This page was reviewed under our medical and editorial policy by
Tiffany Loh, MD, Dermatologist, City of Hope | Duarte
This page was updated on June 13, 2022.
Tattoos are an ancient practice with an ever-growing popularity. Among fanatics and skeptics alike, there’s been speculation and curiosity about whether tattoos cause cancer.
In general, tattoos are thought to be safe. Yet, research into all of the inks and materials used today in modern-day tattooing isn’t totally comprehensive. In other words, they haven’t all been studied yet for their safety in humans or role in cancer. Some of the chemicals that may be found in ink, whether intentional or contaminants, are considered possible carcinogens or toxic chemicals. Additionally, having a tattoo may make it harder to detect cancer on the skin.
As tattoos have grown in popularity, new styles have developed, and new inks have been introduced into the trade. While the Food and Drug Administration monitors and issues reports on inks linked to infections, modern-day tattooing inks aren’t strictly regulated by the agency.
Modern tattooing inks typically contain water, glycerin and coloring pigments. But researchers have found that they may also include more concerning substances, such as shellac, preservatives, aromatic amines, azo dyes, hydrochloride, food coloring, ammonia and nickel, as well as other heavy metals and contaminants. Many of these substances are considered potentially toxic or carcinogenic. A 2015 study in The Lancet notes that tattoo colorants were primarily created for industrial uses, such as on top of metals and plastics, not for the skin, and that many of the colorants haven’t been tested for use in or on humans.
In 2016, researchers in Australia looked into the composition of 49 common tattoo inks. They found that chemicals in some of the inks weren’t listed on the label. About one in five of the inks, including most of the black inks, contained PAHs (polycyclic aromatic hydrocarbons), a likely carcinogen. Other concerning substances that showed up in the samples included mercury, copper and barium.
Even though inks may contain concerning ingredients, most scientific literature to date is likely to be reassuring if you have a penchant for expressing yourself through tattoos. There’s no definitive evidence to suggest an increased risk of skin cancer from tattoos. In 2012, The Lancet Oncology published a scientific review of literature on skin cancer cases among people with tattoos—the authors concluded those incidences were likely to be coincidental.
Many questions remain about the contents of modern tattoo inks. It’s not totally understood yet whether tattoos have any connection to cancer in body parts other than the skin, such as the lymph nodes, where ink particles have been found to accumulate. Research noted in the Journal of Clinical and Aesthetic Dermatology showed that tattoo ink contained nanoparticles—microscopic particles capable of traveling through the skin and into underlying blood vessels. Some evidence suggests that these nanoparticles were associated with nerve damage and toxic effects on the brain. Nanoparticles from tattoo inks—especially black ink—were found in blood vessels throughout the body.
Any risk posed by these substances isn’t necessarily eliminated when a tattoo is removed, either. Tattoo removal uses pulsed lasers to break down larger pigment particles in the skin, which may then get absorbed into the body.
In general, when proper precautions are taken, tattoos are unlikely to cause major health problems. The most common complications associated with tattoos are skin infections, especially staphylococcus aureus and streptococcus pyogenes, allergic contact dermatitis and granulomas (inflammation that causes small bumps in the skin). Viral infections, such as HIV and hepatitis from contaminated needles, are extremely rare but still possible.
To decrease the likelihood of these infections, people should visit only a licensed tattoo artist. Tattoos given by nonprofessionals, in unsterile environments or with unsterile equipment, are more likely to result in infections.