Ancient Romans really used poop as medicine—and chemistry proved it
A recent Phys.org article “Poop as medicine? A Roman vial's chemistry backs up ancient medical texts” reports that scientists just found the first real evidence that ancient Romans actually used human poop as medicine. Old medical textbooks have referenced this practice before, but nobody had any direct physical evidence until now. Dr. İlker Demirbolat, a professor at Cumhuriyet University, got their hands on an ancient Roman glass vial called an unguentarium, estimated to be around 1,800 years old, that managed to preserve a small amount of dried residue inside.
They analyzed the residue using Gas Chromatography Mass Spectrometry, or GC-MS for short. Basically, it’s a technique that separates substances into their chemical components for identification. What did they find? Molecules called coprostanol and 24-ethylcoprostanol. These are strongly indicative of digested fecal matter, and the ratio of chemicals pointed to a human source. There was also carvacrol, a chemical from thyme oil, which was likely used to help cover up the smell.
Without analytical chemistry, this whole discovery wouldn’t even be possible. GC-MS lets scientists pick out chemical “fingerprints” from ancient residues, nearly 2000 years old. Thanks to these characterization techniques, we know ancient doctors like Galen weren’t just making up weird poop treatments, they actually did them.
On a larger scale, the researchers think the Romans prepared this fecal medicine for therapeutic treatment and thyme could have been added to keep the patient from gagging or refusing the treatment due to the smell. It sounds gross, and rightly so, but it lines up with something we do today: fecal microbiota transplants or FMT. Doctors actually use these to treat serious gut infections. So, as much as we cringe, the core idea—using gut bacteria to heal—still matters.
If I’m honest, I never thought I’d be reading about ancient bottled poop in a conversation about chemistry, but here we are. It’s really gross, but kind of amazing that chemistry can still pull secrets out of an ancient bottle after almost 2,000 years. And the weirdest part? Modern medicine is just a more refined version of the same principle.
Paul Arnold, Phys.org (Feb 4, 2026)
https://phys.org/news/2026-02-poop-medicine-roman-vial-chemistry.html
