The cause of death of actress Hayden Panettiere, best known for her roles in Heroes and Nashville, has been officially revealed more than a month after she died at the age of 36.
According to the Greenville County Coroner’s Office in South Carolina, Panettiere died from the toxic effects of several substances, including fentanyl. Her death was classified as an accident. The toxicology findings also identified 4-ANPP, alprazolam, methocarbamol and quetiapine in her system.
Panettiere was found unresponsive at an apartment in Greenville on August 16. Emergency responders were called after a report of cardiac arrest and attempted lifesaving measures for more than 40 minutes. She was ultimately pronounced dead at the scene.
The coroner previously said that the autopsy found no signs of trauma that would have contributed to her death. At the time, officials said additional testing was needed before the cause and manner of death could be established.
Her death brought an abrupt end to a career that began when she was a child. Panettiere appeared in commercials and television productions from a very young age before gaining wider attention through films including Remember the Titans and Ice Princess.
Her biggest television breakthrough came with NBC’s Heroes, which premiered in 2006. She played Claire Bennet, a high-school cheerleader who discovers she has extraordinary regenerative abilities. The role turned Panettiere into a recognizable young star and made her a familiar face to millions of American television viewers.
She later took on another major role in the ABC musical drama Nashville. Beginning in 2012, Panettiere portrayed Juliette Barnes, a talented but troubled country music performer trying to navigate fame, relationships and the pressures of the entertainment industry. She performed many of the songs associated with the character and received two Golden Globe nominations for her work on the series.
Panettiere also appeared in movies including Scream 4 and Scream VI, as well as I Love You, Beth Cooper and Remember the Titans. Her career stretched across television, film and music, making her one of the recognizable American performers who had grown up in the spotlight.
Away from the screen, Panettiere had spoken openly about difficult periods in her life. She discussed struggles involving alcohol, substance use and postpartum depression, and she later entered treatment while working on Nashville. In May 2026, she released her memoir, This Is Me: A Reckoning, in which she reflected on growing up famous and the personal challenges she experienced throughout her life.
Her family had previously asked the public for privacy following her death. Her father, Skip Panettiere, described her as someone who brought love and joy to the people around her and to the millions who watched her work.
The newly released coroner’s findings provide the official cause and manner of death, but authorities have indicated that the broader investigation has not necessarily ended. Greenville police have said their investigation remains ongoing, while the family has also called for further answers surrounding what happened.
Panettiere leaves behind a career that began in childhood and included some of the most recognizable television roles of the 2000s and 2010s. For many fans, she will be remembered most vividly as Claire Bennet from Heroes and Juliette Barnes from Nashville — two performances that helped define her place in American television.
