On February 19, the Food and Drug Administration (FDA) released a puzzling statement cautioning consumers who were seeking blood transfusions from young people. The statement references the rising popularity of startups that claim to have found the key to unlocking the fountain of youth. Drawing on “inspiration” from research conducted on mice, these startups inject the plasma from the blood of young people between the ages of 16 and 25 into people over 35.

The companies are utilizing research from the early 2000s, when a group of Stanford researchers connected the circulatory systems of young mice to old mice in a process called parabiosis. The idea was that the young mouse’s blood would pump into the old mouse’s circulatory system, and rejuvenate the aging mouse.

Blood transfusions are not a new concept. According to the Center for Disease Control (CDC), there are more than 9.5 million blood donors in the United States and a total of 14.6 million transfusions per year. Typically, people need blood transfusions after a traumatic event in which they lose significant amounts of blood or because they have a specific illness like hemophilia or cancer. But the Stanford experiment introduced the concept of “young blood” as a potential anti-aging procedure and influenced startups to explore its use in humans.

More specifically, young blood startups are looking to exploit the science of plasma. Plasma is the liquid portion of blood that contains proteins vital to a person’s overall health. It also contains compounds whose compositional levels change as a person ages. With age, tissues become stiff and lose mass, making blood vessels rigid. This is coupled with a lower blood volume and reduced production of red blood cells. Younger blood, however, carries compounds that promote cell growth and repair.

Jesse Karmazin, the founder of the plasma transfusion startup Ambrosia, told New Scientist he believes that “whatever is in young blood is causing changes that appear to make the aging process reverse.” Karmazin has gone so far as to say that the procedure “comes pretty close” to “immortality” and that “it’s like plastic surgery from the inside out.” He also said that “[it] reverses aging. We’re pretty clear at this point. This is conclusive.” These bold assertions helped Ambrosia attract clients.

Since August 2016, Ambrosia has been transfusing people 35 years and older with young plasma. They have treated 70 people so far, all of whom paid $8,000 to be participants in Ambrosia’s study. Their results imply that the transfusions could reduce the risk of several major diseases, such as cancer and Alzheimer’s.

However, the trial did not have a placebo group, which could have skewed its results. Tufts biology professor Mitch McVey, who teaches the class Biology of Aging, says that “the gold standard for any therapeutic intervention is a double-blind clinical trial, including a placebo … I’ve read about clinical trials for plasma infusions being started, but they don’t sound controlled to me.”

A double-blind clinical trial means that both patients and researchers do not know who receives the placebo and who gets the treatment—a process Ambrosia did not follow. This double-blind trial is important, as it allows for dispassionate and unbiased results and analysis. Despite the questionable nature of the experiment, Karmazin continued to support his company’s goals; he says the next step for Ambrosia is to target the aging populations in places like New York, Los Angeles, and Florida.

Researchers who conduct experiments in this field stress that the results seen in mice are not directly applicable to humans. “It’s important to remember that what works in a mouse or [an]other animal often doesn’t work in a human,” McVey cautioned.

Along the same lines, another startup, Elevian, is urging people not to over-hype the current research. As a regenerative medicine startup, Elevian focuses their research on developing drugs to treat Alzheimer’s, coronary heart disease, and muscle dysfunction. They recognize the potential of this procedure to prevent age-related diseases and believe proteins in plasma could be a viable solution to numerous medical issues in the future. But they acknowledge that this claim requires more research and review.

Currently, there are still inconsistencies in the research being done on mice. In 2014, Elevian released two promising papers in the world-renowned journal Science, suggesting that the injection of a particular plasma compound would strengthen older mice’s muscle function, increase the brain’s blood flow, and improve memory. However, researchers at the pharmaceutical company Novartis published a conflicting report which found that high doses of the compound caused muscle atrophy in mice.

In response to Ambrosia’s young blood claims, the FDA stated that “there is no compelling evidence in its efficacy.” The FDA is also “concerned that some patients are being preyed upon by unscrupulous actors touting treatments of plasma from young donors as cures and remedies.” Since then, Ambrosia has “ceased patient treatments” in accordance with the FDA statement.

Even though this particular method garnered enough popularity to warrant a statement from the FDA, there are many other anti-aging techniques that haven’t. The medicalization of aging has a long history of fad treatments, from the vampire face-lift, to microneedling, to epidermal growth factor facials, and many more. Though injecting young plasma into an older person is a more recent experiment, the obsession with anti-aging has existed for centuries.

Human mortality and aging are inevitable, yet an industry predicated upon helping people achieve the image of youth has grown exponentially. Crow’s feet, wrinkles, and stretch marks have all been deemed unsightly signs of age, prompting a multi-billion dollar industry to emerge. This industry monetized skincare, tricking people into thinking that it is affordable—preventing the body from outwardly aging has become a capitalist order.

As the industry transitions to more invasive treatments like young blood, skin-care becomes a function of wealth. But still, the general piece of advice that magazines, blogs, and celebrities frequently dole out is to stay hydrated and avoid dairy—visible all throughout women’s magazines and websites. If you apply the right product and live a healthy lifestyle, according to this advice, you will regain the signs of youth. Ironically, this advice typically comes from the wealthy, specifically celebrities, who have access to the best treatments and products possible.

Even tycoons in Silicon Valley have become obsessed with aging. The National Academy of Medicine’s Grand Challenge in Healthy Longevity is an organization that has $25 million to give out for breakthroughs in the field. According to the New Yorker, the organization’s kickoff party in 2017 hosted Nobel prize winners, actors like Goldie Hawn, entrepreneurs, and tech billionaires like Google’s co-founder Sergey Brin. All of them gathered to discuss not only how to prevent death but how to halt aging as well. Joon Yun, a doctor and healthcare hedge fund owner, donated the first two million dollars to the challenge. He believes that if someone can “crack the code of aging,” they “can end aging forever.”

Again, this quest is nothing new. In 2013, Google launched a unit called Calico that focuses research on “the challenge of aging and associated diseases.” In 2011, a company called Unity Biotechnology was founded to “extend the human healthspan” and unburden people of the “disease of aging.” Unity Biotechnology is backed by venture capitalist Peter Thiel and Amazon’s Jeff Bezos.

While the wealthy use dermatologists, estheticians, and now research labs to delay aging, they tend to avoid talking about the costs associated with doing so. The media emphasizes lifestyle choices and glosses over the access and ability to pay for thousand dollar creams. But leaving out the connection between wealth and anti-aging has socio-cultural ramifications. Sarah Pinto, Chair of Tufts anthropology department, said that “access to therapies that are oriented toward longevity, beauty, and in some cases even health depends on disposable income, not to mention time and other aspects of access.”

And beyond access, even lifestyle changes are connected to wealth. Only certain people have access to fresh foods or even clean water. Even if Ambrosia’s young blood trials were eventually FDA approved, only those with thousands of dollars to spare will have access to their promise of renewed youthfulness.

This evasion of information can become dangerous when it starts turning to medical procedures. The young blood technique might be able to stall aging, but as the FDA warns, if not done properly, it could also lead to allergic reactions, circulatory overload, or infectious disease transmission.

Young blood is new, but anti-aging treatments are part of history. “Anti-aging fads are definitely nothing new, and I imagine that just about every civilization in the world has gone through multiple iterations of them,” Tufts history professor Alisha Rankin said. She went on to cite the fact that some alchemists claimed to have created an Elixir of Life and pointed to the historic use of hot springs to reverse the effects of aging. Amidst the constant barrage of anti-aging treatments, it is important to know how to spot the promising from the consequential.

Today, Professor McVey warns that potential fallouts of young blood transfusions “might not be apparent for years,” meaning that it will take several years of rigorous research before the FDA or any regulatory health organization approves it as a safe procedure. Rather than seeking anti-aging methods from promotional sources like women’s health sites or Buzzfeed, McVey suggests that “the best way to know if a lifespan or healthspan-promoting intervention may have real benefit is to look for studies about it in the peer-reviewed, primary biomedical literature.”

As people age, skin becomes one of the most visible sources of proof of a person’s lifestyle, and increasingly, it is also becoming evidence of their wealth. But, no matter how much young blood or trendy youth-promising product they get their hands on, the wealthy will inevitably grow old–just like the rest of us.