||Most likely, no. The amount of heroin needed for an oral dose is more expensive than your average MDMA dose, so it is unlikely that someone would go to the effort of mixing heroin in. There have been several MDMA pill testing projects in the past few years and while pills sold as ecstasy often contain chemicals other than MDMA, heroin has only shown up once in a tested pill. You might be interested in Nicholas Saunders' short piece on the rumors of heroin-laced ecstasy from 1994.|
If you are experiencing lethargic or 'stoney' symptoms, it could be that there is some other chemical in the pill, but these effects could also simply be attributed to the normal variation in experience and the active substance is pure MDMA. Please see the EcstasyData project at:
11/23/2000: First answered by Psilo and Fire.
10/15/2007: Answer updated.