I don't have them handy but there are at least two studies that show that cAMP is elevated in the tissue surrounding a needle, suggesting that ATP is being used in the process of tissue metabolism and repair. The mechanism is still not completely understood, but there are enough clues to suggest that physiology is at play, not just energy channels. There are also many studies that show efficacy for specific conditions. Enough that I, as a diehard skeptic, am amenable to the use of needling. Because I do not intend to practice it, I am not hoarding printouts of the studies regarding it.