan 07, 2026
Dr. Brendan McCarthy, Chief Medical Officer of Protea Medical Center in Tempe, Arizona, brings closure to an important and often misunderstood topic: progesterone reverse responders.
Some women take progesterone expecting calm, better sleep, and emotional balance — but instead experience anxiety, irritability, agitation, or feeling “wired but tired.” These responses are real, not imagined, and not a personal failure.
In this episode, Dr. McCarthy explains:
What progesterone reverse responding actually is (and what it is not)
Why this reaction is not an intolerance or allergy
How progesterone’s downstream metabolites affect the brain
The difference between the 5-alpha reductase pathway and sulfation pathways
Why labs can look “normal” while symptoms feel anything but
Common mistakes providers make (pushing the dose, “waiting it out,” or masking symptoms)
Why stress physiology plays a major role
How thoughtful, patient-centered medicine can help women heal
Most importantly, this episode emphasizes listening to women, validating lived experiences, and practicing medicine with curiosity, humility, and care.
Dr. Brendan McCarthy is the founder and Chief Medical Officer of Protea Medical Center in Arizona. With over two decades of experience, he’s helped thousands of patients navigate hormonal imbalances using bioidentical HRT, nutrition, and root-cause medicine. He’s also taught and mentored other physicians on integrative approaches to hormone therapy, weight loss, fertility, and more. If you’re ready to take your health seriously, this podcast is a great place to start.
👇 Tap Subscribe to learn more about what’s actually happening in your body, and what to do about it.
📘 Read Dr. McCarthy’s Book: Jump Off the Mood Swing – A Sane Woman’s Guide to Her Crazy Hormones https://www.amazon.com/Jump-Off-Mood-Swing-Hormones/dp/0999649604
📲 Follow Dr. McCarthy:
Instagram: @drbrendanmccarthy
TikTok: @drbrendanmccarthy
Website: www.protealife.com
💬 Got a question or topic for a future episode? Let us know in the comments!
Wednesday Dec 31, 2025
Wednesday Dec 31, 2025
In this episode of the podcast, Dr. Brendan McCarthy—Chief Medical Officer of Protea Medical Center in Tempe, Arizona—continues his in-depth progesterone series with a deep dive into reverse responders and an often-overlooked mechanism: hormone sulfation.
Many women take progesterone expecting better sleep, calmer moods, and reduced anxiety—yet feel more alert, only mildly calmer, or see no benefit at all. This episode explains why that doesn’t mean progesterone is wrong for you.
Dr. McCarthy breaks down:
What progesterone reverse responding really is
The difference between 5-alpha reductase pathways and sulfation
How the brain uses sulfation to buffer stress and trauma
Why progesterone may be stored instead of calming the nervous system
The role of chronic stress, PTSD, perimenopause, and hormone volatility
Why higher doses can make things worse
How thoughtful, low-dose, individualized hormone therapy actually works
Dr. Brendan McCarthy is the founder and Chief Medical Officer of Protea Medical Center in Arizona. With over two decades of experience, he’s helped thousands of patients navigate hormonal imbalances using bioidentical HRT, nutrition, and root-cause medicine. He’s also taught and mentored other physicians on integrative approaches to hormone therapy, weight loss, fertility, and more. If you’re ready to take your health seriously, this podcast is a great place to start.
👇 Tap Subscribe to learn more about what’s actually happening in your body, and what to do about it.
📘 Read Dr. McCarthy’s Book: Jump Off the Mood Swing – A Sane Woman’s Guide to Her Crazy Hormones https://www.amazon.com/Jump-Off-Mood-Swing-Hormones/dp/0999649604
📲 Follow Dr. McCarthy:
Instagram: @drbrendanmccarthy
TikTok: @drbrendanmccarthy
Website: www.protealife.com
💬 Got a question or topic for a future episode? Let us know in the comments!
Wednesday Dec 17, 2025
Wednesday Dec 17, 2025
Have you taken progesterone expecting calm, better sleep, or relief from PMS… only to feel more anxious, wired, or worse overall? You are not a failure—and progesterone is not failing you. Your body is responding exactly as physiology dictates. The issue is how progesterone is being delivered and metabolized.
In this episode, Dr. McCarthy explains:
What it means to be a progesterone reverse responder
How progesterone normally supports mood and brain chemistry through allopregnanolone
Why some women experience paradoxical anxiety, insomnia, or agitation
The role of the 5-alpha reductase pathway in progesterone metabolism
Why oral progesterone can overwhelm the brain in certain women
How PCOS, topical testosterone, stress, insulin resistance, and ultra-processed diets can amplify reverse responses
Why kinetics and delivery method matter just as much as dosage
Dr. Brendan McCarthy is the founder and Chief Medical Officer of Protea Medical Center in Arizona. With over two decades of experience, he’s helped thousands of patients navigate hormonal imbalances using bioidentical HRT, nutrition, and root-cause medicine. He’s also taught and mentored other physicians on integrative approaches to hormone therapy, weight loss, fertility, and more. If you’re ready to take your health seriously, this podcast is a great place to start.
👇 Tap Subscribe to learn more about what’s actually happening in your body, and what to do about it.
📘 Read Dr. McCarthy’s Book: Jump Off the Mood Swing – A Sane Woman’s Guide to Her Crazy Hormones https://www.amazon.com/Jump-Off-Mood-Swing-Hormones/dp/0999649604
📲 Follow Dr. McCarthy:
Instagram: @drbrendanmccarthy
TikTok: @drbrendanmccarthy
Website: www.protealife.com
💬 Got a question or topic for a future episode? Let us know in the comments!
Wednesday Dec 10, 2025
Wednesday Dec 10, 2025
In Episode 2 of this deep-dive hormone series, Dr. Brendan McCarthy—Chief Medical Officer of Protea Medical Center in Tempe, AZ—breaks down the part of progesterone almost no one talks about: its powerful role as a brain hormone.
Most women are only taught that progesterone is about fertility and uterine lining. But the truth?Progesterone is a neurosteroid that influences your amygdala, hippocampus, and prefrontal cortex—three key brain regions that shape your stress response, emotional stability, sleep, memory, and self-trust.
This episode covers:✔️ Why perimenopause makes your brain feel “out of control”✔️ The link between progesterone decline and anxiety, irritability, depression, night sweats, and brain fog✔️ How progesterone converts to allopregnanolone (your brain’s natural calming signal)✔️ Why women under chronic stress or in their late 30s–40s feel symptoms more intensely✔️ How hormonal imbalance impacts memory, decision-making, and emotional regulation✔️ Why you’re not broken—and what real validation and proper care looks like
Dr. Brendan McCarthy is the founder and Chief Medical Officer of Protea Medical Center in Arizona. With over two decades of experience, he’s helped thousands of patients navigate hormonal imbalances using bioidentical HRT, nutrition, and root-cause medicine. He’s also taught and mentored other physicians on integrative approaches to hormone therapy, weight loss, fertility, and more. If you’re ready to take your health seriously, this podcast is a great place to start.
👇 Tap Subscribe to learn more about what’s actually happening in your body, and what to do about it.
📘 Read Dr. McCarthy’s Book: Jump Off the Mood Swing – A Sane Woman’s Guide to Her Crazy Hormones https://www.amazon.com/Jump-Off-Mood-Swing-Hormones/dp/0999649604
📲 Follow Dr. McCarthy:
Instagram: @drbrendanmccarthy
TikTok: @drbrendanmccarthy
Website: www.protealife.com
💬 Got a question or topic for a future episode? Let us know in the comments!