Matthew Perry's cause of death has been confirmed as the acute effects of ketamine.

The "Friends" star passed away at the age of 54 at his California home on Oct. 28.

The Los Angeles County Medical Examiner’s Office identified ketamine as the primary cause of Perry's death.

Ketamine is a dissociative anesthetic with hallucinogenic effects, according to the U.S. Drug Enforcement Agency.

Perry's death was deemed accidental, with contributing factors including drowning, coronary artery disease, and the effects of buprenorphine (used for opioid use disorder).

The coroner report did not specify how Perry was using ketamine.

Ketamine therapy is an FDA-approved treatment for mental illnesses like depression and anxiety, administered through infusion, injection, or inhalation.

Perry was found unresponsive in a jacuzzi at his Pacific Palisades home and pronounced dead of an apparent drowning on Oct. 28.

Perry's cause of death was pending a toxicology report and further investigation before being confirmed.

The actor's death certificate initially listed the cause of death as deferred.

There were no obvious signs of trauma or foul play, according to law enforcement sources.

It remains unclear whether Perry had relapsed, as ketamine can be used both therapeutically and recreationally.

Perry had been open about his struggles with drugs and alcohol, spending $9 million to overcome addiction.

The actor faced health issues, including a near-death experience in 2019 after his colon erupted, leading to a two-week coma.

Perry expressed his desire to be remembered for helping people with their sobriety journey rather than for his role in "Friends."