Stephanie Buttermore Cause of Death: No Official Cause Released as Jeff Nippard and Family Request Privacy

The fitness and science communities are still searching for answers. As of Sunday, March 8, 2026 ET — two days after Jeff Nippard's heartbreaking announcement — the Stephanie Buttermore cause of death has not been officially disclosed by her family, her fiancé, or any law enforcement authority. What the world knows is that she died suddenly at 36, appeared healthy on Valentine's Day, celebrated her birthday on February 25, and was gone nine days later. The family has asked firmly for privacy, and that request deserves to be honored.

What We Know: "Sudden Passing" — Nothing More

No cause of death has been shared. Jeff Nippard's team announced on Instagram on March 6, 2026 that Stephanie Buttermore had died suddenly at 36. The statement read: "It is with profound sorrow that we share the sudden passing of Jeff's fiancée and partner of ten years, Stephanie. As many of you know, Stephanie meant the world to Jeff. She will be remembered for her warmth and compassion, her love for her family, and her PhD research on ovarian cancer. We kindly ask for privacy as we navigate this tragic loss."

The lack of an announced cause of death has left many in the fitness and scientific communities searching for answers. The sudden nature of her passing suggests an unforeseen medical event, but the family has requested privacy as they navigate this tragic loss.

Stephanie's Last Known Public Appearance: Valentine's Day, February 14

Nippard posted a Valentine's Day photo of the two of them sitting on a couch, in which Buttermore looks healthy as she flashes a bright smile. Her death comes as somewhat of a shock — Nippard had posted that photo just two weeks before she died, and nearly two weeks later Buttermore celebrated her birthday on February 25.

Buttermore's final comment to Jeff Nippard, on that Valentine's Day post, was simply: "Love you forever." She was unaware those would be among her last public words to the man she had been with for a decade.

Her Final Instagram Post: Mental Health, Anxiety, and Stepping Away

Stephanie Buttermore's last solo Instagram post — published in May 2024 — paints the picture of someone who had genuinely found peace after years of struggle. She wrote: "I no longer struggle with anxiety. At all. It was almost crippling a few years ago to the point I felt I couldn't breathe or leave my house. Now I really don't have to care whether people liked what I posted or if they are saying negative things about me."

As of now, the cause of Stephanie Buttermore's death remains unclear. In recent years she had stepped away from social media to focus on her mental health and deal with the pressures of being constantly in the public eye. She had been planning a return to the platform before her passing.

Who Was Stephanie Buttermore: PhD, Ovarian Cancer Research, and the All In Journey

Stephanie Buttermore did her PhD in Pathology and Cell Biology at the University of South Florida. Her area of research focused on ovarian cancer detection and early screening, where she succeeded in discovering a protein called RHAMM — a protein that could potentially be used as an early screening marker for the disease through a urine test.

What made her a buzzing influencer was that she blended her passion for fitness with her scientific knowledge, informing millions of followers on the science behind exercise and diet. She had garnered over 525,000 followers on Instagram and over 1.17 million YouTube subscribers at the height of her platform.

Jeff Nippard and Stephanie Buttermore: Ten Years Together

Nippard and Buttermore were partners for ten years and got engaged in October 2022. After he slid into her DMs, they spent months video calling for three to four hours every day before Nippard traveled from Canada to visit her in Florida. "Our first date was a shoulder workout and I will never forget it," Nippard joked on Instagram after the engagement was announced.

Funeral service announcements have not yet been made public, though Nippard's team indicated more details would be shared in the coming days. The fitness world is mourning deeply — and respectfully holding space for Jeff Nippard's grief. If you or someone you know is struggling, please reach out to the 988 Suicide and Crisis Lifeline by calling or texting 988.