Plastic bottles have been turned into a Parkinson’s drug using bacteria, in what researchers say is a first for a neurological disease.
Scientists at the University of Edinburgh engineered E. coli bacteria to turn a plastic widely used in food and drink packaging, polyethylene terephthalate, or PET, into L-DOPA, also called levodopa, which is used to treat Parkinson’s.
Levodopa helps the brain produce dopamine, a chemical involved in movement, to treat symptoms such as tremors, stiffness and slowness.
Traditional methods of making pharmaceuticals rely on fossil fuels, so reusing plastic is thought to be more sustainable.
Liz Fletcher, deputy chief executive at the Industrial Biotechnology Innovation Centre, said: “Turning plastic bottles into a Parkinson’s drug isn’t just a creative recycling idea, it’s a way of redesigning processes that work with nature to deliver real-world benefits.
“By demonstrating that a harmful material can be converted into something that improves human health, the team is proving that sustainable, high-value applications of biology are both practical and effective.”
For the study, researchers broke down PET waste into chemical building blocks of terephthalic acid. Molecules of terephthalic acid were then transformed into L-DOPA by the engineered bacteria through a series of biological reactions.
About 50m tonnes of PET waste is produced every year, so using this waste to produce a drug is more sustainable than traditional methods of making pharmaceuticals and prevents plastic from ending up in landfill.
But this is not the first time plastic has been repurposed and transformed into a drug. Chemists at the University of Edinburgh also used E. coli to make paracetamol in June 2025.
Like L-DOPA, paracetamol is also currently made using oil, and further research is needed to produce painkillers in this way at commercial levels.
Researchers said these findings could mean more products are created by recycling plastic. In addition to pharmaceuticals, flavourings, fragrances, cosmetics and industrial chemicals could be made in this way.
Stephen Wallace, of the University of Edinburgh’s school of biological sciences, who led the study, said: “This feels like just the beginning. If we can create medicines for neurological disease from a waste plastic bottle, it’s exciting to imagine what else this technology could achieve.
“Plastic waste is often seen as an environmental problem, but it also represents a vast, untapped source of carbon.
“By engineering biology to transform plastic into an essential medicine, we show how waste materials can be reimagined as valuable resources that support human health.”
