An anonymous reader writes: A startup called Ambrosia is charging about $8,000 a pop for blood transfusions from people under 25, Jesse Karmazin said at Code Conference. Ambrosia, which buys its blood from blood banks, now has about 100 paying customers. Some are Silicon Valley technologists, like Thiel, though Karmazin stressed that tech types aren't Ambrosia's only clients, and that anyone over 35 is eligible for its transfusions. Karmazin was inspired to found Ambrosia after seeing studies researchers had done involving sewing mice together with their veins conjoined. Some aspects of aging, one 2013 study found, could be reversed when older mice get blood from younger ones, but other researchers haven't been able to replicate these results, and the benefits of parabiosis in humans remains unclear. "I think the animal and retrospective data is compelling, and I want this treatment to be available to people," Karmazin told the MIT Technology Review.