Lemon juice, sunlight, and tattoos

In folklore, tattoos are thought to fade if rubbed with lemon juice and exposed to sunlight. The authors tested this hypothesis on shaved, tattooed rats. Tattooed controls were used. Additional substances and conditions were included in the study (tretinoin gel, liquid nitrogen, and dermabrasion). The authors conclude that India ink tattoos do not fade significantly with sunlight and lemon juice nor with the application of tretinoin gel, liquid nitrogen, or combinations thereof.