"There is no proven clinical benefit of infusion of plasma from young donors to cure, mitigate, treat, or prevent these conditions," FDA Commissioner Dr. Scott Gottlieb wrote.
CNN  — 

Wannabe vampires, beware: The US Food and Drug Administration warned Tuesday against using plasma infusions from young blood donors to ward off the effects of normal aging as well as other more serious conditions. Plasma, the liquid portion of the blood, contains proteins that help clot blood.

At least one company responded by ceasing patient treatments.

The infusions are promoted to treat a variety of conditions, including normal aging and memory loss as well as serious conditions such as dementia, multiple sclerosis, heart disease and post-traumatic stress disorder.

“There is no proven clinical benefit of infusion of plasma from young donors to cure, mitigate, treat, or prevent these conditions, and there are risks associated with the use of any plasma product,” FDA Commissioner Dr. Scott Gottlieb wrote in a statement Tuesday. “The reported uses of these products should not be assumed to be safe or effective,” he added, noting that the FDA “strongly” discourages consumers from using this therapy “outside of clinical trials under appropriate institutional review board and regulatory oversight.”

Gottlieb said that “a growing number of clinics” are offering plasma from young donors and similar therapies, though he did not name any in particular.

When contacted for comment, Jesse Karmazin, a graduate of the Stanford School of Medicine and founder of Ambrosia, directed CNN to the company’s website: “In compliance with the FDA announcement issued February 19, 2019, we have ceased patient treatments.”

Previously, the Monterey, California-based company’s website had offered plasma, which it referred to as a “medical treatment,” to its clients. Ambrosia, in Greek mythology, is the food or drink of the gods and confers immortality.

“Young plasma treatments are intravenous infusions of plasma from young donors, who are in the age range of 16 to 25,” Ambrosia’s website said. The company, which notes that it treats patients who are 30 or older, boasts locations in Phoenix, Los Angeles, Tampa, Omaha and Houston. It charges $8,000 for a liter of young plasma and offers 2 liters at a rate of $12,000.

“Young plasma is the result of research into the science of blood,” the company website read.

A government website lists a clinical trial sponsored by Ambrosia that included 200 people who received young donor plasma treatments. The trial, which began in 2016 and was completed last year, measured “a panel of age-associated biomarkers” before and after treatment, according to the clinical trial. In research, “biomarkers” are often used as substitute for an actual outcome, but their presence does not always equate to the clinical presence of disease.

The plasma infusion trial was not performed under the Investigational New Drug (IND) program. “When clinical trials are not conducted under an IND, it means that the FDA has not reviewed the experimental therapy to help make sure it is reasonably safe,” Gottlieb’s statement said.

Get CNN Health's weekly newsletter

Sign up here to get The Results Are In with Dr. Sanjay Gupta every Tuesday from the CNN Health team.

Gottlieb wrote, “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.”

He is concerned not only that the plasma itself may be harmful but that the “unproven purposes could also discourage patients suffering from serious or intractable illnesses from receiving safe and effective treatments that may be available to them.”