In a new clinical study, scientists from the German Federal Institute for Risk Assessment (BfR) have traced the path and metabolism of the liquid components of tattooing agents in the body for the first time. The study, published in the journal Archives of Toxicology, shows that smaller amounts of the agents remain in the organism than previously assumed. "The results of our study will make it possible to assess and evaluate the health risks of tattooing more accurately in the future," says the head of the study, Dr. Ines Schreiver from the Dermatotoxicology Study Center at the BfR.
"The deposition of colour pigments from tattoos in the lymph nodes has been known for a long time and has also been sufficiently proven by our studies," explains Dr. Schreiver. The pigments are insoluble and therefore constitute the solid fraction of the ink. The quantity and distribution pattern of the liquid components in the body has not yet been investigated. For the study, 24 volunteers received a tattoo of their choice. The tattooing was carried out under laboratory conditions in facilities of the Charité hospital in Berlin by professional tattooists. The individual tattoo sessions lasted just under three and a half hours on average. Urine and blood samples were taken before, during and after tattooing. With the help of so-called marker substances, the BfR team was able to understand how the liquid components from the tattooing agents behave in the body and are processed by the metabolism.
The metabolites were already detectable in the first blood sample shortly after tattooing began. This also revealed that the metabolism functions differently than expected when substances are taken up through the skin during a tattooing. For example, one of the marker substances used was more frequently converted into other metabolites when compared with oral intake via food. This can be attributed to certain enzymes in the skin cells, as could be demonstrated in subsequent cell culture experiments. It can be assumed that these enzymes have a comparable effect on similar substances. The metabolites formed in this way may have different effects than metabolites formed via other uptake routes.
The study also monitored how much tattoo ink was used in each session. On the one hand, the bottles of ink were precisely weighed before and after the session. On the other hand, all the needles, cloths and gloves used were collected and the amount of ink residue adhering to them was determined. On average, only around a fifth of the colour used actually ended up in the skin. Much of it was then excreted through the wounds as they healed. The exposure data on ink deposition in the body obtained as part of the study will enable a more accurate assessment and evaluation of possible health risks from potentially hazardous chemicals in tattoo inks in the future.
Link to the study:
https://link.springer.com/article/10.1007/s00204-025-03959-8
Frequently asked questions:
https://www.bfr.bund.de/en/frequently_asked_questions_about_tattoo_inks-201880.html
Risk – The BfR podcast: "Tattoos: Body art with side effects?":
https://podcast.bfr.bund.de/2-tattoos-korperschmuck-mit-nebenwirkungen-002
About the BfR
The German Federal Institute for Risk Assessment (BfR) is a scientifically independent institution within the portfolio of the Federal Ministry of Food and Agriculture (BMEL) in Germany. The BfR advises the Federal Government and the States (‘Laender’) on questions of food, chemicals and product safety. The BfR conducts independent research on topics that are closely linked to its assessment tasks.