The US Food and Drug Administration is warning those who would seek infusions of young blood to ward off the afflictions of aging to not buy into the hype, according to a statement from Commissioner Scott Gottlieb yesterday (February 19). The agency cautions that plasma, the liquid part of blood, from young individuals has ?no proven clinical benefit? to treat or prevent the conditions of normal aging or associated diseases including dementia, Parkinson?s, Alzheimer?s, heart disease, or multiple sclerosis?despite what some clinics claim. The FDA statement voices concerns about the unproven treatments, but doesn?t name any companies. ?Simply put, we?re concerned that some patients are being preyed upon by unscrupulous actors touting treatments of plasma from young donors as cures and remedies,? says the statement. The FDA warns that although ?bad actors? may be charging thousands of dollars for the treatments, they come with significant risks that include allergic reactions and, more rarely, the transmission of infectious diseases. Plasma contains molecules such as signaling proteins and clotting factors but lacks red or white blood cells. After removing the plasma from young donors, it is processed, possibly filtered, and given intravenously to older customers, usually during multiple treatments, according to STAT. Following the FDA?s rebuke, a startup company named Ambrosia said it would stop its treatments. The firm was offering one liter of young blood for $8,000 and two liters for $12,000, reported Business Insider in January. Jesse Karmazin, one of the founders of Ambrosia, told Business Insider that many people out of the 30 who received transfusions from his company saw benefits such as improved appearance and muscle, according to an earlier article. Most of the research on young blood has been performed in mice and the results have been mixed. Even when the results were positive, ?nobody has actually shown over the long term how long these quote un-quote improvements persist, and we don?t know whether it?s broadly improving aspects of aging or it?s specific to certain tissues,? Matt Kaeberlein, a biologist at the University of Washington, told STAT in 2018.