Attorney General Janet Mills is warning Mainers about a recent strain of heroin turning up in Maine. The drug contains an additive that causes users to overdose very quickly.

The heroin contains a drug called fentanyl and Mills says it's fifty times stronger than straight heroin. A new admixture called Acetyl fentanyl or the mixture of caffeine, heroin, and fentanyl is causing users to overdose much quicker than in cases of straight heroin.

100 deaths around the country have been attributed to the drug, which is used to treat cancer patients' pain. It's similar to morphine in the opioid category, according to WebMD, acting on specific receptors in the brain and spinal cord to decrease your response to pain.

It was believed that actor Philip Seymour Hoffman used fentanyl-laced heroin and that's what killed him. CNN reported later, however, that it was mixture of heroin, cocaine, and amphetamines that caused his death.

AG Mills warns that any substance, whether straight heroin or a mixture, can be fatal.