Romans used human feces as medicine 1,900 years ago — and used thyme to mask the smell
Dark brown flakes discovered inside a 1,900-year-old Roman glass bottle are the first direct evidence of the use of human feces for medicinal purposes, a new chemical analysis reveals. The feces were mixed with thyme to mask the smell, and the concoction may have been used to treat inflammation or infection.
“While working in the reserves of the Bergama Museum, I noticed that some glass containers contained residue” Cenker Atilaarchaeologist at Sivas Cumhuriyet University in Türkiye, told Live Science in an email. “Residue was found in seven different vessels in total, but only one yielded conclusive results.”
“When we opened the unguentarium, there was no bad smell,” Atila said. However, during its storage, “the residue inside was neglected. I noticed this and immediately started the analysis process.”
The researchers used gas chromatography and mass spectrometry (GC-MS) to identify organic compounds present in the dark brown residue they had scraped from inside the glass unguentarium. Two of the identified compounds – coprostanol and 24-ethylcoprostanol – are commonly found in the digestive tracts of animals that metabolize cholesterol.
“The consistent identification of stanols – validated fecal biomarkers – strongly suggests that the Roman “unguentarium originally contained feces,” the researchers wrote in the study. Although they could not conclusively determine the origin of the feces, the researchers noted that the ratio of coprostanol to 24-ethylcoprostanol suggests it was human.
Another major discovery in the residue was carvacrol, an aromatic organic compound found in essential oils made from certain herbs.
“In this sample, we identified human feces mixed with thyme,” Atila said. “Because we are familiar with ancient textual sources, we immediately recognized that this was a medicinal preparation used by the famous Roman physician Galen.”
In the second and third centuries, Pergamon was known as a major center of Roman medicine, thanks to the physician and anatomist Galen of Pergamonwhose ideas would dominate Western medical science for centuries.
There were several folk remedies made from feces in Roman medicine, intended to treat conditions ranging from inflammation and infection to reproductive disorders, the researchers wrote. In an exampleGalen mentions the therapeutic value of the excrement of a child who had eaten legumes, bread and wine. But since ancient doctors knew their patients would reject foul-smelling medicines, they often advocated masking them with aromatic herbs, wine, or vinegar.
“This study provides the first direct chemical evidence for the medicinal use of feces in Greco-Roman antiquity,” the researchers wrote, as well as direct evidence that the stench of feces was masked by strong-smelling herbs. “These results align closely with formulations described by Galen and other classical authors, suggesting that such remedies were materially implemented, not simply textually theorized.”
Atila, C., Demirbolat, İ. and Çelebi, R.B. (2026). Excrement, perfumes and chemical medicines, evidence of ancient therapies in a Roman unguentarium. Reports of the Journal of Archaeological Sciences, 70, 105589. https://doi.org/10.1016/j.jasrep.2026.105589
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