NCCIH, Acupuncture effectiveness and safety (evidence overview)

US National Center for Complementary and Integrative Health overview of the acupuncture evidence. For knee osteoarthritis, acupuncture beat no treatment and, across pooled trials, modestly beat sham, and it is conditionally recommended by rheumatology bodies. For migraine prevention it was slightly better than drugs and also slightly better than sham, though the difference from sham was small, and much of the headache benefit is attributed to non-specific effects (expectation and placebo). On safety, acupuncture is generally safe when delivered by a trained practitioner using sterile single-use needles; serious adverse events are rare and include pneumothorax and infection. A balanced authoritative summary: real but often sham-comparable effects, with a good safety profile.