Core Takeaway: While the ultimate dream of reversing ageing remains largely confined to laboratory animals, biotech breakthroughs are already enabling us to slow certain aspects of biological decline. Truly stopping or reversing human ageing is still years—perhaps decades—away, but the scientific path is now clearer than ever.
Slowing Ageing: The Current Frontier
When it comes to extending healthy lifespan, “slowing” is the most mature field. The Interventions Testing Program (ITP) funded by the US National Institute on Aging has repeatedly shown that the drug rapamycin, originally used to prevent organ transplant rejection, can consistently extend the lifespan of mice by 15-25%, even when started in middle age. Human trials for related compounds are underway, though safety and side effect concerns remain.
Another promising avenue involves senolytics, drugs that selectively eliminate “senescent” cells—old cells that linger and damage surrounding tissue. Mayo Clinic researchers have demonstrated that clearing these cells in mice restores physical function and extends health span. Human trials with compounds like dasatinib and quercetin are ongoing, with early results suggesting improved physical performance in patients with idiopathic pulmonary fibrosis.
Meanwhile, metformin, a decades old diabetes drug, is being investigated in the TAME (Targeting Aging with Metformin) trial led by the American Federation for Aging Research. It aims to prove that ageing itself can be targeted as a medical condition, potentially delaying the onset of age-related diseases like cardiovascular disease, cancer, and cognitive decline.
Stopping Ageing: Hitting Pause
Stopping ageing entirely—pressing a biological “pause” button—is considerably harder. Some researchers argue that the hallmarks of ageing, such as epigenetic alterations, telomere attrition, and mitochondrial dysfunction, are so deeply intertwined that no single intervention can halt them all simultaneously.
The most ambitious approach comes from the field of epigenetic reprogramming. Scientists at Altos Labs, a biotech company backed by billions of dollars, are exploring whether transcription factors can reset the “epigenetic clock” to a younger state without turning cells back into embryonic stem cells. In 2020, David Sinclair’s lab at Harvard Medical School demonstrated that partial reprogramming using three “Yamanaka factors” could restore vision in old mice by repairing the optic nerve, a feat previously thought impossible. Crucially, the technique avoided tumour formation, the main risk of full reprogramming. Translating such results into safe, whole body human therapies remains a monumental challenge.
Reversing Ageing: Science Fiction Becoming Science
True reversal—restoring an old organism to genuine youth—has been achieved in animal models but not yet in humans. The Sinclair lab’s optic nerve regeneration in mice is a form of functional reversal. Other studies have shown that infusing old mice with young blood (a process called heterochronic parabiosis) can rejuvenate tissues, although human applications are unproven and controversial.
Private companies like Life Biosciences are working on reprogramming therapies, while others focus on mitochondrial rejuvenation or telomere extension. However, all these approaches carry significant risks, most notably cancer, since the same processes that rejuvenate cells can also trigger uncontrolled growth.
The Road to Clinical Reality
Even the most promising anti-ageing interventions face a daunting regulatory landscape. The US Food and Drug Administration does not recognize ageing itself as a treatable condition, meaning clinical trials must target specific diseases rather than ageing as a whole. This makes it difficult to prove that a drug extends health span in generally healthy people. The TAME trial is a historic attempt to change this paradigm.
Additionally, safety remains paramount. Drugs that slow ageing may need to be taken for decades, raising the bar for acceptable side effects. And while private investment in longevity biotech is surging—venture capital firms poured over $5 billion into the sector in 2022 alone—scientific breakthroughs do not always translate into safe, approved medicines quickly.
Conclusion
We are close to slowing certain aspects of ageing with drugs like rapamycin and senolytics, but stopping or reversing human ageing in a comprehensive, safe manner remains a distant goal. The underlying science, however, is accelerating at a breathtaking pace. The question may soon shift from “Can we slow, stop, or reverse ageing?” to “Should we, and how will society adapt when we can?” In the meantime, the most reliable anti-ageing interventions remain the ancient ones: a balanced diet, regular exercise, and avoiding smoking and excess alcohol.
