Extend Podcast with Darshan Shah, MD

Fatigue, brain fog, weight gain, hair loss, low libido, high cholesterol, and a doctor who keeps telling you your labs look normal. For the millions of people walking around with an undetected or poorly managed thyroid condition, this is not just a frustrating experience but a dangerous one. Because what their doctor never told them is that the most important thyroid marker, the one that actually powers every cell in the body, is only being checked 4% of the time, which means the test they are relying on to rule out a thyroid problem is missing it almost every single time.
In this episode of Extend, I sat down with McCall McPherson for a conversation that is going to completely change the way you think about your thyroid, your labs, and why the treatment that 89% of thyroid patients are on may be the very reason they are still suffering. If you have ever been dismissed by your doctor despite feeling terrible, this episode is going to give you the language, the labs, and the clarity to finally get the answers you deserve.
McCall McPherson is a licensed Physician Associate, founder of Modern Thyroid Clinic, a practice with over 15,000 patients and hundreds of thousands of data points behind its approach, a TEDx speaker, and a 2024 Inc. 5000 honoree. She became one of the most sought after thyroid specialists in the country not just because of her clinical expertise but because she spent years as a thyroid patient herself, spending 16 hours a day in bed at 27 while being told her labs looked completely fine. There is nobody more qualified and nobody more personally invested in getting this right than she is.
WHAT'S DISCUSSED:
(2:12) The symptoms that signal a thyroid problem and why doctors keep dismissing them.

(4:38) Why every person with low testosterone needs to get their thyroid checked immediately.

(5:14) The three windows in a woman's life when thyroid disease risk spikes dramatically.

(6:12) What Hashimoto's actually is and why medicine is treating it completely backwards.

(11:46) Why TSH alone is missing the problem 96% of the time and what to ask for instead.

(16:38) What reverse T3 is and why elevated levels are silently blocking your thyroid hormone.

(35:15) Why subclinical hypothyroidism carries a 68% increased risk of heart attack and why medicine still is not treating it.

(38:53) McCall's personal story of spending 16 hours a day in bed at 27 while being told her labs looked completely normal.

Listen to this episode of Extend and finally understand why your labs have been coming back normal while your body has been telling you something is very wrong, what to ask your doctor to test, and what it actually takes to get your thyroid, your energy, and your life back.
 
Thank You to Our Sponsors:
 
Timeline: Timeline powered by Mitopure just dropped the price. Check it out at timeline.com/drshah and get an additional 20% off your first month with code DRSHAH. 

 
IM8: Try IM8 today with a 30-day money back guarantee. You can get 10% off your first order with code DRSHAH at im8health.com/discount/DRSHAH. 

 
Learn more about Dr. Shah:
Website: drshah.com
Clinic: next-health.com
Instagram: darshanshahmd  
Learn more about McCall McPherson: 
Instagram: @mccallmcphersonpa 
Modern Thyroid Clinic: www.modernthyroidclinic.com/
Modern Weight Loss: www.modernweightloss.com/

Biological aging is no longer just a concept tied to time. It is something we can now measure, track, and influence through data, lifestyle, and targeted interventions that directly impact how our cells function and age.
In this episode of Extend, we sit down with Dr. Kara Fitzgerald, functional medicine leader, researcher, and author, to unpack how diet and lifestyle can directly influence epigenetics and biological age. We break down the difference between chronological and biological aging, how epigenetic clocks work across organs and systems, and why aging may be driven by both environmental exposures and deeper programmed mechanisms.
We also explore how polyphenols, nutrient-dense diets, and emerging interventions like Yamanaka mimetics may begin to shift the trajectory of aging at the cellular level and open new pathways for extending healthspan and peak performance.
Dr. Kara Fitzgerald is a functional medicine physician, researcher, and author of Younger You, known for her pioneering clinical studies demonstrating how targeted nutrition and lifestyle interventions can reverse biological age and reshape long-term health outcomes.
 
What We Discuss:
(01:36) Aging, performance, and menopause

(05:01) Healthspan vs peak span

(08:39) The dark matter of nutrition

(11:36) Polyphenols and urolithin A

(13:12) Biological age and epigenetics

(15:41) Epigenetic clocks and measurement

(21:02) Exposomic aging

(25:03) Programmed aging

(28:20) Yamanaka factors

(33:24) Yamanaka mimetics

(36:29) Polyphenols and caloric restriction

(40:33) Nutrition and biological age reversal

 
Thank You to Our Sponsors:
IM8: Try IM8 today with a 30-day money back guarantee. You can get 10% off your first order with code DRSHAH at https://im8health.com/discount/DRSHAH. 
Momentous: Head to livemomentous.com/fiber and use code DRSHAH for up to 35% off your first order.
 
Learn more about Dr. Shah:
Website: drshah.com
Clinic: next-health.com
Instagram: darshanshahmd 



Learn more about Dr. Kara Fitzgerald:
Website: drkarafitzgerald.com 
Podcast: New Frontiers in Functional Medicine  
Webinars: webinars 
Instagram: drkarafitzgerald 
Facebook: Dr. Kara Fitzgerald  
You tube: @Drkarafitzgerald 
X: @kfitzgeraldnd 
Pubmed: Potential reversal of epigenetic age using a diet and lifestyle intervention: a pilot randomized clinical trial 
Pubmed: Potential reversal of biological age in women following an 8-week methylation-supportive diet and lifestyle program: a case series 
Pubmed: Dietary associations with reduced epigenetic age: a secondary data analysis of the methylation diet and lifestyle study

Mitochondrial decline is one of the most overlooked drivers of aging, impacting energy, muscle function, cognitive performance, and immune resilience long before symptoms become obvious. Many of the changes we associate with aging may actually stem from a loss of cellular efficiency and the body's ability to renew itself.
In this episode of Extend, I sit down with Dr. Anurag Singh, Chief Medical Officer at Timeline, to unpack the science behind urolithin A and how mitochondrial health shapes longevity. We break down how the gut microbiome influences cellular function, why mitophagy declines with age, and what clinical research shows about improving muscle strength, recovery, metabolic health, and immune function.
We also explore how targeted supplementation and lifestyle strategies can help restore mitochondrial quality and support long-term performance and resilience.
Dr. Anurag Singh is a physician-scientist with an M.D. in internal medicine and a Ph.D. in immunology, currently serving as Chief Medical Officer at Timeline, where he leads the development of advanced nutritional and skincare products focused on mitochondrial and cellular health.
 
What We Discuss:
(04:58) Drug vs nutraceutical and what urolithin A actually is

(06:23) Gut microbiome differences and why most people don't produce it

(08:11) How urolithin A is made from diet and polyphenols

(10:25) Effective dosing and supplementation strategy

(15:32) What mitochondria are and why they matter for aging

(21:26) Mitophagy and how mitochondrial quality declines over time

(23:43) Main drivers of mitochondrial damage

(26:24) How urolithin A supports cellular renewal

(28:55) Muscle aging, strength, and performance

(33:07) Clinical trial results in older and sedentary adults

(35:32) Effects on recovery in elite athletes

(37:07) Brain health and neurodegeneration research

(43:00) Immune system impact and inflammation

(47:29) When to start and how to think about supplementation




Thank You to Our Sponsors:
Timeline: Visit timeline.com/drshah for 20% off a subscription on top of the new starting price of $79.
 
Learn more about Dr. Shah:
Website: drshah.com
Clinic: next-health.com
Instagram: darshanshahmd 
 
Learn more about Dr. Anurag Singh:
Website: https://www.timeline.com/

Modern life is quietly accelerating biological aging, from posture and movement patterns to sleep disruption, chronic stress, and constant digital stimulation. Many of the symptoms people experience daily, like pain, fatigue, brain fog, and disconnection, may reflect a deeper misalignment with how the human body was designed to function.
In this episode of Extend, I sit down with Dr. Kavin Mistry, board-certified neuroradiologist and author of Primal Health Design, to unpack how modern lifestyles are reshaping our biology and accelerating aging. We break down how posture, movement, circadian rhythm, nutrition, and environment influence brain and spine health, and why reconnecting with our primal design is essential for long-term resilience and performance.
We also explore how daily practices like morning sunlight, grounding, deep work, and intentional routines can help restore alignment with your biology and create more energy, clarity, and longevity in a fast-moving, AI-driven world.
Dr. Kavin Mistry is a board-certified neuroradiologist, author, and thought leader in longevity and human performance, known for developing the Primal Health Design framework to help individuals reconnect with their biology and reverse the hidden effects of modern living.
What We Discuss:
(05:04) Seeing accelerated biological aging in brain and spine scans

(06:02) Childhood exposure to primal tribes and longevity insights

(10:19) Tech neck, posture, and modern spinal degeneration

(12:09) Nerve compression, numbness, and daily symptoms

(15:03) Primal posture and how alignment reduces aging

(18:07) Strength training, hanging, and back development

(21:17) Deep squat and reversing sedentary damage

(24:14) Walking, movement, and daily activity patterns

(25:01) Grounding, inflammation, and connection to earth

(28:01) Morning sunlight and circadian rhythm optimization

(31:27) Sleep, stress, and parasympathetic recovery

(32:11) Nutrition, microbiome diversity, and prebiotics

(36:44) Stillness, presence, and flow state

(42:20) Tribe, relationships, and loneliness in modern life

(48:44) Purpose, service, and greater cause

(51:02) Finite life awareness and long-term decision making

(56:07) AI, time leverage, and becoming more human

(59:47) Morning and night routines as the foundation


Thank You to Our Sponsors:
IM8: Try IM8 today with a 30-day money back guarantee. You can get 10% off your first order with code DRSHAH at https://im8health.com/discount/DRSHAH. 
Momentous: Head to livemomentous.com/fiber and use code DRSHAH for up to 35% off your first order.
 
Learn more about Dr. Shah:
Website: drshah.com
Clinic: next-health.com
Instagram: darshanshahmd 

 
Learn more about Dr. Mistry:
Website: kavinmistrymd.com 
Instagram: kavinmistry.md 
LinkedIn: Kavin Mistry MD
YouTube: @kavinmistrym.d

Allergies, chronic inflammation, and constant exposure to environmental toxins are reshaping how our immune system functions, often in ways that go unnoticed until symptoms appear. What many people see as isolated issues like gut problems, skin reactions, or fatigue may actually reflect a deeper immune imbalance.
In this episode of Extend, I sit down with Dr. Tania Elliott, double board-certified physician in internal medicine and allergy and immunology, to unpack how the immune system operates across infection defense, hypersensitivity, and autoimmunity, and how modern exposures like microplastics, synthetic chemicals, and ultra-processed products are disrupting this balance. We break down how chronic inflammation begins, why gut health is central to immune regulation, and how everyday products in your home may be silently driving immune dysfunction.
We also explore how simple, high-impact changes like reducing toxin exposure, improving indoor air quality, and retraining the immune system through targeted therapies can restore balance and reduce long-term disease risk.
Dr. Tania Elliott is a double board-certified physician in internal medicine and allergy and immunology, focused on helping patients understand immune health, reduce toxic exposures, and apply practical, science-backed strategies to improve resilience, longevity, and overall well-being.
What We Discuss:
(09:07) Immune system explained in three core functions

(10:42) How chronic inflammation begins

(11:13) Gut health and microbiome disruption

(12:50) Signs your immune system is out of balance

(15:39) Environmental toxins and ultra-processed foods

(17:39) Skincare, sunscreen, and endocrine disruptors

(21:33) Microplastics and hidden daily exposure

(24:00) Teflon, PFAS, and long-term health risks

(30:01) Building a healthier home environment

(40:07) Why allergies are increasing

(41:40) Hygiene hypothesis and early exposure

(45:10) Peanut allergy and early introduction

(50:01) Recurrent infections and immune deficiency

(51:21) Immune testing and biomarkers

(52:30) IVIG therapy and immune support

(57:11) Allergy immunotherapy and long-term solutions


 
Thank You to Our Sponsors:
Function Health: Learn more and join using my link. Visit www.functionhealth.com/drshah and use gift code DRSHAH25 for a $25 credit toward your membership. 
Momentous: Head to www.livemomentous.com/fiber and use code DRSHAH for up to 35% off your first order. 
 
Learn more about Dr. Shah:
Website: drshah.com
Clinic: next-health.com
Instagram: darshanshahmd 
 
Learn more about Dr. Tania Elliott:
Website: Dr. Tania Elliott
Instagram: drtaniaelliott
LinkedIn: Tania Elliott, MD