In this episode, Matt delves into the curious and cautionary tale of Delta Sleep-Inducing Peptide (DSIP), once hailed as a potential miracle cure for insomnia. In the 1970s, researchers were on a quest for a single "somnogenic molecule" that could act as the brain's natural sleep switch. A Swiss team believed they had found it, isolating a peptide that appeared to rapidly induce deep, slow-wave sleep when injected into animals. This initial excitement led to bold claims and sparked decades of research into what seemed to be a revolutionary breakthrough in sleep science.

However, the promising discovery soon began to unravel under closer scientific scrutiny. Red flags emerged, including the inability to find the gene that coded for DSIP and the peptide's extreme fragility, which prevented it from effectively reaching the brain. When rigorous, placebo-controlled human trials were finally conducted, the results were profoundly disappointing, showing no significant clinical benefit over a placebo. Ultimately, the story of DSIP serves as a powerful lesson on the dangers of scientific overconfidence, the critical importance of replication and skepticism, and the profound complexity of sleep regulation, reminding us that there is no single "magic bullet" for a good night's sleep.

Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.

In a supplement industry where trust is critical, Matt uses podcast partner Puori. Their protein powders are free from hormones, GMOs, and pesticides, with every single batch third-party tested for over 200 contaminants. For protein you can trust, save 20% at puori.com/mattwalker.

As always, if you have thoughts or feedback you’d like to share, please reach out to Matt:

Matt: Instagram @drmattwalker, X @sleepdiplomat,

YouTube: https://www.youtube.com/channel/UCA3FB1fOtY4Vd8yqLaUvolg

Matt explores the human capacity for echolocation this week, dismantling the myth that this "biological sonar" is exclusive to animals. Revealing how peer-reviewed research shows all human brains possess the neural hardware to "see" with sound, Matt explains the physics of how sound creates detailed acoustic maps of our environment and introduces the brain's remarkable plasticity, setting the stage for this incredible sensory adaptation.

The episode features stories of pioneers like Daniel Kish, who use echolocation to navigate with astonishing precision. Matt discusses groundbreaking studies from UC Berkeley and Durham University, where brain scans revealed the visual cortex rewires itself to process sound as spatial information. This evidence proves echolocation is not a rare gift but a learnable skill, forcing a reevaluation of the limits of human perception and the brain's adaptive power.

Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.

As a huge supporter of mission-driven companies, Matt recommends new partner Branch Basics. Their plant- and mineral-based ‘The Concentrate’ is tough on kitchen grease yet gentle enough for baby toys, helping you create a toxin-free home. Get 15% off with code MattWalker at branchbasics.com/mattwalker.

Another partner, AG1, is one that Matt relies upon for his foundational nutrition. Their new science-backed Next Gen formula features upgraded probiotics, vitamins, and minerals. Start your subscription today to get a FREE bottle of Vitamin D3+K2 and 5 free travel packs with your first order at drinkag1.com/mattwalker.

In a supplement industry where trust is critical, Matt uses podcast partner Puori. Their protein powders are free from hormones, GMOs, and pesticides, with every single batch third-party tested for over 200 contaminants. For protein you can trust, save 20% at puori.com/mattwalker.

As always, if you have thoughts or feedback you’d like to share, please reach out to Matt:

Matt: Instagram @drmattwalker, X @sleepdiplomat,

YouTube: https://www.youtube.com/channel/UCA3FB1fOtY4Vd8yqLaUvolg

While we've long been told to focus on the quantity of our sleep, in today’s episode, Matt suggests a paradigm shift in our understanding of sleep health. He argues that the true cornerstone may not be how many hours we get, but the consistency of our sleep schedule. This concept of regularity - maintaining a stable bedtime and wake-time - is presented as the most impactful of four key sleep components, which also include the more familiar aspects of quantity, quality, and timing.

Matt supports this perspective with findings from a groundbreaking study that objectively tracked the sleep of nearly 90,000 people. The results are stunning: inconsistent sleep rhythms, independent of total sleep time, were linked to a significantly increased risk for a vast array of serious diseases. This research also upends the long-held belief that "too much" sleep is unhealthy. It revealed that many self-proclaimed long sleepers are actually experiencing poor, fragmented sleep, a fact hidden by less reliable self-reported data. The implication is profound: the true culprit for their associated health risks is likely not the extended time in bed, but the underlying lack of a stable, restorative sleep rhythm.

Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.

One of this week's sponsors, LMNT, offers a science-based electrolyte drink with no sugar or artificial ingredients. Try their new limited-time Lemonade Salt flavor, available May 20th! Get eight free sample packs with any order at drinklmnt.com/mattwalker. Stock up on this summer flavor while it lasts!

Another sponsor, Shopify, made launching Matt's merchandise incredibly smooth with its integrated sales system. Shopify simplifies everything from online stores to in-person sales. Start your exclusive trial and see for yourself at shopify.com/mattwalker.

Our third sponsor this week, David, is a revolutionary new protein bar developed with Dr. Peter Attia. It boasts an unbeatable ratio: 28g of protein and 0g of sugar in just 150 calories. Incredibly satiating with six amazing flavors, it’s perfect for muscle health. Visit davidprotein.com/mattwalker and buy 4 cartons to get a 5th FREE!

As always, if you have thoughts or feedback you’d like to share, please reach out:

Matt: Instagram @drmattwalker, X @sleepdiplomat,

YouTube https://www.youtube.com/@sleepdiplomatmattwalker9299