In case there were not already enough reasons to reconsider getting a tattoo, researchers say there may be one more. A team of international researchers from several European universities have determined that tattoo ink can affect the body’s immune system.
Studying the effect of tattooing on mice, the researchers found that tattoo ink accumulates in the lymph nodes and causes long-term inflammation. It also affects the immune response to two different vaccinations– those for Covid and influenza – and kills microphages, small cells in the lymph nodes which eliminate bacteria and other harmful substances.
To conduct the study, the researchers tattooed the footpads of mice and then tracked how the ink was transported from the skin of their feet to their lymph nodes.
“In this study, we characterized the immune responses to the tattoo ink accumulating in the lymph nodes (LNs). This is very relevant as tattoo ink commonly reaches and persists in this organ in most tattooed subjects, often lifelong,” the researchers stated.
Why immune system study matters
The study is important given the growing popularity of tattoos worldwide.
"Considering the unstoppable trend of tattooing in the population, our results are crucial in informing the toxicology programs, policymakers and the general public regarding the potential risk of the tattooing practice associated with an altered immune response,” the researchers stated.
According to the study’s authors, nearly one out of five individuals has at least one tattoo. And according to a 2023 survey conducted by the Pew Research Center, even more Americans – 32 percent – are tattooed.
The concern is not only because of the number of people getting tattooed, but problems arise from the tattoo ink itself, which is not soluble in bodily fluids, according to the researchers. And colored tattoo ink contains industrial pigments created for plastics, varnishes and paints, not for use in humans.
In conclusion, the researchers noted that, “This work represents the most extensive study to date regarding the effect of tattoo ink on the immune response and raises serious health concerns associated with the tattooing practice. Our work underscores the need for further research to inform public health policies and regulatory frameworks regarding the safety of tattoo inks.”
What the research means for people who already have tattoos
Because this research was conducted in animals, it does not translate directly into medical guidance for people who already have tattoos. Instead, the findings raise important questions about how tattoo ink interacts with the immune system and highlight the need for more human research, clearer safety standards for tattoo inks and informed decision-making by individuals considering tattoos.
Posted on January 13, 2026 by Jails to Jobs