# Photochromic Magic Ink tattoo caused no adverse events in a pilot study of 11 people

- Published: 2026-11-07 16:51 UTC
- Section: Life & Health › Medicine
- Tags: Magic Ink, photochromic tattoo ink, rewritable tattoo, disappearing tattoo, tattoo nanoparticles, intradermal implant, pilot clinical study, radiotherapy marking, Journal of Nanobiotechnology
- URL: https://realtech.media/news/rt-314d2b105ef2c15a8634b534_photochromic_magic_ink/

**In a paired pilot study, a rewritable magenta tattoo ink caused no adverse events and still switched under UV light after at least a year in human skin.**

![Photochromic Magic Ink tattoo caused no adverse events in a pilot study of 11 people](https://realtech.media/media/2026/11/de9145965f02bd19.jpg)
*Earth.com*

A pilot clinical study in the Journal of Nanobiotechnology evaluated Magic Ink, a rewritable photochromic tattoo ink, in 11 participants. The ink contains nano-engineered pigments that switch reversibly between a nearly colorless and a magenta state under visible and ultraviolet light. A permanent intradermal tattoo can therefore be visually erased and restored on demand [1]. Each participant received a Magic Ink tattoo and a matched control tattoo made with a commercial "Standard Ink" [1].

## Preclinical checks and study design

Before the human study, the authors reported third-party-verified sterility and no cytotoxicity. They confirmed the nanoparticle size and morphology and a shear-thinning rheological behavior suitable for intradermal delivery. Photochromic tests showed rapid switching kinetics and high fatigue resistance [1].

The study was paired and within-subject. Healing was assessed by clinical inspection on days 7 and 21, by participant surveys through day 21, and by photographs taken over five months [1].

## Results and limits

No adverse events were observed in either group (0/11 per group). Dermatologist assessments and participant-reported pain, redness and itch did not differ significantly between Magic Ink and Standard Ink tattoos [1]. Magic Ink tattoos stayed nearly imperceptible in the deactivated state. After at least one year in vivo they became readily visible under UV light, which the authors describe as durable retention of photoswitchable function in human skin [1].

The authors conclude that such materials can function as tolerable intradermal implants over the timescales examined. They propose further evaluation for medical uses such as marking radiotherapy treatment areas and biopsy sites in dermatology, for cosmetic uses such as permanent makeup and micropigmentation, and for body art [1].

Carson Bruns of the University of Colorado Boulder, who leads related work on multicolor inks, told Earth.com that the pilot validates one formulation, not a three-color system. In his words, only the color is rewritable: the pigment stays in the skin indefinitely, as with conventional ink. The blue, magenta and yellow inks have so far been demonstrated only in silicone and pig skin. According to Bruns, they have not passed safety testing in people.

## Sources

1. [Journal of Nanobiotechnology](https://doi.org/10.1186/s12951-026-04755-x)
2. [Earth.com](https://www.earth.com/science/engineers-created-a-new-tattoo-ink-that-disappears-and-reappears-when-you-shine-different-lights-on-it)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-314d2b105ef2c15a8634b534_photochromic_magic_ink/