I suspect people have hoped for a way to reverse aging from the time we first learned it led to infirmity and death. This week studies from two different groups of researchers revealed that older mice experienced a reversal of many symptoms of aging when transfused with the blood of younger mice. Could it be as simple as that? Could young blood be a fountain of youth? Can you imagine the ramifications?

SF and horror writers will salivate at the possibilities. After all, Hungarian Countess Elizabeth Báthory de Ecsed is famously said to have bathed in the blood of young virgins to stay looking young (even if it’s probably not true). Then there’s the vampire mythology: beings immortal and forever young thanks to a blood diet. What would really happen if blood transfusions were the key to renewed youth?

First, it would be made illegal—because “illegal” is just another way of saying available to only the very rich. Of course the rich would want to keep this treatment to themselves. So a thriving black market would spring up (and young people with any sense wouldn’t venture outside except in large groups). And you can bet there’d be a huge shift of focus in the private health care industry. Eventually, though, more and more middle class folk would ransom their financial futures to get the rejuvenation treatment, one way or another, but would we really live longer? No, because the first thing we’d use all that regained youthful friskiness for would be to chase after new, more energetic sexual partners, and we’d be killed by boyfriends or our own jealous wives (especially if our transfused blood was still usable for somebody else with enough cash!) Those who didn’t fall into that trap would stay in the workforce long after their expected departure—they’d have to, to pay for the treatments—creating a huge unemployment crisis, especially among young people, who would finally become fed up with being robbed of both jobs and blood and would rebel in violence.

OK, perhaps I’m being a little overly cynical. Fortunately, these situations shouldn’t arise. You see, one of the research teams found that something in the young blood was reactivating dormant stem cells in the older mice to do as they should and produce fresh new muscle, blood vessels, neurons, and more. More testing narrowed it down to a protein called GDF11 that was doing the signaling. Injections of GDF11 alone produced good results in the older mice (although not as good as shared whole blood—so don’t give up on that horror story yet).

Needless to say, there’s no guarantee any of this will work the same way in humans, but the potential is certainly tantalizing enough to ensure that someone somewhere will do those tests. I guess I can be grateful that I’m past the age to be a desirable donor.