Marijuana, the most commonly used illicit drug in the United States, is taken from the leaves and flowering tops of the Cannabis sativa plant. It also comes in a more concentrated, resinous form, called hashish, and as a sticky black liquid called hash oil.gain, combining other drugs with marijuana can be extremely dangerous. Smoking a joint that has been dipped in embalming fluid or formaldehyde has effects similar to those of a joint laced with PCP-a drug that causes hallucinations, euphoria, and often times, panic or rage.