Secretagogues and growth‑hormone mimetics explained

The peptide and GLP-1 conversation has reached a fever pitch. Growth-hormone-releasing peptides are being marketed as longevity tools, GLP-1s are being treated as a default rather than a last resort, and a wellness aesthetic of higher IGF-1, more muscle, and less fat is being sold as the route to a longer life. In this episode, I sit down with Dr Valter Longo, Professor of Gerontology at USC and Director of the USC Longevity Institute, to look at what the data actually says.

Valter developed the Fasting-Mimicking Diet, has led foundational work on the growth hormone, IGF-1, insulin, and TOR axis across yeast, mice, and humans, and runs non-profit longevity foundation clinics in Europe and the US. He calls himself the anti-biohacker and makes the case using the totality of evidence rather than the loudest claim.

What we cover:

• The peptide boom and why every line of evidence cuts the other way
• The body composition reality of GLP-1s after 3 to 4 years
• The optimal IGF-1 range and how to land there with food and timing
• The Fasting-Mimicking Diet across more than 47 clinical trials, including the biological-age reduction studies
• The Harvard plant-versus-animal protein data, properly read
• A grounded case against ketogenic patterns for longevity and what to eat instead

If this conversation lands, a quick rating or review on Apple Podcasts or Spotify makes a real difference.

To follow more of Dr Valter Longo's work, visit his website, find him on Instagram, and explore the work of the Create Cures Foundation, the Valter Longo Foundation, the Longevity Technology Institute, and the European Longevity Institute through his published research and his book The Longevity Diet.

• Intro (00:00)
• The Peptide Boom and What Is Actually Being Sold (00:01)
• GLP-1s: 92 Per Cent Drop-Out and the Body Composition Math (00:02)
• The Fasting-Mimicking Diet Reverses Western-Diet Damage (00:13)
• Snell, Ames, and Laron Dwarf Mice (00:18)
• The Laron Syndrome Cohort in Ecuador (00:24)
• Acromegaly and the Cost of High Growth Hormone (00:28)
• The Optimal IGF-1 Range: 120 to 160 ng/mL (00:50)
• Plant vs Animal Protein, Properly Read (00:57)
• The Anti-Keto Case from Okinawa to Loma Linda (01:08)
• Stanford Crohn's, Miami UC, and Rome Kidney Disease (01:22)
• Biological Age Reduction After Three FMD Cycles (01:25)
• FMD Safety Across More Than a Million Users (01:31)
• The Longevity Diet: Eat More, Eat Better (01:43)

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Simon Hill, MSc, BSc (Hons)

• Creator of theproof.com
• Host of The Proof with Simon Hill
• Author of The Proof is in the Plants

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