#373 – Thyroid function and hypothyroidism: why current diagnosis and treatment fall short for many, and how new approaches are transforming care | Antonio Bianco, M.D., Ph.D.
Release Date: 11/17/2025
The Peter Attia Drive
Antonio Bianco is a world-renowned physician-scientist and expert in thyroid physiology and metabolism. In this episode, Antonio explores the complex biology of thyroid hormone production, conversion, and regulation—highlighting how deiodinase enzymes modulate hormone activity at the tissue level and why that matters for interpreting lab results. He discusses the shortcomings of relying solely on TSH as a marker of thyroid function, the ongoing debate around combination therapy with T3 and T4 versus standard T4 treatment, and how genetics, tissue sensitivity, and individual variability...
info_outlineThe Peter Attia Drive
In this “Ask Me Anything” (AMA) episode, Peter breaks down the science of dietary fiber, moving beyond the blanket advice to “eat more fiber” to uncover what it actually does in the body and where its benefits are truly supported by evidence. He explains how different types of fiber—soluble, insoluble, viscous, and fermentable—affect digestion, satiety, weight management, and glycemic control, and compares their impact to other, more potent metabolic tools. Peter also examines how certain fibers influence lipid metabolism and cardiovascular risk, evaluates the strength of...
info_outlineThe Peter Attia Drive
Sally Greenwald is an OB-GYN who specializes in women’s sexual health from a hormonal and physiologic perspective, with expertise spanning desire, arousal, pelvic floor function, contraception, and menopause care. In this episode, she explains why sexual health is a vital component of overall well-being, exploring topics such as the drivers of desire, the anatomy of sexual function, myths and realities around orgasm, and the role of hormones in perimenopause and menopause. She also covers vaginal and pelvic health, pain with sex, evidence-based therapies for low desire and arousal, how...
info_outlineThe Peter Attia Drive
In this special episode, Peter provides a comprehensive introduction to longevity, perfect for newcomers or those looking to refresh their knowledge. He lays out the foundational concepts of lifespan, healthspan, and the marginal decade. Additionally, Peter discusses the four main causes of death and their prevention, as well as detailing the five key strategies in his longevity toolkit to improve lifespan and healthspan. Detailed show notes provide links for deeper exploration of these topics, making it an ideal starting point for anyone interested in understanding and improving their...
info_outlineThe Peter Attia Drive
In this “Ask Me Anything” (AMA) episode, Peter revisits the “proven, promising, fuzzy, noise, nonsense” scale and applies it to a variety of popular topics. He begins with a refresher on what each category represents before classifying a range of interventions based on the strength of their supporting evidence. The conversation spans three main areas: drugs for geroprotection (including GLP-1 receptor agonists, SGLT2 inhibitors, methylene blue, and telomere-lengthening supplements), the use of low-dose aspirin for cardiovascular disease prevention, and strategies to improve muscle...
info_outlineThe Peter Attia Drive
Rhonda Patrick is a scientist, health educator, and host of the FoundMyFitness podcast whose work explores the intersection of nutrition, aging, and disease prevention. In this episode, Rhonda joins Peter for part two of his deep dive on protein, continuing last week’s discussion with David Allison and expanding the conversation to include creatine supplementation and sauna use. She discusses why the current RDA for protein is insufficient, how much more is needed to maintain muscle mass and prevent frailty, how activity level and aging influence protein requirements through mechanisms...
info_outlineThe Peter Attia Drive
David Allison is a world-renowned scientist and award-winning scientific writer who has spent more than two decades at the forefront of obesity research. In this episode, David joins for his third appearance on The Drive to bring clarity to one of the most contentious topics in modern nutrition—protein. He explores the historical pattern of demonizing macronutrients, the origins and limitations of the RDA for protein, and what the evidence really says about higher protein intake, muscle protein synthesis, and whether concerns about harm are supported by actual data. He also discusses the...
info_outlineThe Peter Attia Drive
In this special episode of The Drive, Peter addresses the recent headlines linking acetaminophen (Tylenol) use during pregnancy to autism in exposed children. Recognizing the confusion these claims have sparked among patients, listeners, and the broader public, Peter uses this episode to provide a framework for thinking critically about complex conditions and the research related to them. He highlights the dramatic rise in autism diagnoses over recent decades, noting that multifactorial conditions rarely have a single cause, and emphasizes the importance of resisting oversimplified...
info_outlineThe Peter Attia Drive
Joe Liemandt is a software entrepreneur turned education reformer who left Stanford in 1989 to found Trilogy, a highly profitable private software company, before pivoting to transforming K-12 learning. In this episode, Joe shares how he transitioned from leading a global software enterprise to becoming principal of Alpha School, where his focus is building a mastery-based, individualized education model that leverages AI as the missing infrastructure for large-scale change. He details the shortcomings of traditional K-12 education, explains how Alpha replaces conventional seat time with...
info_outlineThe Peter Attia Drive
In this special episode of The Drive, Peter hosts a strength and conditioning roundtable with three experts in the field—Gabrielle Lyon, Jeff Cavaliere, and Mike Boyle. Together they explore why maintaining muscle mass, strength, and power is essential for healthspan and longevity, and examine how resistance training supports metabolic resilience and injury prevention across the lifespan. The conversation covers practical strategies for getting started and staying consistent, the importance of a protein-centered diet tailored to age and activity level, and approaches to resistance...
info_outlineView the Show Notes Page for This Episode
Become a Member to Receive Exclusive Content
Sign Up to Receive Peter’s Weekly Newsletter
Antonio Bianco is a world-renowned physician-scientist and expert in thyroid physiology and metabolism. In this episode, Antonio explores the complex biology of thyroid hormone production, conversion, and regulation—highlighting how deiodinase enzymes modulate hormone activity at the tissue level and why that matters for interpreting lab results. He discusses the shortcomings of relying solely on TSH as a marker of thyroid function, the ongoing debate around combination therapy with T3 and T4 versus standard T4 treatment, and how genetics, tissue sensitivity, and individual variability influence thyroid hormone metabolism. The conversation also examines how hypothyroidism affects energy, mood, cognition, and longevity; why some patients remain symptomatic despite “normal” labs; and how future research could reshape treatment paradigms.
We discuss:
- How the thyroid produces, stores, and activates hormones like T4 and T3 to finely regulate thyroid activity [2:45];
- How fasting alters thyroid hormones to conserve energy [12:45];
- Action of the deiodinases: how D1, D2, and D3 enzymes control the activation and inactivation of thyroid hormones [19:15];
- The normal function of thyroid hormone and the roles of the hypothalamus, pituitary gland, and deiodinases in maintaining hormonal balance [23:30];
- Why understanding thyroid physiology is essential for proper diagnosis and treatment of hypothyroidism [33:45];
- Testing for thyroid hormones: understanding free vs. total levels, the limitations of current T3 assays, best practices, and more [36:00];
- Genetic and sex-based variability in thyroid hormone regulation and their limited clinical significance [43:45];
- Hyperthyroidism: causes, symptoms, diagnosis, and treatment options [46:00];
- Hypothyroidism: diagnosis and autoimmune causes of hypothyroidism [56:30];
- More on hypothyroidism: diagnostic biomarkers, antibody patterns, and non-autoimmune presentations [1:05:00];
- Thyroid hormone replacement therapy [1:15:15];
- More on thyroid replacement strategies: exploring the evidence gaps, mortality signals, effects on lipids, and more [1:28:00];
- Hypothyroidism basics: causes, antibody implications (including pregnancy), and how to make the diagnosis before choosing therapy [1:35:15];
- Thyroid medication: compounded controlled-release T3, brand name versus generic, and what Antonio prescribes to newly diagnosed hypothyroid patients [1:42:45];
- Redefining treatment success: why normalizing TSH isn’t always enough for patients with hypothyroidism [1:54:45];
- Case studies: analysis of two unusual cases of thyroid disease [1:57:00];
- Dangers of supplementing with high levels of iodine, and female-specific risk of thyroid disease [2:05:45];
- Case study of a patient who presents with elevated TSH but no symptoms [2:09:30];
- How future research could reshape treatment, and Antonio’s new book called “Rethinking Hypothyroidism” [2:13:15]; and
- More.
Connect With Peter on Twitter, Instagram, Facebook and YouTube