Discovering the fountain of youth is an age-old pursuit (pun not intended). One of the latest clock-reversing experiments causing a buzz is a technique called therapeutic plasma exchange, a procedure that filters and replaces the liquid portion of your blood. A 2025 study in Aging Cell suggests the technique could lower biological age by two and a half years.
But before you start googling “plasma clinics near me,” it’s important to look past the headlines to what the study’s saying, and what it means—and doesn’t mean—about new plasma as an anti-aging elixir.
Why longevity experts care about plasma
Plasma is more than just the liquid that surrounds the red and white blood cells in your bloodstream. Although it’s mostly water, it’s also rich in proteins, metabolites, hormones, and inflammatory signals—molecules that reflect and influence what’s happening across your organ systems, Andrea Maier, MD, PhD, geriatrician and board member of the Academy for Health and Lifespan Research, tells SELF.
“It’s a transport system like DHL, a vehicle to bring things from your brain to your muscles, from kidney to lungs, and so on. So it’s fluid with lots of information,” she says.
This makes it a smart focal point for longevity studies because it can capture a wide-angle view of your body’s internal state, also sometimes called your “biological age.” By measuring changes in the levels of thousands of circulating proteins in your plasma, you can get some sense of how well you’re functioning.
What that means is you may be 40, but your biology acts more like that of a 30-year-old—or a 50-year-old. It’s not a fixed or precise measurement, but it’s helpful health information, Keenan Walker, PhD, senior investigator at the National Institute on Aging, tells SELF.
“There’s no one biological age, but people try to estimate it,” he says. “And what studies have found is that people whose biological age is older than their chronological age are at greater risk for chronic conditions, diseases, and mortality.”
About 15 years ago, researchers started exploring the connection between plasma and the aging process. This led to experiments using a process called parabiosis, a surgical technique that links together the circulatory systems of two different organisms. In studies, researchers would stitch together the systems of old mice and young mice, with the hypothesis that if you circulated younger plasma in an older organism, the older organism’s body would reap the benefits.