Tattooed members of society deal with all sorts of negative stereotypes; they’re considered rebellious, irresponsible, or dangerous. This tattoo prejudice is still common despite the uptick in popularity body ink has enjoyed over the last few decades, but a new study in the American Journal of Human Biology has good news for those with a few images permanently marked on their skin.

According to research from the University of Alabama, getting multiple tattoos can strengthen your immune responses and make you more capable of fighting off common infections. There is a catch, however — receiving a single tattoo can, at least for a short time, lower resistance to infections like the common cold. Dr. Christopher Lynn, UA associate professor of anthropology equated getting inked to working out when you’re out of shape — the first time hurts, but if you continue, you’ll get stronger and the soreness fades.

“After the stress response, your body returns to an equilibrium,” Lynn explained in a press release. “However, if you continue to stress your body over and over again, instead of returning to the same set point, it adjusts its internal set points and moves higher.”

To test his theory, Lynn teamed up with graduate student Johanna Dominguez and Dr. Jason DeCaro, UA associate professor of anthropology. The team approached volunteers at tattoo businesses in Leeds and Tuscaloosa and asked them about the number of tattoos they had received, and how long the procedures took. They also collected saliva samples from participants before and after their tattoo experience. After collection, the team analyzed levels of cortisol, a stress hormone known to suppress immune response, and immunoglobulin A, an antibody lining parts of our respiratory and gastrointestinal systems. Lynn described Immunoglobulin A as a front line of defense against some common pathogens, including the common cold.

Findings showed immunoglobulin A levels dropped considerably in those receiving their first tattoo, suppressed by cortisol released in response to the stress of the experience. The immunoglobulin A decrease was less among those receiving tattoos more frequently, however.

Lynn said the body sends immunological agents to the site of a new tattoo, just in case they’re needed to fight an infection. A body that undergoes multiple tattooing sessions repeatedly ups the threshold to trigger an immunological response — it gets used to the stress over time.

But before you rush out to toughen up your immune system, heed this warning from the experts: Don’t get tattooed while you’re already sick — that cortisol response could mess with your recovery.

Source: Lynn C, Dominguez J, Decaro J. Tattooing to “Toughen up”: Tattoo experience and secretory immunoglobulin A. American Journal of Human Biology. 2016.