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/