- Rapamycin is a prescription anti-aging drug in mice and flies.
- Matt Kaeberlein is studying rapamycin and he decided to use it to try and cure a frozen shoulder.
- While it helped him, we don’t yet know any risks or benefits of using the drug for anti-aging in humans.
A few years ago, Matt Kaeberlein, the director of the Research Institute for Healthy Aging and Longevity at the University of Washington, suffered from the agonizing pain of a frozen shoulder. He says he had trouble sleeping, felt “pissed off and depressed” and “couldn’t throw a ball” with his kid like he used to.
Kaeberlein – then 49 – had a hypothesis about what was going wrong with his body. “I started to think: This is an age-related inflammatory condition,” he told Insider. That insight led him to a possible solution: a little-known drug called rapamycin.
At work, Kaeberlein studies how the drug, an immune suppressant typically prescribed to organ transplant recipients and cancer patients, can help people age gracefully — keeping muscles pain-free, brains sharp, and even fighting off viruses.
So Kaeberlein tried rapamycin on himself, in what he admits was a loosely controlled “self-experiment” to heal his shoulder.
What he experienced over the course of about 2 ½ months of weekly use of rapamycin “made me believe” in the drug, he said. “I would say 90% range of motion was back, and the pain was probably 90% gone — and it hasn’t come back.”
Now he takes rapamycin, which costs about $1 a pill, on a cyclic schedule, dosing himself in 10- to 12-week increments every six to eight months in hopes of keeping age-related inflammation away.
Rapamycin has been shown to slow aging in flies, worms and mice
To date, Kaeberlein has tracked how more than 330 people who take rapamycin feel when they take the medication off-label to fight aging. Many say they feel great, with less stomach pain and less anxiety than their peers.
It is possible that the rapamycin has some anti-aging effects, reducing age-related inflammatory problems ranging from dementia, cancer or simple muscle pain. But we’re not sure.
In mice, rapamycin’s track record is more proven. The antifungal compound – first discovered in a clump of soil on the remote island of Rapa Nui or Easter Island – is a known life extender for flies, worms and mice. It targets a key protein in the body that regulates and promotes cellular reproduction, slowing it down and discouraging growth – much like fasting.
“Rapamycin is pretty good – in mice – at turning off age-related inflammation,” Kaeberlein told Insider.
We don’t know the risks of taking rapamycin for aging – or the best dosage for humans
While Kaeberlein’s personal experiment felt like a success, he told Insider that for now, we can’t say how beneficial or risky rapamycin might be when taken in small doses to reverse aging in our cells.
His data suggests that one of the most common side effects users experience is quite benign: mouth ulcers.
But no one has yet developed a clear protocol for using rapamycin as an anti-aging drug. Kaeberlein developed his own rapamycin routine based on what happens in lab mice.
“I don’t have a good rationale, honestly — I’m trying different things,” he said.
Other biohackers use the drug more frequently, using it once a week — simply because a 2014 Novartis study suggested it might be a better strategy than daily.
Longevity experts emphasize that anyone taking rapamycin should be under the strict supervision of a doctor. Because rapamycin can boost the immunity of the elderly against viral diseases such as flu – and it could maybe have a similar effect to COVID – it can also impair some aspects of immune function and make people more susceptible to bacterial infections.
Kaeberlein says his favorite, tried-and-true tips for aging well for now are still the ones you’ve heard many times before: eat a balanced diet, exercise, and sleep well.
“If you had to pick one thing that’s probably best,” he said, “at least for functional aging, it’s exercise.”
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