So, maybe a little rapamycin goes a long way – or at least a lot farther than we thought?

The lifespan-lengthening promise of rapamycin may be better than anyone realized.

A new study finds that the benefits of rapamycin may be achievable more safely than currently thought possible by reducing exposure to the drug.

Researchers are focused on repurposing existing, proven medications to help extend the human lifespan. Primarily used to treat cancer and prevent organ rejection in transplant patients, rapamycin is the most promising anti-aging drug available.

Animal studies have found that its off-label use can delay age-related diseases, including cognitive decline, some types of tumors, cardiovascular dysfunction and immune problems. This means it has the potential to lengthen life and its quality.

However, chronic use of rapamycin can produce potentially dangerous side effects, like insulin resistance. Other adverse reactions include weakened immune systems, anemia, and elevated cholesterol levels. Less frequently, rapamycin has caused blood clotting, strokes, and pulmonary embolisms.

But researchers from the Max Planck Institute for Biology of Aging in Cologne, Germany, have found that brief rapamycin exposure in lab animals delivers the same positive benefits as lifelong treatment – but at much reduced risk of adverse effects.

“We have found a way to circumvent the need for chronic, long-term rapamycin intake, so it could be more practical to apply in humans,” Dr. Yu-Xuan Lu, a co-author of the Max Plank research study told SciTech Daily.

The study assessed the effects of treating fruit flies briefly when they were early adults. After testing different intervals of drug administration, they found that exposing young, adult flies to rapamycin for two weeks provided the same protection against age-related illnesses in the intestine and lengthened the flies’ lives.

A study on young, adult mice found that a three-month treatment had similar protective benefits still existed when the mice reached middle age.

“These brief drug treatments in early adulthood produced just as strong protection as continuous treatment started at the same time,” Dr. Thomas Leech, co-author of the paper, told SciTech Daily. “We also found that the rapamycin treatment had the strongest and best effects when given in early life as compared to middle age. When the flies were treated with rapamycin in late life, on the other hand, it had no effects at all.”

The question to be researched now is whether a similar approach can protect humans from age-related health issues. If the life extension benefits can be achieved with lower exposure to the drug, it promises to make rapamycin an even more attractive tool in the mission to make 90 the new 50 by 2030.