159: Dr. Anurag Singh: Urolithin A, Mitophagy, and Mitochondrial Health

Apr 28, 2026

Dr. Anurag Singh, physician-scientist and Chief Medical Officer at Timeline, discusses urolithin A and mitochondrial health. He explains how the gut microbiome makes urolithin A, why many people do not produce it, and practical dosing choices. They cover mitophagy, drivers of mitochondrial damage, muscle and athletic recovery data, emerging brain and immune research, and when to consider supplementation.

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INSIGHT

Mitochondria Are Maternal Power Plants

Mitochondria are the cell's power plants, with their own maternal-inherited DNA and bacterial origin.
High-energy tissues (brain, muscle, heart) contain thousands of mitochondria and are most affected by mitochondrial decline.

INSIGHT

Mitophagy Cleans Out Damaged Mitochondria

Three mechanisms restore mitochondrial health: biogenesis, fusion/fission, and mitophagy.
Aging shifts the balance toward damaged mitochondria, making mitophagy (targeted mitochondrial autophagy) crucial to clear the backlog.

INSIGHT

Urolithin A Activates Mitophagy Then Biogenesis

Urolithin A uniquely activates mitophagy, restarting cellular cleanup and enabling later biogenesis.
Trials show mitophagy signals within 1–2 weeks and biogenesis markers (PGC-1α) by ~1 month in muscle tissue.

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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/