The name suggests a drug that offers the same high as marijuana. These products known as "synthetic marijuana", are chemical compounds sprayed onto dried plants, then smoked.

Although these chemical compounds share a moniker with the well-known botanical, they're not the same thing. The "highs" they produce can be wildly unpredictable, and they've been associated with thousands of emergency-room visits each year, plus an alarming uptick in calls to poison-control centers. They can cause vomiting, seizures, kidney damage, and violent and suicidal behavior, and they're suspected of causing a number of deaths in the past several years.

One problem is that compounds can be sprayed unevenly over the plant material, creating deadly "hot spots" where too much chemical is smoked at once. Another problem is that manufacturers change the chemical compositions frequently to evade legal prosecution. In 2015 a bill was reintroduced in the Senate that would enable prosecutors to pursue synthetic-marijuana dealers bases on marketing and product-label claims. In the meantime, the best hope of curbing use is to spread this message around:

Synthetic marijuana has no medical value; it won't get you high in the same way as regular marijuana. In fact, it could kill you.

This article was originally published in the June 2016 issue of Consumer Reports magazine.