An article setting out the risks of a lethal synthetic drug that has already lead to thousands of deaths in America, and now in the UK. 

These are two lethal man-made opioids – fentanyl, a painkiller 100 times more potent than morphine; and carfentanyl, an elephant tranquilliser 10,000 times stronger than street heroin. Only a few grains of carfentanyl – 0.00002g – can be fatal.