A slimming pill known to have killed 33 people in the UK is being added to the list of regulated poisons in the UK, following a years-long campaign by the families of those who have died. DNP - or 2,4-Dinitrophenol - is classified as an explosive and banned for human consumption, but has been marketed on the internet as a weight-loss aid. Victims’ families hope the new restrictions will be one step closer to having the toxin banned once and for all.