A newly released coroner's report says that actor and martial artist Richard Norton died of sudden cardiac arrest "following self-administration of recently commenced peptide therapy." Norton, known for Hong Kong action films including 1997's "Mr Nice Guy" and more recently the latest "Mad Max" films, died on March 30, 2025, at the age of 75, and his cause of death was not public at the time.

The two compounds named are CJC1295 and Ipamorelin, which are commonly blended together to stimulate growth hormone production and assist recovery. Norton was under a doctor's supervision for the therapy, having told that doctor he had previously used the drugs under another physician's guidance for fatigue, reduced physical recovery, shoulder pain and loss of lean muscle mass.

The dose he was actually taking

Two days before he died, Norton told his nurse he had been taking "double the prescribed dose" of both peptides. The nurse advised him that "he ought to only administer the prescribed dose," which is the detail that turns this from a story about a supervised protocol into a story about what happens when the supervision is only advisory.

How fast it moved

Norton took blood tests before being approved to begin peptide therapy less than two weeks before his death, and for the following week he reported feeling fine and said the treatment was working. A few days after the check-in with his nurse he complained of feeling "hot and flushed," then collapsed and became unresponsive. Paramedics performed CPR after observing cardiac arrest and took him to hospital, where he died two days later.

What the coroner said about the category

The coroner did not hedge on unapproved peptides, noting they are not approved by Australia's health regulators or "any global regulatory authority for human use," that their use is "mostly considered experimental in humans," and that their "toxicology is largely unknown." Australia's ABC News reported that this is believed to be the first death in the country known to be caused by unapproved peptide use.

Bottom line

Some peptides have cleared clinical trials and are legally prescribed. CJC1295 and Ipamorelin have not, and the coroner's finding is the clearest official statement yet on what remains unknown about the ones that circulate anyway.