Science for Life has over two pages on acupuncture, concluding that it is primarily a placebo-based treatment with no other benefit, but with some evidence that it was effective in the treatment of lower back pain, a view that was, at the time, supported by a Cochrane review and the UK's NICE body, which authorises medical treatments.
However, the evidence has now been through a more thorough analysis, and NICE has changed its guidance to say that acupuncture should not be offered for that remaining area, lower back pain. It seems that the original NICE guidance was subject to a number of flaws and influenced by those with a reason to want acupuncture to be recognised by the NHS.
The weight of evidence now appears to be clear that the benefits of acupuncture, like many other alternative treatments, are solely those to be gained from the placebo effect. See this post by David Colquhoun for details of the problems with the earlier assessment and the new ruling.