The Internet’s No-BS Doctor on Peptides, Longevity & the Health Trends to Ignore | Dr Karan Rajan

This week I'm joined by Dr Karan Rajan, NHS surgeon turned bestselling author and Chief of Science at Throne Science, for a conversation about optimisation culture: wearables, peptides, Bryan Johnson, and why more data isn't always better data.

What we explore together:
•His own health scare at 28, when a routine blood test uncovered fatty liver disease from a low-fibre diet

•Why "the illusion of health" might be the real cost of the wearable and wellness boom

•Bryan Johnson, colonoscopies, and why the most measured man in history still missed the basics

•The peptides debate: survivorship bias, zero human trial data, and what to actually ask before you try one

•A hospice nurse's deathbed regrets, and what they reveal about how we're really spending our time

•Creatine's kidney false alarm, and the simple blood test that solved it

•The "fever dream" that became Throne Science, and the mission to catch colon cancer early

Love, Sarah Ann 💛

My book 'Healthy Shouldn't Be This Hard': amazon.co.uk/Healthy-Shouldnt-Be-This-Hard-ebo…

This episode is sponsored by:

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PULSETTO: Vagus nerve stimulation for stress, sleep and calm.

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Dr Karan Rajan:
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Chapters

00:00 Introduction

01:05 Welcome + what's interesting Karan right now

02:19 His own health scare at 28: fatty liver, high cholesterol, low fibre

04:10 Wearables, optimisation culture and "orthosomnia"

05:56 Bryan Johnson: most measured human in history, still skipped his colonoscopy

14:51 Rick Rubin, Wilderness festival

16:12 "Illusion of health": wearables, data and fragility wrapped in a wellness aesthetic

19:09 The hospice nurse's deathbed regrets

20:23 The red cup trick, and why coffee helps you poop

24:22 Sugar substitutes and the cognitive-decline headline, unpacked

38:21 Wireless headphones and the cysts claim, debunked

42:54 Creatine and cognitive health

43:35 The kidney false alarm, and the test that solved it

49:47 Peptides: what they actually are

53:09 Survivorship bias and the total lack of human trial data

59:54 The Enhanced Games and performance enhancers

1:03:51 His own burnout and productivity

1:09:35 Why success and balance aren't compatible in this season of life

1:15:31 The Throne Science origin story

1:19:22 Sarah's own polyposis syndrome reveal

1:23:19 Closing: links and sign-off