Recently, the US Food and Drug Administration made a somewhat strange request: please don’t buy transfusions of young blood plasma to improve your health. The announcement is a conclusion of sorts to years-long hype over the tantalizing possibility that the fountain of youth can be found in the bodies of other people.

To find out why that’s not exactly the case, we spoke to Irina Conboy and Michael Conboy, a husband-and-wife research team at UC Berkeley. Back in 2005, the Conboys published one of the landmark papers that kicked off this hype — but the research wasn’t looking at blood transfusions and it wasn’t exactly done in humans. That didn’t stop companies like Ambrosia Health from promising that a couple liters of blood (at $8,000 a pop) would reverse aging, even though the procedure was more likely to put people in danger.

The latest Verge Science video covers this odd story, which is about real science, overgeneralized results, lots of high hopes, and people trying to make a quick buck.