In the early 1990s, a 1000-year-old female mummy was found at Chiribaya Alta, southern Peru, with two distinct kinds of tattoos on her body. On her hands, arm and lower leg were birds, apes, reptiles and other symbols, while her neck was covered with an asymmetric pattern of twelve overlapping circles. When the tattoos were analysed using microscopy and spectroscopy, something strange was found. Most ancient tattoo inks were made of ashes and soot, and the tattoos on the mummy’s arms and legs reflected this—but the circle tattoos on her neck also contained burnt plant material. “If you use different materials, [the tattoos] have different functions,” says Maria Anna Pabst from the Medical University of Graz, Austria. While the ash and soot tattoos were decorative, the plant material suggests that the neck tattoos would have been part of a healing or strengthening ritual. The plants were most likely chosen for medicinal properties, and the circles were positioned on the mummy’s neck close to Chinese acupuncture points, so the tattooing process might have been akin to acupuncture, designed to relieve neck pain or relax the subject. This isn’t the first time we’ve suspected tattooing was used for therapeutic purposes—the oldest European mummy, Ötzi the Iceman, also has tattoos on his back and legs close to acupuncture points.