Sage tea thujone and its metabolites in human urine
What it found
After drinking sage tea, seven people quickly excreted two breakdown products of thujone in their urine, and only tiny amounts of thujone itself.
The third expected breakdown product was not found.
What they found
Studies in people
Thujone in urine
Only a tiny amount of unchanged α-thujone was found in urine, with a maximum of 94.3 ng/L. It was mostly gone within 4.5 hours.
Breakdown products found
The breakdown products 4-hydroxythujone and 7-hydroxythujone were found in the urine of all volunteers. They were excreted quickly, mostly within 7 to 8 hours.
Missing breakdown product
The breakdown product 2-hydroxythujone was not detected in any urine sample.
How much was recovered
Over 24 hours, the total amount of α-thujone and its breakdown products recovered in urine was 15.8 to 38.8 µg. This was only 3.3 to 7.1% of the amount consumed.
Conjugation in the body
The breakdown products were found both free and attached to glucuronic acid or sulfate. For two samples, at least 66% of 4-hydroxythujone and 55% of 7-hydroxythujone were in the attached form.
What the authors conclude
“The small amount of detected α-thujone, and the fast excretion of the less toxic hydroxythujones, showed the effective detoxification in humans.”
Also in their conclusions
- They say the fast metabolism means a potentially toxic substance stays only a short time in the body.
- They state that the small amount of α-thujone detected and the fast excretion of the less toxic hydroxythujones show effective detoxification in humans.
- They note that despite similarities between the seven people, there were individual differences in metabolism, and that 2-hydroxythujone appears negligible in humans.
How it was done
Thujone is a compound in sage and other herbs that has been linked to nerve effects in animal studies. The authors wanted to see how the human body handles thujone from a normal sage tea, because most previous work had been done in animals or in lab dishes.
Seven healthy volunteers drank 900 mL of sage tea containing 575 µg of α-thujone. Their urine was collected over 24 hours and analysed for α-thujone and three breakdown products (2-hydroxythujone, 4-hydroxythujone, and 7-hydroxythujone).
What it can’t tell you
- This study had only seven people, so the results may not apply to everyone.
- The study measured what was excreted in urine over 24 hours, so it cannot show what happened to the rest of the thujone that was not recovered.
Who paid
- Conflicts
- The authors declare no conflict of interest.
- Authors work at
- Technical University of Munich, Germany; University of Basel BPR 1096, Switzerland; the University of Queensland, Australia
The paper
- Title
- Quantification of α-Thujone and Its Metabolites in Human Urine after Consumption of a Sage Infusion Using Stable Isotope Dilution Assays
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Thamm I, Tiefenbacher K, Rychlik M (2018). Quantification of α-Thujone and Its Metabolites in Human Urine after Consumption of a Sage Infusion Using Stable Isotope Dilution Assays. Toxins. doi:10.3390/toxins10120511Free full textPubMed 30513900DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error