HoldsUp

The Diary Of A CEO · 2026-04-20 · Steven Bartlett (host), Alex Tatem

Peptide Expert: What Do Peptides Actually Do? (EXPLAINED) - Dr Alex Tatem

61 research-tied claims examined: 3 contradicted 8 overstated 45 supported 5 unverified

8

Overstated

0:25:17Alex Tatemoverstatedvery low

TB-500 promotes blood flow and tissue repair at injury sites.

"And then we have the brother to that which is TB-500, this vial over here. This improves blood flow to an injured area. You could think of this as sending the soldiers, as sending the cells that are required for rebuilding that tissue matrix that was damaged by a tear or a cut, all right?" (said at 0:25:17)

TB-500 (a synthetic peptide fragment derived from the active site of thymosin beta-4, Ac-LKKTETQ) and full-length thymosin beta-4 have demonstrated pro-angiogenic, cell migration, and tissue repair properties in preclinical in vitro and animal models (such as rat tendon repair and wound healing models). However, rigorous clinical trial data evaluating the safety and efficacy of TB-500 for tissue repair or blood flow enhancement in humans are lacking, and the compound remains unapproved for clinical use in musculoskeletal injuries.

0:25:48Alex Tatemoverstatedvery low

MOTS-c improves VO2 max and exercise tolerance by upregulating energy pathways and increasing ATP production.

"We're also getting MOTS-c, and you know, some people just will call it exercise in a vial. It improves your VO2 max and your exercise tolerance, and by upregulating the energy pathway, basically making more ATP, the energy that we all use to move, it makes more of that available, all right?" (said at 0:25:48)

The claim that exogenous MOTS-c improves VO2 max, enhances exercise tolerance, and increases available ATP in humans is overstated. Preclinical animal research shows that MOTS-c administration can enhance treadmill running performance and physical capacity in young and aging mice, and modulate skeletal muscle bioenergetics via AMPK and PGC-1α pathways. However, in humans, evidence is limited to observational studies showing that endogenous MOTS-c increases in response to exercise and correlates with lower-body muscle strength, but does not correlate with maximal oxygen uptake (peak VO2). There are no clinical trials demonstrating that administering MOTS-c improves VO2 max or exercise capacity in humans.

0:26:12Alex Tatemoverstatedlow

Semax improves cognitive function.

"We're also going to get DSIP, Epithalon, and Semax, which are all peptides that affect cognitive function. So, improving thinking, like Semax is a great option for that." (said at 0:26:12)

Semax (a synthetic ACTH 4-10 analogue developed in Russia) has demonstrated neurotrophic and neuroprotective properties in animal models, functional recovery benefits in stroke patients, and altered resting-state default mode network connectivity in small human imaging studies. However, robust, high-quality randomized controlled trials confirming cognitive enhancement or improved cognitive performance in healthy humans are lacking. Describing Semax as a 'great option' for improving thinking overstates the strength, scale, and generalizability of the available human clinical evidence.

0:00:56Alex Tatemoverstatedvery low

GHK-Cu is a peptide that improves skin complexion, skin quality, hair, and nails.

"So, this is probably the most well-known peptide for skin complexion, and it improves quality of hair and nails... We have peptides that can improve skin quality like GHK-Cu." (said at 0:00:56)

GHK-Cu (glycyl-L-histidyl-L-lysine copper complex) is widely used in cosmetic formulations and has in vitro and animal evidence demonstrating stimulation of collagen synthesis, wound repair, and hair follicle enlargement, along with limited cosmetic studies reporting modest improvements in skin elasticity and fine lines. However, rigorous clinical trial evidence in humans remains sparse, and there is no established published clinical evidence demonstrating that GHK-Cu improves nail quality.

0:38:38Alex Tatemoverstatedhigh

GLP-1 receptor agonist medications slow gastric emptying, thereby reducing post-meal glucose spikes and significantly increasing insulin sensitivity.

"Because what you're doing is you are slowing gastric emptying and so you have a slower absorption of that bolus of food that you've eaten, so your glucose doesn't spike. And so, as a result, that increases insulin sensitivity significantly." (said at 0:38:38)

GLP-1 receptor agonists do slow gastric emptying and reduce postprandial glucose excursions by delaying the systemic appearance of ingested glucose. However, attributing significant increases in insulin sensitivity directly as a result of delayed gastric emptying overstates the mechanical link. While GLP-1 receptor agonists can improve peripheral insulin sensitivity, these improvements are primarily mediated by long-term weight loss and tissue-specific molecular mechanisms rather than being a direct consequence of slowed gastric emptying.

0:42:15Alex Tatemoverstatedvery low

Delta sleep-inducing peptide (DSIP) has been shown to help regulate circadian rhythms.

"So, if we look at DSIP, okay? That has been shown to be helpful with regulating your circadian rhythm." (said at 0:42:15)

Delta sleep-inducing peptide (DSIP) is a neuropeptide originally isolated in the 1970s for its ability to induce slow-wave (delta) sleep in animals. While endogenous DSIP exhibits a diurnal rhythm (peaking in the daytime and dropping at sleep onset in correlation with body temperature) and some animal experiments have observed that DSIP's physiological effects (e.g., on body temperature and blood pressure) depend on the phase of the circadian cycle, there is no robust clinical or experimental evidence demonstrating that DSIP administration regulates or resets human circadian rhythms. Claiming that DSIP has been shown to help regulate circadian rhythms overstates preliminary, descriptive physiological and animal data.

1:00:52Alex Tatemoverstatedvery low

Epithalon shows benefits in healing parts of the brain associated with regulating the circadian rhythm.

"it does show some benefits when it comes to, you know, healing parts of your brain that are, you know, associated with regulating your circadian rhythm." (said at 1:00:52)

Epithalon (epitalon), a synthetic tetrapeptide modeled on pineal gland peptide extracts, has been studied for its effects on pineal gland function and circadian endocrine secretion. Small animal models (aged rhesus monkeys and rodents) and preliminary human observations from a single research group reported that epitalon administration restored nighttime melatonin secretion and normalized the circadian rhythm of melatonin production. However, evidence demonstrating that epitalon structurally 'heals' brain regions responsible for circadian regulation (such as the suprachiasmatic nucleus or pineal gland) is lacking; the literature shows functional modulation of melatonin rhythms rather than structural tissue repair, and the findings have not been replicated in large, rigorous, independent randomized controlled trials.

1:18:55Alex Tatemoverstatedhigh

MRIs of soldiers returning from war demonstrate degeneration of the hippocampus.

"there's a part in the brain called the hippocampus that when they do MRIs on soldiers that come back from war, that'll be degenerated in them." (said at 1:18:55)

Structural magnetic resonance imaging (MRI) studies and large-scale meta-analyses demonstrate that combat exposure and combat-related posttraumatic stress disorder (PTSD) are associated with reduced hippocampal volume. A twin study in Vietnam veterans found an 11% smaller right hippocampal volume in twin brothers with combat-related PTSD compared to their unexposed twin brothers without PTSD. However, the claim overstates this finding by implying that hippocampal degeneration is a universal outcome for all soldiers returning from war; research shows that smaller hippocampal volume is specifically associated with chronic or unremitting PTSD, high perceived threat, or vulnerability to PTSD, rather than being present in all returning service members regardless of clinical status.

Unverified means no publication matching the claim was located; it does not prove the claim false. Spotted an error? See the corrections policy - disputes from the people quoted are prioritized.