From the Hungarian "blood countess" who bathed in virgin blood to retain her youth to the lurid urban legend of Keith Richards "replacing" his blood to cure addiction, tales of using the blood of the healthy to cure the sick have long been a staple of popular culture. 

One Silicon Valley startup is taking the stories into the realm of reality, offering transfusions of young people's blood for the low price of $8,000.

The company, Ambrosia, is prohibited by FDA rules from making specific health claims about what getting a transfusion of youthful blood can do for you. But in a presentation at a conference in May 2017, Ambrosia founder Jesse Karmazin, said that he hopes to create a body of research into whether any disease or age-related disorder can be abated with plasma from younger, healthier people.

Karmazin, a Stanford-educated (though non-practicing) physician, has embarked on a clinical trial "to evaluate the beneficial effects of infusions of plasma from young donors using blood biomarkers," according to documents filed with the government's clinical trial website. He claims 100 people have signed up, and he's hoping to get 600 people total, creating what he thinks will be a large enough sample size to see if the transfusions can ease or eliminate the effects of "anemia, neutropenia, thrombocytopenia, obesity, diabetes, high cholesterol, elevated risk of cancer, atherosclerosis, dementia, and cataracts."

On its website, Ambrosia justifies the science behind the clinical trial with links to several previous trials using plasma from young donors in both humans and mice. In particular, Kazmarin has cited a 2014 study where old mice were injected with the plasma of young mice, and seemed to have an improvement in their memory and ability to learn. 

But researchers asked about the efficacy of tranfusing older people with young blood are extremely skeptical of the both the science and ethics behind what the company is doing. 

The leader of the 2014 study, Stanford researcher Tony Wyss-Coray, told Science Magazine in 2016 that there was no evidence the transfusion treatment would be beneficial, and that Ambrosia was "basically abusing people's trust and the public excitement around this."

Another researcher quoted by Science Magazine, University of Washington aging biologist Matt Kaeberlein, said the trails design, including the lack of a placebo, will render it useless. "I don’t see how it will be in any way informative or convincing,” he said.

Kazmarin has claimed that because patients, who must be over 35, are paying to participate in the trial, giving them a placebo (ie, blood that wasn't from young people) would be inappropriate. But this lack of a control group eliminates a basic tenet of clinical trials to avoid placebo effect. That's part of why researchers say Ambrosia isn't conducting a scientific study, but a marketing campaign trying to entice old rich people to live off the blood of youth. 

"There are a lot of patient-funded trials run by companies that use the trials as a way to sell products that wouldn’t be marketable because they’d have to be regulated by the FDA,” Jonathan Kimmelman, a bioethicist at McGill University in Montreal, told the MIT Technology Review in January.

Researchers have other issues with the trial besides its efficacy. Ambrosia buys the blood it uses from blood banks, and the young and healthy donors under age 25 who don't know their blood is being used this way, and aren't being compensated beyond anything they might get for making the initial donation. There is also inherent risk to blood transfusion, which can include "hives, lung injury, or even deadly infection" according to MIT Technology Review.

While Ambrosia's technology doesn't have the backing of scientists or researchers, it has caught the eye of at least one prominent Silicon Valley investor: PayPal co-found Peter Thiel. Already interested in life-extension technology, Thiel told Inc that the method Ambrosia was exploring was "very interesting." Kazmarin has also claimed that Thiel's company reached out to him to find out more—though he didn't confirm Thiel or anyone else is either investing in or using the transfusions.

Despite the criticism over his methodology and thesis, Kazmarin is hoping to have his initial data compiled by June 2018. The company did not respond to a request for comment from ATTN:.