Rapamycin’s Pros & Cons

Rapamycin is generally heralded as a wonderdrug that (according to best evidence so far) can slow down aging, potentially adding decades to human lifespan—and yes, healthspan.

It comes from a kind of soil bacteria, which in turn comes from the island of Rapa Nui (a Chilean territory best known for its monumental moai statues), hence the name rapamycin.

Does it work?

Yes! Probably! With catches!

Like most drugs that are tested for longevity-inducing properties, research in humans is very slow. Of course for drugs in general, they must go through in vitro and in vivo animal testing first before they can progress to human randomized clinical trials, but for longevity-inducing drugs, it’s tricky to even test in humans, without waiting entire human lifetimes for the results.

Nevertheless, mouse studies are promising:

Rapamycin: An InhibiTOR of Aging Emerges From the Soil of Easter Island

(“Easter Island” is another name given to the island of Rapa Nui)

That’s not a keysmash in the middle there, it’s a reference to rapamycin’s inhibitory effect on the kinase mechanistic target of rapamycin, sometimes called the mammalian target of rapamycin, and either way generally abbreviated to “mTOR”—also known as “FK506-binding protein 12-rapamycin-associated protein 1” or “FRAP1“ to its friends, but we’re going to stick with “mTOR”.

What’s relevant about this is that mTOR regulates cell growth, cell proliferation, cell motility, cell survival, protein synthesis, autophagy, and transcription.

Don’t those words usually get associated with cancer?

They do indeed! Rapamycin and its analogs have well-demonstrated anti-cancer potential:

❝Rapamycin, the naturally occurring inhibitor of mTOR, along with a number of recently developed rapamycin analogs (rapalogs) consisting of synthetically derived compounds containing minor chemical modifications to the parent structure, inhibit the growth of cell lines derived from multiple tumor types in vitro, and tumor models in vivo.

Results from clinical trials indicate that the rapalogs may be useful for the treatment of subsets of certain types of cancer.❞

~ mTOR and cancer therapy

…and as such, gets used sometimes as an anticancer drug—especially against renal cancer. See also:

Research perspective: Cancer prevention with rapamycin

What’s the catch?

Aside from the fact that its longevity-inducing effects are not yet proven in humans, the mouse models find its longevity effects to be sex-specific, extending the life of male mice but not female ones:

Rapamycin‐mediated mouse lifespan extension: Late‐life dosage regimes with sex‐specific effects

One hypothesis about this is that it may have at least partially to do with rapamycin’s immunomodulatory effect, bearing in mind that estrogen is immune-enhancing and testosterone is immunosuppressant.

And rapamycin? That’s another catch: it is an immunosuppressant.

This goes in rapamycin’s favor for its use to avoiding rejection when it comes to some transplants (most notably including for kidneys), though the very same immunosuppressant effect is a reason it is contraindicated for certain other transplants (such as in liver or lung transplants), where it can lead to an unacceptable increase in risk of lymphoma and other malignancies:

Prescribing Information: Rapamune, Sirolimus Solution / Sirolimus Tablet

(Sirolimus is another name for rapamycin, and Rapamune is a brand name)

What does this mean for the future?

Researchers think that rapamycin may be able to extend human lifespan to a more comfortable 120–125 years, but acknowledge there’s quite a jump to get there from the current mouse studies, and given the current drawbacks of sex-specificity and immunosuppression:

Advances in anti-aging: Rapamycin shows potential to extend lifespan and improve health

Noteworthily, rapamycin has also shown promise in simultaneously staving off certain diseases associated most strongly with aging, including Alzheimer’s and cardiac disease—or even, starting earlier, to delay menopause, in turn kicking back everything else that has an uptick in risk peri- or post-menopause:

Effect of Rapamycin in Ovarian Aging (Rapamycin)

👆 an upcoming study whose results are thus not yet published, but this is to give an idea of where research is currently at. See also:

Pilot Study Evaluates Weekly Pill to Slow Ovarian Aging, Delay Menopause

Where can I try it?

Not from Amazon, that’s for sure!

It’s still tightly regulated, but you can speak with your physician, especially if you are at risk of cancer, especially if kidney cancer, about potentially being prescribed it as a preventative—they will be able to advise about safety and applicability in your personal case.

Alternatively, you can try getting your name on the list for upcoming studies, like the one above. ClinicalTrials.gov is a great place to watch out for those.

Meanwhile, take care!