Actress Hayden Panettiere died from an overdose of fentanyl and other drugs.

An autopsy revealed that Hollywood actress Hayden Panettiere died from the toxic effects of fentanyl, Xanax and several other medications on her body.

Panettiere, best known for her roles in the television series “Heroes” and “Nashville,” died in mid-August at the age of 36. She did not hide the fact that she struggled with drug and alcohol addiction.

The Greenville County Coroner in South Carolina determined that the actress's death was the result of an accident, and no injuries were found on her body that could have contributed to her death.

Pathologists also found that Panettiere's blood contained metacarbamol (a muscle relaxant, a drug that reduces muscle tone), as well as quetiapine, an antipsychotic drug that is used to treat some mental illnesses.

Fentanyl is a synthetic opioid that has caused the deaths of hundreds of thousands of Americans in the past five years alone.

The coroner's office said emergency personnel tried to revive the actress and get her heart started again, but those attempts were unsuccessful.

It is reported that the US Drug Enforcement Administration will be involved in the investigation into Panettiere's death.

As stated in the police report on the actress's death, when emergency services arrived at Panettiere's home, her ex-boyfriend Brian Hickerson (who has admitted to abusing her in the past) and her brother Zach were nearby.

A few months before her death, Panettiere published a memoir detailing her problems with drug addiction and postpartum depression.

Panettiere wrote that she first tried drugs at the age of 16, when she appeared on the red carpet during the premiere of the television series “Heroes.” Then one of her colleagues gave her what he called a “feel good pill” to cheer her up.

“I had no idea then that this couldn’t be done. I didn't know what doors I was walking through in terms of my addiction,” she told People magazine. “When I grew up, I practically couldn’t live without alcohol and drugs.”

Panettiere's brother Jansen died of heart disease at the age of 28. In her book, the actress admitted that he also suffered from drug addiction and, among other things, took heroin and cocaine, which led to his death.