PMA, or paramethoxyamphetamine, is the reason to avoid dirty ecstasy pills. A weakly psychoactive amphetamine, PMA can cause a number of adverse physical reactions at low doses. It might even kill you.
“It appears that PMA elevates body temperatures dramatically; the cause of this property is suspected to be related to its ability to inhibit MAO-A and at the same time releasing large amounts of serotonin, effectively causing serotonin syndrome. Amphetamines, especially serotonergic analogues such as MDMA, are strongly contraindicated to take with MAOIs. Many amphetamines and adrenergic compounds raise body temperatures; whereas some tend to produce more euphoric activity, or peripheral vasoconstriction, or tend to favor one effect over another, it appears that PMA activates the hypothalamus much more strongly than MDMA and other drugs like ephedrine, thereby causing rapid increases in body temperature (which is the major cause of death in PMA mortalities). Many people taking PMA try to get rid of the heat by taking off their clothes, taking cold showers or wrapping themselves in wet towels, and even sometimes by shaving off their hair.”
Be careful out there.