Popular fitness YouTuber and bodybuilder Jeff Nippard announced the sudden death of his fiancée, Dr. Stephanie Buttermore, in an Instagram post on March 6, 2026.
No cause of death was revealed in the post, and Nippard’s team asked for fans to respect his privacy during this time. Dr. Buttermore was 36 years old.
“It is with profound sorrow that we share the sudden passing of Jeff’s fiancée and partner of ten years, Stephanie,” the statement reads.
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“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. Thank you for your understanding and support during this difficult time.”
Fans mourn death of beloved influencer and researcher Dr. Stephanie Buttermore
Dr. Buttermore and Nippard had been in a relationship for a decade. She held four degrees: a BS in Micro/Molecular Biology, an MS in Medical Sciences, Women’s Health, an MS in Medical Sciences, Pathology & Cell Biology, and a PhD in Biomedical Sciences, Pathology & Cell Biology from the University of South Florida.
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Dr. Buttermore, who was usually very active on social media, stopped posting on her personal Instagram account in 2024. She was last featured in a post on Nippard’s Instagram on February 14, 2026.
Like her fiancée, Dr. Buttermore was passionate about health and fitness, using her presence on social media to “educate on the scientific principles of training and nutrition,” as she described on her official website.
As stated in Nippard’s Instagram post, she was also conducting research into ovarian cancer, primarily focusing on early detection screening markers and the molecular mechanisms driving the disease.
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Dr. Buttermore discovered that a protein called Receptor for Hyaluronan Mediated Motility (RHAMM) was up-regulated in certain cells, tissue, and urine, finding that this could be used as an early screener for ovarian cancer via urine tests.
stephaniebuttermore.comDr. Buttermore was researching ovarian cancer and discovered that a chemical in urine could be used to screen for the disease.
Fans are sending their well wishes and condolences to Nippard in the wake of the heartbreaking news, with one writing on Instagram, “Be strong, Jeff. My heart is broken.”
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“I love you Jeff. I can’t imagine what you’re going through. Prayers for you,” another said.
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“Jeff, you are a huge inspiration to me and I cannot fathom what you must be going through. Much love, man,” another wrote.