Misoprostol for cervical priming in non-pregnant women is not well established. 16 published randomised controlled trials have shown different cervical response and outcomes. Most of the studies have separately, but not systematically compared the effect on different patient groups, such as nulliparous women and postmenopausal women. Seven of the studies included less than 50 patients, and almost all the trials were underpowered as regards to evaluating primary outcome measures. In the study with the largest number of patients included (Thomas et al), the authors have not explained why or how they converted the primary outcome measure from "the largest-number Hegar dilator that could be inserted without resistance" to a binary variable ("Hegar > 8/Hegar < 8) after they had analysed their results - an apparent protocol violation. It appears that none of the trials have been designed and conducted in accordance with the CONSORT statement. The dosages used in the studies have varied between 200 and 1000-μg misoprostol given between 2 and 24 hours before hysteroscopy, via the oral, sublingual and vaginal routes. Trials that have used higher dosages of misoprostol, via the vaginal route, using the longest interval between administration of misoprostol and hysteroscopy have tended to show more favourable outcomes as regards to cervical priming.