Stephanie Buttermore Cause of Death: Fitness Influencer and Cancer Researcher Dead at 36
The fitness and bodybuilding community is in mourning. Stephanie Buttermore, one of YouTube's most beloved fitness influencers, died suddenly on or around March 6, 2026, just days after celebrating her 36th birthday. Her fiancé, bodybuilder Jeff Nippard, broke the devastating news to their millions of followers Friday. A cause of death has not been disclosed.
Stephanie Buttermore Cause of Death: What We Know
Buttermore was just 36 years old when she died, and no cause of death has been shared publicly. Jeff Nippard's team described her passing as "sudden" in a statement posted to his Instagram and YouTube accounts.
Her death came as a shock to the fitness community. Just two weeks before she died, Nippard posted a Valentine's Day photo of the two of them together on his couch, with Buttermore flashing a bright smile and looking healthy. She celebrated her birthday on February 25.
Her family has requested full privacy as they process the loss, and no further details about the circumstances of her death have been released.
Jeff Nippard's Heartbreaking Announcement
Nippard's team posted an "important announcement" made with "profound sorrow" across Instagram and YouTube on March 7, 2026. The statement described their decade-long relationship and honored Buttermore's memory.
The statement read in part that Buttermore "will be remembered for her warmth and compassion, her love for her family, and her PhD research on ovarian cancer." The family asked for privacy as they navigate the tragic loss.
Comments were shut off on posts announcing her death, but fans flooded the couple's Valentine's Day photo to pay tribute. Fellow influencer Buff Bunny wrote that heaven had gained an amazing angel and expressed prayers for Nippard and the family.
Who Was Stephanie Buttermore?
Stephanie Buttermore was a fitness influencer and doctor who researched ovarian cancer throughout her career. She built a YouTube following of more than one million subscribers and gained particular prominence through her "All In" challenge, where she ate upward of 10,000 calories a day to promote healthy weight gain and body positivity for women.
Before her death, Buttermore held a PhD in Pathology and Cell Biology from the University of South Florida. She pursued both fitness content creation and active ovarian cancer research simultaneously, making her one of the most academically accomplished figures in the influencer space.
Her Final Instagram Post and Social Media Break
Buttermore had stepped back from social media nearly two years before her death, citing dramatically improved mental health as a result. Her final Instagram post, published in May 2024, was headlined with a reflection on what she had learned from taking a break from the platform.
In that post, Buttermore wrote that her anxiety had once been almost crippling, to the point where she felt she could not breathe or leave her house. Being off social media had changed all of that, and she said she no longer experienced highs and lows from the platform.
She added that stepping away made her feel far more present with her family and with Nippard, saying family time had become fully protected time, free from phones and notifications.
Stephanie Buttermore and Jeff Nippard's Love Story
Nippard and Buttermore's relationship began when the Canadian bodybuilder slid into her DMs. Their first date was a shoulder workout, and the pair became partners in both life and content creation over the next decade.
The couple got engaged in October 2022. Nippard wrote at the time that it had been an amazing journey of growth and love and that he could not wait for the next chapter together.
The fitness world continues to pour out tributes for Buttermore, whose impact on body positivity, mental health conversations, and cancer research left a mark that extended far beyond her follower count.
