Tattoo ink and cancer: what the FDA does and does not know

This page is for anyone who has a tattoo, or is thinking about one, and wonders about cancer. It sums up what the FDA says about tattoo ink and where the gaps in knowledge are.

If you look for a federal warning that tattoo ink causes cancer, you will not find one on FDA's consumer pages about tattoos. What you will find is a different set of concerns.

The agency highlights infections from contaminated tattoo inks and allergic reactions to the inks themselves. It makes one point that surprises most people. Even unopened, sealed tattoo inks can harbor bacteria and other germs that cause infections. A sealed bottle is not the same as a sterile bottle.

In FDA's separate tattoo fact sheet, reports of allergic reactions to tattoo pigments are described as rare. When they happen, though, FDA says they may be particularly troublesome, because the pigments can be hard to remove.

FDA is unusually honest about the limits of what it knows. It says there are still many questions about the long-term effects that pigments, other ingredients, and possible contaminants in tattoo inks might cause.

That sentence cuts both ways, and it is worth sitting with. It is not a warning that ink causes cancer. It is also not a clean bill of health. It is an admission that the long-term picture is simply not filled in yet.

Anyone who tells you tattoo ink is definitely safe forever, or definitely causes cancer, is going further than the agency itself will go.

Tattoo pigments sit in an odd regulatory spot. FDA's fact sheet on tattoos and permanent makeup explains it. The inks count as cosmetics. The pigments in them are color additives, which are subject to premarket approval.

But FDA says it has traditionally not used that authority here. Its reasons are other competing public health priorities, and a previous lack of evidence of safety problems tied to these pigments.

The result is what the same fact sheet describes plainly. A number of color additives are approved for use in cosmetics, but none is approved for injection into the skin. Many pigments used in tattoo inks are not approved for skin contact at all. Some are industrial grade colors suitable for printers' ink or automobile paint.

• Infection. FDA's fact sheet says unsterile tattooing equipment and needles can transmit infectious diseases. It names HIV, hepatitis, and skin infections caused by Staphylococcus aureus and other bacteria. Choose a licensed artist who uses single-use needles.
• MRI reactions. Some people have swelling or burning in the tattoo during magnetic resonance imaging. FDA says this seems to occur only rarely and apparently without lasting effects. Tell whoever is doing the scan that you have a tattoo.
• Removal. FDA says the effects of laser removal are not well understood. It also notes removal may leave permanent scarring or not remove the tattoo fully.

This is where a general question becomes personal. Treatments that lower your white blood cell count change how your body handles infection, and infection is the clearest tattoo risk that FDA names. This is a conversation to have with your oncology team before you book anything, not a decision to make alone from a web page.

Tattoos are common, and most people who have them never develop problems. Still, "no evidence of harm" is not the same phrase as "evidence of no harm," and FDA has clearly chosen the first one.

If you already have ink, nothing here says you need to worry about it. Just keep an eye on any tattoo that becomes newly raised, sore, or itchy long after it healed, and mention it if it does. If you are deciding on a new tattoo, the questions worth asking are about sterile technique and your own immune status, not about cancer, which the evidence simply has not addressed.