Given research showing that the very act of communicating side effects can increase their likelihood, how can providers inform patients about side effects while upholding their oath to do no unnecessary harm? An emerging approach provides a potential solution: truthfully describe certain minor side effects as a sign the treatment is active and working in the body. This approach focuses on instilling adaptive mindsets about the meaning of side effects while still keeping patients informed. This article describes existing research suggesting that this approach can be helpful in improving experience and outcomes in treatments for pain, hypertension and allergy. Compared with control groups given a standard, empathetic message about side effects, patients who were informed that side effects are a sign treatment is working were less anxious about side effects and rated them as less threatening and intense. A longitudinal, randomised controlled trial of this approach in patients receiving oral immunotherapy for food allergies found that describing side effects as a sign treatment was working reduced the rate at which patients contacted providers with concerns about side effects and led to greater increases in a biomarker of allergic tolerance from pretreatment to post-treatment (peanut-specific blood IgG4). In unveiling this approach, this article also raises important issues regarding which treatments and symptoms this approach should be applied to. Finally, we outline questions future research should address to further understand and leverage this approach.