Dark-brown flakes discovered inside a 1,900-year-old Roman glass vial are the first direct evidence for 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 storage rooms of the Bergama Museum, I noticed that some glass vessels contained residues,” Cenker Atila, an archaeologist at Sivas Cumhuriyet University in Turkey, told Live Science in an email. “Residues were found in a total of seven different vessels, but only one yielded conclusive results.”
“When we opened the unguentarium, there was no bad smell,” Atila said. During its stay in storage, however, “the residue inside it was overlooked. I noticed it and immediately initiated the analysis process.”
The researchers used gas chromatography-mass spectrometry (GC-MS) to identify the organic compounds in the dark-brown residue they had scraped from inside the glass unguentarium. Two of the identified compounds — coprostanol and 24-ethylcoprostanol — are typically 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 fecal material,” 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 present in essential oils made from certain herbs.
“In this sample, we identified human feces mixed with thyme,” Atila said. “Because we are well-acquainted with ancient textual sources, we immediately recognized this as a medicinal preparation used by the famous Roman physician Galen.”
During the second and third centuries, Pergamon was known as a major center for Roman medicine, thanks to the physician and anatomist Galen of Pergamon, whose ideas would come to dominate Western medical science for centuries.
There were several popular feces-based remedies in Roman medicine that were meant to treat conditions ranging from inflammation and infection to reproductive disorders, the researchers wrote. In one example, Galen mentioned the therapeutic value of the feces of a child who had eaten legumes, bread and wine. But because ancient physicians knew their patients would reject foul-smelling medicines, they often advocated for masking them with aromatic herbs, wine or vinegar.
“This study provides the first direct chemical evidence for the medicinal use of fecal matter in Greco-Roman antiquity,” the researchers wrote, as well as direct evidence that the stench of the excrement was masked with strong-smelling herbs. “These findings closely align with formulations described by Galen and other classical authors, suggesting that such remedies were materially enacted, not merely textually theorized.”
Atila, C., Demirbolat, İ., & Çelebi, R. B. (2026). Feces, fragrance and medicine chemical evidence of ancient therapeutics in a Roman unguentarium. Journal of Archaeological Science Reports, 70, 105589. https://doi.org/10.1016/j.jasrep.2026.105589
