Rapamycin is a naturally occurring compound primarily used to prevent organ rejection in transplant patients. It’s also considered a promising anti-aging drug among longevity seekers.
Rapamycin has been trending on social media, where biohackers such as Dr. Peter Attia and Bryan Johnson tout it as the “gold standard” for people seeking to live a longer, healthier life.
Also known as sirolimus or Rapamune, rapamycin inhibits the activity of a protein called mTOR, which helps regulate cell growth and metabolism. Suppressing mTOR seems to weaken inflammation and accelerate autophagy, a process of purging damaged materials from cells.
Chronic inflammation is associated with diabetes, heart disease and muscle pain, so reducing it could yield several health benefits. And increasing autophagy could conceivably clear toxic proteins such as amyloid-beta and tau. Accumulation of these two proteins in the brain can lead to Alzheimer’s disease.
It’s unclear how many people are taking rapamycin for its anti-aging properties since the drug is typically taken off-label or purchased from overseas providers, the New York Times reports.
Scientists were initially tipped off to rapamycin’s anti-aging potential in 2006 when a study revealed the compound could extend the lifespan of yeast.
In 2009, other researchers found that mice who were dosed with rapamycin lived 12% longer than those who went without.
Initially believed to increase the risk of cancer, further research revealed that rapamycin actually prevents lymphoma and some types of cancer in transplant patients. Rapamycin has shown to be the most effective cancer-preventive agent in mice.
Dr. Dean Kellogg Jr., a professor of medicine and geriatrics at the University of Texas Health Science Center at San Antonio, tells the Times that while many medications were tested for their anti-aging properties as part of a National Institute on Aging research program, “rapamycin was the first one that actually made a difference in longevity and healthspan in both male and female mice.”
Data presented at the American Aging Association’s annual meeting this year showed that marmosets who were given rapamycin increased their lifespan by roughly 10%.
Whether these life-giving benefits extend to people remains unclear.
Among rapamycin supporters, the strongest link between the drug and increased vitality comes from a 2014 study that revealed that seniors who were given an mTOR inhibitor similar to rapamycin had a better immune response to the flu vaccine than those who did not take the drug.
“It really did suggest that in humans, these drugs, mTOR inhibitors, can improve something that becomes impaired with older adults,” Adam Konopka, an assistant professor of geriatrics and gerontology at the University of Wisconsin, explained to the Times.
There are downsides as well. Rapamycin users may experience mouth sores and nausea, and in some cases, insulin sensitivity and increased cholesterol have been reported.
A potentially serious concern for those who take rapamycin for longevity is that the immune-suppressing properties of the medication will increase the risk of infection or disease.
Transplant patients are given higher doses — it’s plausible that lower doses given to anti-aging enthusiasts could make them more prone to infection, particularly those with preexisting conditions.
A recent study awaiting peer review followed participants who took a weekly dose of rapamycin over the course of a year. No significant benefits or consequences were recorded, though those who took the drug reported feeling better overall.
Among those given the highest doses of rapamycin, men showed increased bone density and women had more lean muscle mass — two established defenses in the fight against aging.
Adam Salmon, a professor of molecular medicine at UT Health San Antonio, tells the Times that while obvious short-term benefits have not been reported or established, that does not mean rapamycin is ineffective.
He explains that in older animals, rapamycin appears to “prevent and preserve things” rather than reverse or rejuvenate, “So unless you’re doing a long-term human study looking at the preservation of health, you shouldn’t expect to see significant improvements.”
