The Longevity Scientist Willing to Call Out Grifters and Liars

Paul von Zielbauer
Fri, 14 Nov 2025 17:18:41 -0800
Lifestyle

The longevity supplement industry has a growing credibility problem, and most of the scientists in the best position to address it won't. They watch colleagues make claims unsupported by evidence, or start companies that sell products with misleading advertising, which degrade public trust in science. And they stay quiet.

Matt Kaeberlein doesn't stay quiet.

The University of Washington biologist and longevity medicine entrepreneur resigned from the Academy for Health and Lifespan Research in 2024 after David Sinclair, a tenured Harvard geneticist who served as the organization's president, "lied," Kaeberlein told me in a recent interview.
Updated: Fri Nov 14, 2025

The longevity supplement industry has a growing credibility problem, and most of the scientists in the best position to address it won't. They watch colleagues make claims unsupported by evidence, or start companies that sell products with misleading advertising, which degrade public trust in science. And they stay quiet.

Matt Kaeberlein doesn't stay quiet.

The University of Washington biologist and longevity medicine entrepreneur resigned from the Academy for Health and Lifespan Research in 2024 after David Sinclair, a tenured Harvard geneticist who served as the organization's president, "lied," Kaeberlein told me in a recent interview.

Sinclair had claimed in a press release that a supplement he and his brother were selling was, Kaeberlein said, "the first clinically proven supplement to reverse aging in dogs." Kaeberlein, who co-directs the Dog Aging Project, knew this wasn't imprecise language or overenthusiastic marketing.

"That to me was way, way, way over any reasonable line that anybody, let alone a Harvard tenured professor, should ever cross," Kaeberlein said.

This matters because the longevity medicine industry has become quite frothy. Venture capital pours into startups promising to slow or reverse aging. Supplements marketed as anti-aging interventions proliferate online, often promoted by scientists who lend their names and prestigious academic credentials to clinically unproven claims.

The field needs rigorous voices willing to draw clear lines between what science actually shows and what marketing departments want you to believe.

Nothing Has Reversed Aging in Humans

So when I asked Kaeberlein whether any drug, supplement or treatment has been proven to reverse aging in humans, I listened carefully, because his response matters.

"No," he told me. "And honestly, I'm offended when scientists use that phrase because it's not a scientific phrase. We have not reversed aging. We have never made an old person young again — or even an old mouse young again. It just hasn't happened."

There's reason to believe certain medications may slow aging in humans, he explained, and exceptionally strong evidence that lifestyle modifications can either slow or accelerate the biological aging process.

But reverse? That's fiction masquerading as science.

To be clear, the charlatanism problem in longevity medicine involves only a minority of scientists. Most researchers in the field present their work rigorously and appropriately. But the few who don't — particularly those with large platforms or financial stakes in supplement companies — do disproportionate damage to the field's credibility.

"People can get away with saying things that aren't true," Kaeberlein said. "And as long as you say it often and very loudly and you have a large enough podium, you're going to get a significant number of people to follow you."

The Longevity-Supplement Reality Check

Kaeberlein's own supplement regimen reflects his scientific conservatism. He measures specific deficiencies and supplements only to optimal ranges — a deliberately narrow approach.

His short list includes vitamin D, omega-3s and B vitamins if testing shows deficiency. He takes creatine (5 grams daily) paired with resistance training, which has solid evidence for modest lean mass gains. He's open to taking magnesium, he said, but says the data remains noisy.

What Kaeberlein doesn't or won't take tells a more interesting story.

The top of that list starts with NMN and NAD+ precursors, heavily promoted in longevity circles. There's just no convincing evidence that supplementing NAD is going to do anything beneficial in humans, he said, and the animal studies aren't compelling enough, either.

Resveratrol, which Sinclair spent years pushing as the supposed longevity molecule in red wine? A clinical bust that does not reverse aging in humans.

Metformin, the diabetes drug some take off-label for longevity? The concerns about its negative effects on muscle mass benefits and testosterone don't justify the potential metabolic lift for people without metabolic problems, Kaeberlein said. He prefers SGLT2 inhibitors for those who need metabolic intervention.

CoQ10, which plays a role in healthy mitochondrial function, doesn't have enough data for Kaeberlein, either.

Alpha-ketoglutarate, known as AKG, shows promise in animal studies, Kaeberlein said. (He advises a company marketing AKG). But he doesn't personally take it. Urolithin A has reasonable animal data but "disappointing" human trials, he said, that didn't measure the right outcomes.

"The best drug we've got for slowing aging in laboratory animals," Kaeberlein told me, is rapamycin. For humans, there's off-label use data and small clinical trials showing intriguing results, he said, "but I think we're not to the point where anybody should be recommending that everybody in their 50s and 60s starts taking rapamycin."

Why The Silence Persists

I asked Kaeberlein why more scientists don't challenge misleading claims from their colleagues. His answer revealed an uncomfortable truth: some field leaders embrace an "ends justifies the means" philosophy. Any attention brings money and resources into aging research. The field has expanded a lot in recent years, and some prominent figures believe the publicity benefits outweigh the credibility costs, he said.

Which crosses a line, Kaeberlein said. "I do not believe that academic scientists should be involved in selling supplements," he said, "because without exception those supplements are always sold with deceptive advertising."

His willingness to speak frankly and truthfully, even at risk of offending some of the worst offenders in longevity medicine, is refreshing and necessary.