The FDA this week disputed claims that “young blood" plasma infusions can treat a variety of diseases including Alzheimer’s and dementia, which quickly had an impact on one local company that has been popular with Silicon Valley execs.

The federal agency said in a Tuesday statement that there is “no compelling clinical evidence” that getting expensive infusions of blood from young donors has any positive health effects.

Ambrosia Health — a startup based in Monterey and founded by Stanford Medical School graduate Jesse Karmazin — then decided to halt its anti-aging treatments, which started at $8,000 for a liter of blood.

On Tuesday, the FDA released a statement informing consumers and health care providers that treatments using young donors’ plasma have “not gone through a rigorous testing.”  The agency further said that people should not consider these treatments as safe or effective.

“We strongly discourage consumers from pursuing this therapy outside of clinical trials under appropriate institutional review board and regulatory oversight,” said FDA Commissioner Dr. Scott Gottlieb and Director Peter Marks.

Dr. Gottlieb and Dr. Marks issued the warning following reports that clinics in several states are offering these plasma infusions as treatment for aging, Alzheimer’s disease, dementia, heart disease, Parkinson’s disease, and post-traumatic disorder, etc.

Both FDA officials say they are seriously concerned about these claims because “there is no proven clinical benefit” of young blood plasma infusion. They said the therapy cannot “cure, mitigate, treat or prevent” the conditions mentioned above. There is “no compelling clinical evidence on its efficacy.”

Additionally, Dr. Gottlieb and Dr. Marks stressed that using any plasma products could be dangerous. Patients may experience allergic reactions, transfusion-associated circulatory overload, transfusion-related acute lung injury, or they could be exposed to infectious diseases.

Immediately after the warning, Ambrosia posted a statement on its website saying, “In compliance with the FDA announcement issued February 19, 2019, we have ceased patient treatments.”

Ambrosia began offering intravenous infusion of plasma from young donors (aged 16 to 25) as a clinical trial in 2016. Karmazin boasted at the time that the results of the trial were impressive. He claimed that the therapy helps to prevent Alzheimer’s disease and lower blood cholesterol, according to NBC News.

The startup charged its patients $8,000 for one liter of blood and $12,000 for two liters.

In 2016, billionaire Peter Thiel jumped on board touting the effectiveness of such infusions, leading to comical plot line on HBO's Silicon Valley. And in a 2017 interview with CBS SF, Dr. Karmazin said that many Silicon Valley folk as well as many Australians and Europeans were coming to receive treatment from Ambrosia.