One of the mummies found in Southern Peru has a large number of tattoos, which have been hypothesized to be points for acupuncture.
Maria Pabst and colleagues (2010) examined a female mummy dating from 1000 C.E. and found that she was covered with tattoos. They are of two types: decorative animals and ciphers. Pabst argues that it is possible that these cipher like tattoos on the neck are acupuncture points due to their close proximity to those known today.
In order to test the hypothesis, the tattoos were examined by type. Those on the neck consisted of small circles, those on the extremities were more decorative. They investigated the tattoos using a variety of techniques: light microscopy, various electron microscopic methods and Raman spectroscopy. Analysis of the pigmented skin found that there were two different materials being used as dye: a soot based material and a plant based material. The ash based material was found in the decorative shapes. The plant based material was found on the tattoos of the neck.
Comparison of the circular neck tattoos against acupuncture charts shows that there is indeed a similarity. They would have been therapeutic, designed to relieve stress or pain in the neck and head.The argument does have merit, as those which are supposedly therapeutic tattoos are done in a different material than the other tattoos, and there is a history of tattoos as healing in this region.
This argument sets the stage for some very testable hypotheses and future research. First, the question of acupuncture sites can be addressed. The sites used for reference in the article appear to be Chinese; how would these compare to other possible acupuncture maps in non-Asian cultures? Are the acupuncture sites universal? Are there are Andean acupuncture traditions detailed in art? Second, what evidence is there that the Andean tradition of therapeutic tattooing and acupuncture actually existed in the past? Can we find evidence from art or ethnography? A quick search online revealed that they have been doing acupuncture in Peru for some time, but there was no specific history.
Future research can also address the materials used for inks. Perhaps the different types of ink were from specific plants that were meant to have medicinal purposes and that their configuration is coincidental. I would suggest looking into the materials themselves for more information on why the circular tattoos were different.
Pabst et al. 2010. Different staining substances were used in decorative and therapeutic tattoos in a 1000-year-old Peruvian mummy. In Journal of Archaeological Sciences 37(12): 3256-3262