An acupuncturist inserts hair-thin needles under your skin. The needles usually stay in for 15 to 30 minutes. There should be little or no pain from the insertion. Expect to have several sessions. Research suggests pain relief may come from the release of endorphins, your body’s natural painkillers. Although noting a lack of rigorously controlled research about the benefits of acupuncture, the National Institutes of Health concluded in 1998 that acupuncture may help conditions that involve chronic pain, including low back pain. The Mayo Pain Clinic has used acupuncture since 1974 in some cases in which people don’t experience pain relief from medications or nerve blocks.