There appears to be a private clinic where people can pay $8,000 so their veins could be pumped with blood plasma from teenagers and young adults. This is courtesy of Jesse Karmazin, the entrepreneur who, with his startup Ambrosia, wants to utilize the potential of "young blood."

According to Business Insider, Karmazin says that within a month, most participants will "see improvements" from the one-time infusion of a two-liter bagful of plasma, which is blood with the blood cells removed.

Clinicians say Karmazin's trial appears to be "so poorly designed" it cannot hope to provide evidence about the effects of the transfusions. Some say the pay-to-participate study, with the potential to collect up to $4.8 million from as many as 600 participants, may even be a scam.

What's certain is that it's based on some intriguing science. Karmazin, a 32-year-old Princeton graduate, says he's inspired by studies on mice that researchers had "sewn" together, with their veins conjoined in a procedure called parabiosis.

Such studies offered clues that certain hallmarks of aging can be reversed or even be accelerated when old mice get blood from young ones. For instance, an influential 2013 paper in the journal Cell showed that a particular component in young blood, GDF11, increased muscle strength. However, others can't replicate the findings.

Meanwhile, there is some potential in young blood to treat diseases. For instance, one test sponsored by the University of California, San Francisco, is examining the effects of transfusions in patients with a degenerative disorder called progressive supranuclear palsy.

In 2014, Stanford University researchers demonstrated that old mice had increased neuron growth and improved memory after about 10 infusions of blood from young mice. However, like other researchers and bioethicists, the Ambrosia trial may be funded by participants and not investors.

Karmazin shares none of this hesitancy. He said the animal and retrospective data is compelling in itself and he wants the treatment to be available to other people. Karmazin also said his participants are seeing miraculous results. One of his 25 participants, a patients with chronic fatigue syndrome, "feels healthy for the first time" and "looks younger."

According to Technology Review, the formal goal of the study is to measure the effect of young plasma on about 100 biomarkers. Before the infusion, and one month after, all participants will have their blood analyzed for biomarkers that include everything from hemoglobin to leptin. 

However, Irina Conboy, a professor at University of California, Berkeley, thinks the biomarker results will be meaningless, as there's no control arm with patients who don't get plasma. She also explained that biomarkers change for a lot of reasons as well. There's no evidence yet to suggest that an infusion of plasma from young to old animals reverses aging.