McNeff passed away at 37 years old in August and her cause of death has been shared.

Bodybuilding champion Hayley McNeff passed away suddenly in August at the age of 37. At the time of her death, the cause was unknown but her obituary stated that she passed peacefully on Aug. 8. On Monday, TMZ reported that McNeff’s death was caused by a drug overdose.

The cause of death, which was revealed by the Massachusetts Executive Office of Public Safety, was acute intoxication from a mix of heroin, fentanyl, 4-ANPP, cocaine, and norbuprenorphine. It was officially listed as accidental.

McNeff enjoyed athletics from a young age and was able to turn it into a career in fitness. She hailed from Concord and earned an Arts degree from the University of Massachusetts Amherst. She later took part in graduate studies in psychology as she was interested in helping others in many avenues.

Hayley McNeff Instragram

The Bodybuilding Career of Hayley McNeff

Hayley McNeff showed great interest in skiing, equestrian, and board diving as a youth. As she continued on, McNeff became interested in bodybuilding and was able to become very successful at her peak.

McNeff became a well-known competitor in the mid-2000s. She won multiple competitions during her career, highlighted by a first-place finish during the 2009 East Coast Classic, where she finished at the top overall.

McNeff went onto become featured in the documentary “Raising The Bar.” Many fans took to social media to share their condolences while her obituary shared many traits.

Hayley McNeff’s death fell in line with an unfortunate string in the bodybuilding world. Since then, others have tragically passed as well. This week, Classic Physique competitor Fabiano Andrade passed away just weeks after competing during the 2025 Musclecontest Brasil Pro. According to one source, Andrade’s death was the cause of an accident. Also sharing that he would be covered with an Olympia medal around his neck.

In October, former bodybuilding champion and fitness influencer Ricardo Nolasco dos Santos died in Novo Hamburg in southern Brazil. Santos, who is best known as Kadu Santos, won numerous bodybuilding titles during his career while becoming a well-known influencer on social media. He had just proposed to his girlfriend, Sabrina Wollman, on stage following an event in July.

Like many others, Hayley McNeff made an impact on others and that was shown by the outpouring of comments following her death. In August, McNeff’s father, Dave, spoke with PEOPLE after the news spread around the world.

“Hayley was like a beam of light in this world. She had boundless energy and was very determined to achieve whatever she set out to do. She set her sights on bodybuilding and fitness and achieved the highest success that sector offered. She loved us and we love Hayley very much, we miss her madly.”

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