I’ll direct your attention back to the multiple large-scale clinical trials cited in my previous link, which didn’t find a significant difference between sham acupuncture (where the needle does not pierce the skin) and “real” acupuncture.
“Large multicenter clinical trials conducted in Germany {Linde et al., 2005; Melchart et, 2005; Haake et al, 2007, Witt et al, 2005), and in the United States {Cherkin et al, 2009) consistently revealed that verum (or true) acupuncture and sham acupuncture treatments are no different in decreasing pain levels across multiple chronic pain disorders: migraine, tension headache, low back pain, and osteoarthritis of the knee.”
The logical conclusion is that we are looking at placebo effects. And while placebos have been associated with relief in some clinical situations, it should be noted that such effects tend to be lost over time, resulting in patients continually seeking out new placebos which seem to be temporarily effective. This can result in a lot of expenditure (money and time) for little or no gain, not to mention hazards of not seeking out evidence-based care that does have potential for significant, long-term effectiveness.
One recent comprehensive review of acupuncture covering 13 clinical trials (Madsen et al) had this to say:
“Conclusions
A small analgesic effect of acupuncture was found, which seems to lack clinical relevance and cannot be clearly distinguished from bias. Whether needling at acupuncture points, or at any site, reduces pain independently of the psychological impact of the treatment ritual is unclear.”
Those wanting, um, scientific validation of acupuncture should seek out papers by Chinese researchers/practitioners. They are notorious for never producing negative reports about acupuncture therapy.