The US Food and Drug Administration (FDA) is warning people against getting blood infusions, to try and slow their natural ageing process.

It is advising consumers to be cautious about establishments "offering infusions of plasma obtained from young human donors" with the claim that the plasma will treat a variety of conditions - ranging from normal aging to memory loss.

It says establishments in several different states are currently offering such a service at a cost of up to thousands of dollars per infusion.

"There is no proven clinical benefit of the infusion of plasma from young donors in the prevention of conditions such as aging or memory loss, or for the treatment of such conditions as dementia, Parkinson's disease, multiple sclerosis, Alzheimer's disease, heart disease, or post-traumatic stress disorder", the FDA says.

"The dosing of these infusions, which can involve large administered volumes, is also not guided by evidence from adequate and well controlled trials."

Be cautious about establishments in several states offering infusions of plasma from young donors as a treatment for a variety of conditions including normal aging and heart disease. https://t.co/VGxmrLuR1F pic.twitter.com/thPehOiwfj

— U.S. FDA (@US_FDA) February 19, 2019

It also says the infusion of plasma can be associated with infectious, allergic, respiratory, and cardiovascular risks.

"Even though blood products are screened for a variety of different infectious agents, there is always a residual risk that the product may contain an infectious agent," it adds.

"The infusion of plasma is occasionally associated with serious allergic reactions, including anaphylaxis, which can manifest as hives and airway obstruction".

Plasma is the liquid portion of the blood that contains clotting factors, antibodies and other proteins.

The agency is also encouraging health care professionals and consumers to report any adverse reactions resulting from the administration of plasma.