Help us: Donate
Follow us on:

Lifespan News – Rapamycin and Metformin

This episode focuses on the efficacy of this combination.

LSN Metformin RapamycinLSN Metformin Rapamycin

On this episode of Lifespan News, Ryan O’Shea discusses how rapamycin and metformin, two well-studied drugs in aging research, can be combined for synergistic effects in mice.


Rapamycin and metformin are viewed by many as the two most promising anti-aging drugs, but now scientists have found that these drugs can work hand in hand, boosting each other’s effectiveness and blocking side effects – or at least that’s what we’ve seen in mice.

Both metformin and rapamycin have been in use for decades and have decent safety profiles. However, there are reports of some notable side effects. We’re already done an episode on a possible link between metformin use and birth defects, and have discussed how it can limit exercise gains. But rapamycin also has some concerning effects of it’s own. For instance, it is known to promote hyperglycemia in some patients, probably by increasing insulin resistance and decreasing pancreatic response to glucose. Some previous studies have already shown that metformin, a diabetes drug, can alleviate this rapamycin-induced resistance, but there is high variability in the results.

When tested by the Intervention Testing Program, metformin failed to significantly increase lifespan in mice. However, in combination with rapamycin, it worked synergistically, leading to a drastic increase in median and maximal lifespan.

In this new study, the researchers put the “combination hypothesis” to the test again, using male mice of a common pre-diabetes model. The mice received either rapamycin, metformin, or a combination from 12 to 30 weeks of age.

Being pre-diabetic, these mice usually gain a lot of weight with age. Metformin treatment did not alleviate this trend, but both the rapamycin and combination treatments allowed the mice to maintain normal weight until the end of the experiment.

The mice used in this experiment are of a variety known to develop fatty liver. While metformin alone had only a modest effect, fatty liver was completely prevented by rapamycin, both alone and in combination with metformin.

Plasma insulin levels, a measurement of insulin resistance, typically rise in these mice with age. Both metformin and rapamycin were able to decrease these levels, but the combination was again superior to the single drug treatments. Somewhat paradoxically, plasma glucose levels became elevated in all treatment groups early into the experiment. In the rapamycin group, the glucose levels remained high, while in the metformin group and, especially, in the rapamycin-metformin group, the levels gradually decreased down to those observed in healthy B6 mice, which is a strain not prone to diabetes.

These mice also start exhibiting a sign of diminished insulin storage quite early in life. Rapamycin treatment exacerbated this symptom, metformin somewhat attenuated it, and the combination treatment resulted in levels similar to those of controls.

While generally considered safe, metformin is suspected to be toxic to the kidneys. In this new study, metformin treatment substantially elevated kidney inflammation levels and the albumin/creatinine ratio, a measurement of kidney damage. Rapamycin did exactly the opposite, and the combined treatment was just as good as rapamycin alone in preserving kidney function.

The researchers gathered their results in a table that illustrates the effects of the combination treatment. In every case in which one or both drugs had a beneficial effect, this effect was fully preserved. In one case, metformin enhanced rapamycin-induced insulin sensitivity despite having no effect on its own. In three cases, rapamycin-induced deleterious effects were alleviated or blocked by metformin, and in two cases rapamycin’s benefits were maintained in the combination treatment despite metformin independently working in the opposite direction.

Both rapamycin and metformin are viewed by many as promising anti-aging drugs, and despite this study’s limitations, such as using only diabetes-prone male mice, this new study demonstrates an intriguing synergy between the two molecules. Combination treatments may ultimately be the way to go.

When there’s more to share, we’ll have it for you here, so please subscribe so you don’t miss out! I’m Ryan O’Shea, and we’ll see you next time on Lifespan News.

We would like to ask you a small favor. We are a non-profit foundation, and unlike some other organizations, we have no shareholders and no products to sell you. We are committed to responsible journalism, free from commercial or political influence, that allows you to make informed decisions about your future health.

All our news and educational content is free for everyone to read, but it does mean that we rely on the help of people like you. Every contribution, no matter if it’s big or small, supports independent journalism and sustains our future. You can support us by making a donation or in other ways at no cost to you.

Lifespan News – Best Time to Exercise

This episode of Lifespan News features some rather surprising results gleaned from examining the effects of regular morning exercise on...

Lifespan News – NAD+, Fat, and Muscle

On this episode of Lifespan News, Emmett Short goes over a new study showing that nicotinamide riboside (NR) increases both...

Lifespan News – Human Brain Organoids in Rats

On this episode of Lifespan News, Emmett Short talks about how putting human neurons into rat brains can actually fulfill...

Lifespan News – NAD+ and Heart Failure

On this episode of Lifespan News, Emmett Short discusses how a compound known as Kdm8 is critical in getting NAD+...

CategoryLifespan News, News
  1. Monty Palmer
    September 4, 2022

    If the medical powers refuse to admit aging as a REAL disease are they not relegating millions to egregious horrible unnecessary suffering and torment? How can any doctor feel at all good about this?

Write a comment:


Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.