Methylphenidate is a CNS stimulant approved for treatment of ADHD. It is generally considered well tolerated and exhibiting low dependence potential, although diversion for recreational use has been described. Provided that its effects are comparable to those of more popular drugs of abuse, such as cocaine and amphetamines, we hypothesized that it could be sold as such.

The aim of this study was:

– to describe the presence of methylphenidate from the samples handled to, and analyzed by, Spanish harm-reduction service energy control between August 2009 and August 2015;

– to determine whether it is being sold as other drugs.

All samples presented to energy control (EC) were analyzed. EC is a Spanish harm-reduction non-governmental organization that offers to users the possibility of analyzing the substances they intend to consume.

Samples in which methylphenidate was detected using Gas Chromatography–Mass Spectrometry were selected for this study.

From a total of 20062 samples, 17 contained methylphenidate (0,09%), with no clear variations among the years studied. The samples were mostly sold as amphetamine (29%), methylphenidate (23%) and ethylphenidate (18%).

Presence of Methylphenidate in the Spanish illegal drug market seems anecdotic and stable over the studied timeframe. Moreover, it was sold as substances with similar dosages, lowering potential for life-threatening intoxications. Therefore, our results suggest that diversion of methylphenidate into the drug market as adulterant is not a concerning phenomenon.