A grieving mother in England is sending a warning to others, in hopes of preventing another death like that of her daughter, 21-year-old Eloise Parry.

Parry died after doctors were unable to reverse the devastating effects of an overdose of dinitrophenol, known and sold online as DNP, a weight loss pill with a history of deadly side effects.

DNP is a toxic chemical originally used in World War I to make explosives. It became a popular weight loss drug, touted for its ability to burn off pounds quickly. The United Kingdom declared DNP “extremely dangerous and not fit for human consumption” in 1938. But because the chemical is used in some pest control products, it is not illegal. The drug can be purchased online.

Parry had taken eight of the pills, when two is considered a lethal dose, according to her mother. The overdose caused Parry's metabolism to soar to dangerous levels, in a process described by her mother as being "burned up from the inside," according to The Guardian.

Parry is the fifth person in the UK to have cause of death attributed to DNP.

West Mercia police published a tribute to Eloise Parry, written by her mother, in which she warns others about the dangers of DNP.