Is Tattooing an Injection? Evaluating the Mechanics of Ink Placement

Guidance recently released by the Food and Drug Administration (FDA) regarding tattoo inks describes tattooing as an injection process, but is injection the correct terminology to use when describing tattooing? This perspective aims to provide a brief overview of the core mechanics and science behind injection and tattoo processes, as well as emphasize the importance of using the correct terminology when referencing tattoos and the act of tattooing moving forward. STATEMENT OF SIGNIFICANCE: Due to a change in the FDA regulatory framework around cosmetics in December 2022, for the first time the FDA is in the process of actively regulating tattoo inks. Central to how tattoos will be regulated is whether tattoos and tattooing should be considered an injectable process. If tattoos are injectables, then tattoo inks would be considered within a medical device framework leading to a radical alteration tattoo industry in the US and globally. This perspective surveys the literature to understand what it means for something to be "injected" and then compares that to the state-of-the-art understanding about how tattoos are deposited in the skin. Based on this analysis, it is clear that tattooing should not be described as an injection process.