Recent anecdotal evidence suggests that it is becoming increasingly popular among ecstasy users to attempt to negate certain side-effects or enhance the drug experience through the concomitant use of pharmaceutical drugs or supplements. This study was designed to explore the practice of deliberately using pharmaceuticals for any reason in association with ecstasy and related drug (ERD) use. A cross sectional survey was conducted with 216 adults who had used ecstasy at least once in the previous 6 months. Generally, this sample was young, well educated, and likely to be in some form of paid employment. Males were slightly overrepresented within the sample. About one quarter of the sample had deliberately taken a pharmaceutical substance for its putative effects on the euphoric effects of, or recovery from, ecstasy use. Those who reported using pharmaceuticals were significantly more likely to be male, had more 'apparent' years of use, and were more likely to have injected ERDs. As a result, there appears to be a need for harm reduction information for ecstasy users regarding the risks associated with the mixture of ERDs with pharmaceuticals and supplements. Particular attention should be paid to informing users of the potentially fatal serotonin syndrome that is likely to arise from combining serotonin-enhancing substances, such as ecstasy or SSRI and MAOI groups of antidepressants.