Hayden Panettiere Could Have Taken 'Killer Cocktail' of Drugs Prior Her Death, Expert Claims: 'These Medications Have Killed Multiple Celebrities'

A psychiatrist believes that Hayden Panettiere could have ingested a "killer" cocktail of drugs before her death.

The actress, 36, passed away in South Carolina on August 16 after police responded to a call about an unresponsive female. Dispatch audio made mention of "cardiac arrest" and an "overdose."

"What I worry about with this is that she could have been on a cocktail of medications that have killed multiple celebrities," Dr. Josef Witt-Doerring told Katie Pavlich Tonight.

The "cocktail" that Witt-Doerring was referring to is a deadly combination of Klonopin and opiates.

"What most people don’t know is that those two drugs together are the celebrity killer, because when you take them at the same time, they cause respiratory depression," Witt-Doerring added. "While they’re sleeping, they stop breathing and die. This is the same combination of drugs that was found with Matthew Perry."

Other stars, including Heath Ledger and Anna Nicole Smith, passed away after ingesting a similar combination of substances.

Panettiere's exposure to drugs began when she was a teenager, but did not spiral into addiction until later in life. The actress was candid about relying on alcohol and Klonopin while dealing with postpartum depression following the birth of her daughter, Kaya, in 2014.

"I started self-harming in the form of substance abuse," she wrote in her May 2026 memoir This Is Me: A Reckoning. "My people-pleasing had built up, and up, it was anger and anxiety and frustration."

Though Panettiere entered rehab in 2020, close friends claimed that she had recently struggled with her sobriety.

Her on-again, off-again boyfriend Brian Hickerson even guided police to a "bag of medication" she had been taking prior to her death.

"Who gave this person with a history of addiction this bag of dangerous medication?" Witt-Doerring demanded to know.

Hickerson was present in the South Carolina apartment where the actress took her last breath after they traveled there together from Los Angeles, Calif.

Panettiere's cause of death has not been determined and it is unclear which medications the actress was consuming before she died.

Close friends claimed that she had been recently dealing with "severe" pain and appeared to slip back into habits she relied on during active addiction.

"I know she suffered earlier this year with her back," her longtime hairdresser and friend, Erick Orellana, told Page Six. "At one point, it was even hard for her to move her legs.”

Panettiere confessed in her memoir that an "old neck injury" had caused her to return to opioids in the past.

In March, she was hobbling on crutches alongside Hickerson at Los Angeles International Airport. At the time, she claimed she was suffering from a pinched nerve.

The couple last broke up in 2022 after a physical altercation outside of a Los Angeles, Calif., bar. Over the course of their four-year relationship, Hickerson was accused of abusing Panettiere on multiple occasions.

He was even sentenced to 45 days in jail for several domestic violence charges.

"She really did want to get better and stay sober," one insider told People of her relationship with Hickerson. "But the person she felt safest being around when she was struggling wasn’t necessarily the person who was going to help her get there."