Are Tattoos Healthy? Probably Not…

Tattoos may cause permanent changes to the immune system and affect how the body responds to vaccines, according to research published in the Proceedings of the National Academy of Sciences.

An international research team found that tattoo ink travels through the lymphatic system and accumulates in lymph nodes, often within minutes of being applied. More concerning, the ink appears to remain there for life — even if the tattoo is later removed.

In experiments on mice, researchers observed chronic inflammation in lymph nodes, the death of macrophages (white blood cells critical to immune function), and altered responses to vaccinations. Notably, tattooed mice showed a weaker response to COVID-19 vaccines but a stronger response to influenza vaccines, suggesting the effects vary depending on vaccine type.

Scientists first noticed the immune effects accidentally while working with mice that had been tattooed for unrelated experiments. They then conducted focused research using standard commercial inks in black, red, and green.

The team described their work as the most extensive study to date on tattoo ink’s effect on immune response. With at least one in five people globally now having a tattoo, researchers say the findings raise significant public health questions.

“Our results are crucial in informing toxicology programs, policymakers, and the general public regarding the potential risk of the tattooing practice associated with an altered immune response,” the authors wrote.

The study adds to growing concerns about tattoo safety. Recent research published in BMC Public Health found that people with large tattoos may face three times the risk of developing lymphoma compared to those without tattoos.

Researchers are calling for further study to inform regulatory frameworks around tattoo ink safety, though they acknowledge that tattooing shows no signs of slowing down as a cultural practice.

Photo by Collins Lesulie on Unsplash