Acupuncture is a therapeutic practice increasingly used to relieve chronic pain, but its clinical effects are often undervalued due to the so-called placebo effect linked to sham acupuncture techniques. In practice, many studies use simulated versions of acupuncture to compare them with real treatment, but there are several types of sham and choosing the most appropriate one isn’t straightforward, especially because there are few studies directly comparing them. A recent analysis sought to fill this gap by evaluating 45 randomized clinical trials conducted on a total of 8,287 participants with non-cancer chronic pain, comparing real acupuncture with seven different forms of sham. The main objective was to understand how pain varied, while adverse effects and the effectiveness of blinding, i.e., the ability to keep patients from knowing whether they were receiving real acupuncture, were assessed as secondary outcomes.
The results showed that the placebo effect is significant and varies depending on the type of sham used: monitored but untreated patients recorded the greatest difference compared with manual acupuncture, followed by groups in which needles were placed without penetration on the same points or on different points. Adverse events were similar across all sham types and blinding procedures proved effective in most studies. This means that even simulated acupuncture can produce real pain-relieving effects, albeit to varying degrees, and non-penetrating techniques appear to have the smallest placebo impact. However, to obtain more precise and reliable guidance on which type of sham to use as a control, more direct head-to-head comparisons between the different techniques are needed. The analysis thus emphasizes the importance of considering the placebo effect when evaluating the benefits of acupuncture and offers useful guidance for designing more rigorous clinical trials in the future.
Renato Torlaschi
Study conducted by researchers at Chengdu University in China. Wan R, Zheng Q, Zeng X, et al.Differential placebo effect of sham acupuncture for chronic pain: a network meta-analysis of randomized controlled trials. BMC Complement Med Ther. 2025 Sep 1;25(1):323
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