Spores on the conidiophores of the fungus Penicillium notatum. Dr. Fred Hossler/Visuals Unlimited/Corbis

We used to recycle patient urine - to get penicillin.

Why? Because in 1940, during a World War, it was an intensive process. Getting usable penicillin from Penicillium notatum mold was no easy feat, says PBS: “In spite of efforts to increase the yield from the mold cultures, it took 2,000 liters of mold culture fluid to obtain enough pure penicillin to treat a single case of sepsis in a person.”

But not all of the penicillin given to a patient is actually broken down. Most of the penicillin passes through the body unchanged, which is one reason why overuse of antibiotics, which can then end up in a municipal water supply, is cautioned against.

Science met practicality and so researchers came up with a novel way to get the valuable penicillin they needed: extracting and isolating it from patients' urine.

That's pee recycling even Frank Herbert didn't think of.

We Used to Recycle Drugs From Patients' Urine By Colin Schultz, smithsonian.com