How much ink really stays in your body when you get tattooed: study

Color them surprised.

In a new study, German researchers were able to track how the liquid components of tattoo ink behave in the body.

Scientists in Germany’s Federal Institute for Risk Assessment, or the BfR, were stunned to learn that only 20% of tattoo ink actually penetrates the skin — far less than previously thought. Most of the ink is expelled as the tattooed skin heals.

“The results of our study will make it possible to assess and evaluate the health risks of tattooing more accurately in the future,” said Dr. Ines Schreiver from the Dermatotoxicology Study Center at the BfR.

Professionals in Berlin tattooed 24 study participants with different commercially available tattoo inks (14 black, 10 red) spiked with three “tracer” substances that researchers followed throughout the body.

Urine and blood samples were taken before, during and after the tattoo sessions, which typically lasted 3½ hours.

Metabolites were detected in the bloodstream shortly after tattooing began. The researchers determined the substances are metabolized differently when they’re injected compared to when they are ingested.

One of the markers, in particular, was metabolized into other compounds more frequently than expected, which was attributed to certain enzymes in skin cells.

The researchers monitored the amount of tattoo ink used in each session by weighing the ink bottles before and after and examining the ink residue left behind on the dirty needles, cloths and gloves.

That’s how they were able to figure out that only around one-fifth of the color ended up in the skin.

In previous research, BfR reported that tattoo ink pigments can accumulate in lymph nodes, potentially exposing the immune system to chemicals that may be considered toxic.

Because the pigments are insoluble, they make up the solid part of the tattoo ink, so they weren’t the focus of the new study.

The findings — published last month in the journal Archives of Toxicology — come as nearly a third of American adults have a tattoo, including 22% who have more than one.

The US Food and Drug Administration considers the inks used in tattoos — including permanent makeup — to be cosmetics. That means that they do not need pre-market approval the way a drug or medical device does.

The pigments used in the inks are color additives subject to FDA approval, but the agency says it has not traditionally regulated their use.

Meanwhile, research on the health effects of tattooing continues.

Though a study last year suggested a link between tattoos and a greater chance of lymphoma, a type of blood cancer, some experts said the evidence was not convincing.