More than a month after Hayden Panettiere died at 36, South Carolina officials have released the final determination on her cause of death.
The Greenville County Coroner’s Office said Panettiere died from the toxic effects of fentanyl, 4-ANPP, alprazolam, methocarbamol and quetiapine. Her death was ruled an accident, according to the Associated Press.
Panettiere was found unresponsive at a residence in Greenville, South Carolina, on Aug. 16, five days before her 37th birthday. Paramedics performed CPR and other advanced resuscitation efforts for more than 40 minutes before she was pronounced dead.
An autopsy completed the following day found no signs of trauma that contributed to her death, but the cause and manner remained pending while officials waited for toxicology and additional studies.
The Toxicology Results Ended a Month-Long Wait for an Official Cause
The coroner’s Sept. 22 statement identified fentanyl and 4-ANPP, which AP described as a chemical byproduct of fentanyl, along with alprazolam, a muscle relaxant and a medication used to treat serious mental health conditions.
The office did not release additional details from the full autopsy report.
Kasey Kitchen, a publicist for Panettiere’s family, told AP after the ruling that “the investigation is still ongoing and the case is complex.” Greenville Police separately confirmed that their investigation into her death remains active.
The continued investigation does not change the coroner’s classification of the death as accidental.
Earlier Reports Came Before Toxicology Was Complete
Questions about a possible overdose surfaced immediately after Panettiere’s death. Dispatch audio referenced a possible overdose, while later reports cited unnamed law enforcement sources who believed fentanyl may have been involved.
Those accounts were published before the coroner had completed toxicology testing. As recently as Sept. 14, officials emphasized that they had not yet issued a final cause or manner of death.
TMZ reported at the time that investigators were examining whether Panettiere had taken a counterfeit or contaminated pill, but the outlet’s sources acknowledged that their theory depended on the pending toxicology results.
The Sept. 22 coroner’s ruling establishes the substances involved in her death but does not publicly establish where they came from or confirm the earlier reports about how they were obtained.
Panettiere Had Spoken Publicly About Addiction and Recovery
Panettiere had discussed alcohol and substance use publicly years before her death, including periods of treatment while she was starring on Nashville.
She also spoke about postpartum depression following the birth of her daughter, Kaya, and later described the effect that early fame, addiction and personal loss had on her life.
Her career began in childhood with commercials and soap operas before she became widely known as Claire Bennet on Heroes. She later played Juliette Barnes on Nashville and returned to the Scream franchise as Kirby Reed.
Panettiere revisited many of those experiences in her 2026 memoir, This Is Me: A Reckoning, including the pressures of growing up in the entertainment industry and her efforts to address addiction.
Her representative confirmed her death to People in August. Panettiere is survived by her daughter, Kaya, whom she shared with former professional boxer Wladimir Klitschko.