A graduate of Stanford University - incubator of such famous blood-linked companies as Theranos - has launched a controversial start-up company, called Ambrosia, that will, for a generous fee, replace the blood of older people with that of younger donors in yet another attempt to conquer aging. Business Insider reported on the company first, while admitting there is little to no evidence that the procedure actually works.

But that hasn’t stopped Amborisa creator Jesse Karmazin, from accepting payments via PayPal for the procedure: he is charging $8,000 for one liter of young blood and $12,000 for two liters. Karmazin, who isn’t a licensed medical practitioner, told reporters last year that he had hoped to open his first clinic in New York City by the end of 2018. New York City has eluded him and instead he has opened locations in places like Los Angeles, San Francisco, Tampa and Houston.

Just like Theranos, the company also performed its own clinical trial to figure out what the effects of blood swapping would be. These results haven’t been made public, but Karmazin has called them "really positive". And despite the fact that there hasn’t been any evidence that it works, Ambrosia is allowed to continue under the FDA‘s approval of blood transfusions.

Further propelling the idea forward is the significant amount of interest it has received. After putting up its first website in September, the company reportedly got 100 inquiries (mostly from very rich people) about how to get the treatment. The company's chief operating officer at the time has since left the company in January, leaving its founder as its only employee.

As of the fall last year, the company had performed the procedure on about 150 people who ranged in age from 35 to 92. 81% of those people participated in the company's clinical trial. The trial gave patients one and a half liters of plasma from a donor between the ages of 16 and 25 and was conducted with David Wright, a physician who has his own intravenous blood therapy center in California.

Trial participants paid for their infusions and the metrics recorded in the study have not been publicly released.

"The trial was an investigational study. We saw some interesting things, and we do plan to publish that data. And we want to begin to open clinics where the treatment will be made available," the company's COO said... several months before he left.

And while there has been no evidence yet that there is any efficacy, normal blood transfusions still often save lives. When somebody has undergone surgery or been in a traumatic accident, transfusions can be one of the safest life-saving procedures available. Clinicians perform about 14.6 million transfusions per year, which equates to about 40,000 of them happening every day.

But the problem is that the science around young blood replacing old blood to fight aging simply doesn’t exist in robust form.

For instance, the results of a study that used young blood in older humans to try to counteract Alzheimer’s disease were published this month in JAMA Neurology. While the study was described as "safe, well tolerated and feasible" the authors of it were reluctant draw conclusions about potential benefits.

But that hasn't stopped Karmazin from doing so; he said in 2017: "Some patients got young blood, and others got older blood, and I was able to do some statistics on it, and the results looked really awesome. And I thought this is the kind of therapy that I'd want to be available to me."