Start-up injects old people with the blood of the young

We are in serious bad sci-fi movie territory here.
Ambrosia is a start-up offering 'young blood' to people who are not 'young.' This blood is supposed to make you all awesome again! Like before your blood got all old! Only problem being the scientists who conducted the study say it is dangerous.

Apparently, folks are lining up to get injected with the blood of the young.

Business Insider:

Does young blood hold the keys to a long and healthy life? Startup founder and and Stanford Medical graduate Jesse Karmazin believes it might, so he launched a startup called Ambrosia Medical that fills older people's veins with fresh blood from young donors.

But researchers who study the procedure say it poses major risks for patients, including an elevated risk of developing several serious conditions later in life, such as graft-versus-host disease, which can occur when transfused blood cells attack the patient's own cells, and transfusion-associated lung injury.

Irina and Michael Conboy, two University of California at Berkeley researchers who've published research on young blood transfusions in mice, called Ambrosia's plans 'dangerous.'

'They quite likely could inflict bodily harm,' Irina Conboy told Business Insider.

The Conboys' concern stems from an awareness of what happens in the body when it receives foreign blood from a donor.

'It is well known in the medical community — and this is also the reason we don't do transfusions frequently — that in 50% of patients there are very bad side effects. You are being infused with somebody else's blood and it doesn't match,' Conboy said. 'That unleashes a strong immune reaction.'

Karmazin told Business Insider that the Conboys' statements 'are not supported by data or clinical experience.'