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The ban was finally lifted five years ago and patients began receiving medicines made from UK plasma again in March 2025.
As the health service scales up domestic supplies, the Express visited a processing centre in London where staff work night and day to separate whole blood donations into components.
Jan Majkowski, plasma performance and efficiency lead at NHS Blood and Transplant's (NHSBT) Colindale site, said spare plasma previously had to be incinerated.
He explained: "In the past, we could produce red cells and platelets but we couldn't use the plasma for medicines -- that was heartbreaking. Now, we don't have to incinerate them and everything is being used, all those parts of whole blood."
Donated plasma is used in two ways -- directly in hospitals, for example to stop bleeding from trauma or surgery, or to manufacture medicines such as immunoglobulins.
Currently, around 93% of plasma collected by the NHS is filtered from whole blood donations. The remaining 7% comes from direct plasma donations, which NHSBT hopes to increase in the coming years by opening new donor centres.
Alastair Hunter, NHSBT's head of plasma supply operations in plasma for medicines, said: "Plasma is liquid gold. It's as vital to patient healthcare in the UK as treatments from other elements of blood donation."
At Colindale, whole blood donations are processed on a vast manufacturing floor where staff follow meticulous steps to separate the precious components. Red cells are used to treat anaemia and blood loss, platelets can stop bleeding, and white cells can be given to patients suffering from deadly infections.
Around 1,560 pints of freshly donated blood were due to arrive on the day we visited. A whiteboard showed production targets for each component.
At one station, we watched as blood packs -- already filtered to remove white cells -- were loaded into a centrifuge and spun at 3,879 revolutions per minute. The speed separates the red blood cells from the plasma without damaging them.