OBJECTIVES: to investigate whether there is a role for direct-to-consumer (DTC) advertising in encouraging the safe, appropriate and cost-effective use of “pharmacist-only” medicines. METHODS: this study uses a discrete choice experiment (DCE) to investigate the effect of DTC advertising on consumer's preferences for cold sore treatments. A short hypothetical TV-style advertisement was created to raise consumer awareness of pharmacist only therapeutic options. Consumers were randomly allocated to one of three information conditions. The control group only received basic information and the other two groups received the advertisement. Respondents completed 16 choice sets with 3 product options and a no treatment option. Each option was described by a product brand label: antiviral tablet, antiviral cream, non-antiviral cream; and by the attributes: availability, frequency and duration of use, effectiveness, pharmacist recommendation and cost. Choices were analysed using a generalized multinomial logit model (G-MNL) and model estimates were used to predict product shares for each information condition. RESULTS: A representative sample of 1500 consumers from an online panel completed the survey. All coefficients were statistically significant. The results suggest a clear preference for lower costs, convenient and effective treatments. Responders allocated to the advertisement group were more likely to choose the branded product. Consumers commented that in addition to promoting the cold sore treatment, the advertisement confirmed the importance of seeking early treatment and the role of pharmacists in providing health care treatment. CONCLUSIONS: This paper demonstrates that the impact of DTC advertising can be estimated using DCEs. This has important policy implications, since pharmacy-only products play an important role in down scheduling medicines by allowing regulators to move a product away from prescription only, but still maintaining a level of control in dispensing.