Tattoos: How safe are they and how do I reduce my risk of any complications?

Once a form of rebellion hidden under your sleeve, tattoos are now commonplace.

Research in 2019 found that approximately 35 per cent of the Irish population had a tattoo, and that figure is unlikely to have dropped in recent years. That would mean more than 2.5 million people on the island have a tattoo.

However, despite their growing popularity, there’s a lot scientists don’t know about how tattoos interact with the body.

When you get a tattoo, an artist uses needles to deposit ink 1-3mm into your skin. This process – and the ink itself – can cause reactions, including immune responses and bacterial infections. Some researchers are also studying whether tattoos can cause longer-term complications, such as cancer.

Chemist at New York’s Binghamton University, John Swierk, said the scientific community is not at a point to say tattoos are “definitively” safe or unsafe.

The research now being conducted, he said, is a step toward those answers.

In 2015, the Department of Health published its first draft guidelines for tattoo and body piercing parlours.

It said it was in response to the big increase in the number of people in Ireland getting tattoos. “Tattooing and body piercing is performed without incident in the vast majority of cases, but it’s important that customers understand the nature of procedures, and also the risks involved.”

Here’s what experts know about the risk of complications and how to avoid them.

What the research says

Though it’s difficult to know how many people develop problems with their tattoos – studies estimate 2 per cent to 67 per cent – some complications are more common. A study at a tattoo clinic in Denmark of a few hundred people found that 11 per cent of the complications were bacterial infections and 37 per cent were allergic reactions.

[ I made a mistake and got a tattoo. Now I’m wondering whether to get moreOpens in new window ]

Infections can occur within days of getting a tattoo. They can cause redness, drainage and fever, and they often need treatment with antibiotics, said Dr Marie Leger, a dermatologist. The cause can be contaminated equipment, skin bacteria entering the wound or the ink.

In 2012, scientists detected bacteria underlying an outbreak in an unopened ink container, suggesting contamination during manufacturing. Just a few weeks ago in the US, researchers at the Food and Drug Administration reported finding bacteria in 35 per cent of more than 200 inks they tested, even those labelled sterile.

Allergies can occur in reaction to aftercare products in the days or weeks after getting a tattoo, when skin is especially sensitive, Leger said. They can cause redness or itchiness, and topical creams may control the symptoms.

Longer-term allergies to ink can set in months or years later. They occur more frequently with red inks, Leger said, and the itchy or raised area can be confined to a certain colour: You might notice it within a red rose, for example, but not in its green leaves. In severe cases, a doctor may recommend tattoo removal, for example, by shaving off the outer layer of the skin containing the pigment.

Dr Christopher Bunick, a dermatologist, said other immune reactions can also appear as bumps in a tattoo years after getting it. The reactions can last for months or years and are typically treated with topical corticosteroids, he said.

Experts aren’t sure what sets off these responses, in part because labels on tattoo ink bottles don’t always fully describe the contents. In 2024, Swierk and his colleagues found that 83 per cent of inks they tested contained unlisted pigments or additives.

The European Union has regulations limiting certain ingredients in tattoo ink, but the United States does not, although the FDA has issued manufacturing guidance.

Do tattoos increase my risk of cancer?

Some ink ingredients, such as heavy metals, can cause health problems. Research suggests that some ink in a tattoo ends up in the lymph nodes. Scientists are beginning to study whether the chemistry of the ink, or your immune reaction to it, can lead to cancer.

In 2024, researchers, including Christel Nielsen, a public health researcher at Lund University in Sweden, found in a large study that people with tattoos may have a higher risk of lymphoma. But Nielsen said the risk of lymphoma is very low, and the increase doesn’t prove that tattoos cause cancer. Still, she said, the question warrants further investigation.

[ Tattoos are generally considered safe, but there are things you should knowOpens in new window ]

Other studies of lymphoma risk have been inconclusive, as has research on tattoos and skin cancer. On whether there’s a connection, Leger said: “I think we have to take this seriously for sure, but we still don’t really know yet.”

How to reduce your overall risk

If you’re getting a tattoo, Bunick said, it’s important to make sure beforehand that there are no open sores in the area and to keep the tattoo clean and protected from the sun afterwards. Leger recommended avoiding red pigments if you’re worried about allergies. You should see a doctor if you notice signs of infection or changes in your skin’s texture months or years after getting a tattoo, she said.

Working with an experienced tattooist can also help. “Tattoo artists are serious professionals, and many of the known definite risks around infections and even allergies can be mitigated by working with a good artist,” Swierk said.

Ultimately, the decision to get a tattoo comes down to personal choice. “There are plenty of good reasons to get a tattoo, and people have to weigh that there is a degree of uncertainty there,” Swierk said. “But that doesn’t mean that they shouldn’t get a tattoo.” – This article originally appeared in The New York Times