Getting older and dying is so inconvenient. Eating a healthy diet and exercising is a good start in warding off death, but if you’re looking to truly up your immortality game, the answer is simple: teen blood. For a whopping $8,000, the old and the wealthy can receive a blood transfusion from a teenager. Yes, you read that right.

At Ambrosia’s clinics in San Francisco and Tampa, Florida, the wrinkled are receiving what founder Dr. Jesse Karmazin simply refers to as a “young blood treatment.” Patients are administered a transfusion of around 0.66 gallons of blood acquired from donors between the ages of 16 and 25.

“It’s like an entire set of new blood,” Karmazin tells Inverse.

As of last fall, Ambrosia had already infused 120 clients with new blood since opening its doors in 2016. Until January of this year, customers were technically only paying to participate in a clinical trial, not to receive treatment.

To call it that would require knowing what the infusions actually do. The objective of the experiment is to find out how young blood infusions change the levels of these biomarkers. Anyone who pays to take part does so in the hope that the levels will change for the better, but there are no guarantees.

What Ambrosia’s clientele is getting from teens is blood plasma — that light yellow fluid component of blood that facilitates the movement of cells and the other elements of blood throughout the circulatory system. Plasma, it seems, has become the key to unlocking our youthful glow.

Younger people produce larger amounts of healthy plasma proteins and molecules than older people, so in theory, infusions of young plasma will increase the circulatory system’s ability to carry out its normal tasks.

In order to document the results of the young blood treatment, Ambrosia’s clinics administer 150 different blood tests before the treatment, and then again after for a total of 300 tests. Yikes. The results thus far, according to Karmazin, have been surprisingly positive as blood tests of clients who have undergone the treatment show dramatic improvements in protein health. This, in turn, has improved inflammation issues as well as brain functioning and health.

See also: In Seeking Longer Lives, Why Some Want Blood of the Young

Though, with the blood treatment’s high price tag, the clinic has also received some criticism. Neuroscientist Tony Wyss-Coray, whose work with mice inspired Ambrosia’s leap of faith into the human blood game, told Science that he’s more than a little skeptical of the company’s clinical trial.

Concerns have been raised about the trial’s lack of a placebo arm, which is a necessity in rigorous clinical studies, as well as its inclusion of participants from a broad age range rather than only the elderly. To this Karmazin says that before-and-after blood tests speak for themselves, so a placebo arm would be irrelevant.

Many people don’t seem convinced. But who knows, maybe this really will be the key to eternal youth. And if it is, there will be plenty of high school kids who are gonna have very lucrative summer jobs.

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