Tattoos certainly seem to be more popular than ever, but I wish more people would ask the questions you pose before getting them. I've read that more than half of those who get tattooed later regret it, only to learn that removal can be much more expensive and difficult than having one applied. In some cases, allergies to the ink used develop long after it is injected.
Of the various methods of tattoo removal, laser removal is now considered the best and safest procedure (others include excision, dermabrasion, salabrasion, and cosmetic over-tattoo). No matter which method you choose, it will be time-consuming, expensive, and may leave scars or discolorations. According to the American Academy of Dermatology, laser treatment of tattoos "may entirely remove the pigment or only bring fair results. The skin is rarely as perfect as it was prior to getting the tattoo."
Lasers have become the standard approach to tattoo removal because the risks are low and the side effects are considered minimal. Removal entails targeting the tattoo by selectively treating the pigment colors with a high-intensity laser beam. The type of laser used depends upon the pigment colors in the tattoo. The process can involve multiple treatments over a period of four to eight weeks. Costs can range from several hundred to thousands of dollars depending upon the size, type, color, and location of the tattoo and the number of treatments required.
Side effects can include discoloration or infection of the skin at the treatment site, incomplete removal of the pigment (tattoo ink) and, sometimes, a raised or thickened scar that appears months later.
You ask whether the ink remains in the body forever. We simply don't know, because there have been no systematic studies. An FDA-directed study of tattoo inks is ongoing, however. The investigators are researching the chemical composition of the different inks now in use and how they break down (metabolize) in the body. They're also looking at the short-term and long-term safety of pigments used in tattoo inks and how the body responds to the interaction of light with them (some tattoos fade in sunlight). The research team is also trying to determine whether body immune cells digest and destroy ink as they do bacteria and other foreign matter. They have found that some of the ink migrates to the lymph nodes but don't yet know the health implications of that change.
Andrew Weil, M.D.