Open-label Placebos for Wound Healing: A Randomized Controlled Trial

Background: Open-label placebos are a novel treatment option, in which participants take placebos with full knowledge that they do not contain active medicine. Open-label placebo treatments have been shown to result in patient-reported symptom improvements, but they have not been tested on objectively measurable physiological outcomes such as wound healing. Purpose: The current study aimed to determine whether open-label placebos improved wound healing in punch biopsy wounds compared with no treatment. Methods: In a randomized controlled trial, 70 participants (mean age 27.6 ± 10.1, 58 female) were provided with information about the beneficial effects of placebos and given a 4 mm punch biopsy wound. Participants were then randomized to either an open-label placebo intervention (two placebo tablets twice a day for 10 days) or a no-treatment control group. Wounds were photographed at 7 days and 10 days to determine reepithelialization of the wound surface. Results: No significant differences were observed between the open-label placebo and control conditions in the percentage of wound area healed or for the number of participants with fully reepithelialized wounds at 7 days (placebo 7/32 wounds healed, control 10/33 wounds healed, (χ2[1, N = 65] = 0.60, p = .440, φ = 0.10) and 10 days after wounding (placebo 17/32, control 25/33 wounds healed (χ2[1, N = 65] = 3.64, p = .056, φ = 0.24). Conclusions: Open-label placebo treatment does not improve the healing rate of wounds. Open-label placebos may be beneficial for subjective patient-reported outcomes but do not influence wound healing. Australian New Zealand Clinical Trials Registration: ACTRN12616000411448.