Party drugs are all the rage lately as more and more young people get into electronic dance music. But while most of them are turning to MDMA — also known as ecstasy, or more innocently as “molly” — some are turning to a far more dangerous drug capable of inducing the same kind of highs: mephedrone.

“Although users report that mephedrone produces similar psychoactive effects to MDMA, these two drugs produce different changes in the brain, and the adverse effects they produce, particularly when ingested with other drugs, will therefore be different,” said Professor Richard Green, a Trustee at the British Pharmacological Society, in a statement. His review, published in the British Journal of Pharmacology, compares the effects of MDMA to mephedrone, which they found could be a more addictive substance.

Both mephedrone and MDMA induce feelings of euphoria, excitement, sensory stimulation, and openness. Both are in the class of amphetamines, along with other less harmful drugs used to treat attention-deficit hyperactivity disorder, as well as more powerful drugs like methamphetamine, or meth. In the UK, mephedrone is among the most popular illegal substances used, only lagging behind marijuana, cocaine, and ecstasy.

During their review, the researchers found that mephedrone acts faster in inducing effects, quickly giving the user a high, and a stronger one at that. However, while a MDMA high lasts about three to six hours, mephedrone highs only last about an hour. This leads many people to binge on the drug, as they yearn to keep the high going. In turn, they may experience more adverse side effects, the researchers said, as well as the risk that they will become more dependent on it. This difference could make all the difference between abuse and recreational use.

“One of the key messages for medics and drug users is that even though psychostimulant drugs may initially seem similar, the differences in the way they work can be critical,” Green said in the statement. “The good news is that the effects seen in animal studies generally reflect the reported changes in humans, which gives us confidence that the warning signals on the relative risks of different drugs from these studies need to be taken seriously.”

Source: Green A, King M, Shortall S, et al. The preclinical pharmacology of mephedrone; not just MDMA by another name. British Journal of Pharmacology. 2014.