More Than Half of GLP-1 Users Reported Seeking Follow-Up Care for Side Effects, Phenomix Sciences Report Finds

Menlo Park, Calif., March 5, 2026 – In recognition of Obesity Care Week, Phenomix Sciences (Phenomix), the first commercial precision obesity medicine biotechnology company, today released new findings from its “2026 State of Obesity Treatment Report: Progress, Gaps, and the Path to Personalized Care” report. Drawing on a national survey of U.S. patients with overweight or obesity who have used GLP-1s, the report reveals that real-world use of GLP-1 medications frequently involves additional medical care and out-of-pocket costs beyond the prescription itself for a subset of patients.

Key findings from the report include:

Side effects often require medical care: More than half (52%) reported seeking some form of follow-up care for side effects, ranging from telehealth or doctor visits to urgent care, and a small number reporting hospitalization.
Out-of-pocket costs can be significant: Among those who sought follow-up care for side effects, nearly half reported spending more than $1,000 out of pocket, including a small subset who reported costs above $5,000.
Weight loss outcomes vary widely: While some respondents reported meaningful weight loss (39%), more than half (55%) experienced challenges such as weight loss plateaus and limited response. In fact, 10% of patients experienced weight gain while on these medications.
Real-world use is more complex than the prescription alone: Taken together, these findings show patient outcomes on GLP-1s are more complex in the real world than in clinical studies, resulting in ongoing care needs, follow-up, and total out-of-pocket costs over time.

Together, these findings show that real-world GLP-1 use is often more complex across patient populations, affecting not only outcomes but also the level of care, follow-up, and out-of-pocket costs patients may face over time.

“GLP-1s have changed the conversation around obesity for the better, but patient responses, side effects, and long-term needs still vary widely,” said Natalie Ikeman, Obesity Medicine Specialist at Bhatti Weight Loss Center. “Having tools that help us better understand why a patient may respond differently, and guide more informed treatment decisions, is becoming increasingly important as obesity care evolves.”

“These findings point to an important takeaway: people do not respond to GLP-1s in the same way,” said Mark Bagnall, CEO of Phenomix Sciences. “While these medications represent meaningful progress for obesity care, the data underscores that obesity is not a single disease and that no one treatment will work equally well for every patient. As with other chronic conditions, like cancer, improving outcomes in obesity care will increasingly require more precise, individualized approaches rather than one-size-fits-all solutions.”

These findings are part of Phenomix’s broader 2026 State of Obesity Treatment Report, which explores patient perceptions, real-world outcomes, education gaps, and downstream care considerations associated with GLP-1 use. To review the full report, click here.

For more information about Phenomix Sciences and supporting research, visit phenomixsciences.com.

About Phenomix Sciences
Phenomix Sciences is a precision obesity biotechnology company transforming obesity care by putting patients at the center of therapeutic innovation. Through proprietary genetic testing, advanced analytics, rich clinical data, and technology exclusively licensed from Mayo Clinic, Phenomix delivers individualized insights into how patients respond to specific weight loss interventions. These insights not only inform clinical decision-making for patients but also help pharmaceutical and medical device partners refine trials, identify high-responder populations, and accelerate the development of more targeted, effective therapies. By aligning patient biology with drug discovery, Phenomix is shaping a more personalized and impactful future for obesity treatment. Phenomix is backed by Health2047, the innovation arm of the American Medical Association, which helps startups transform bold ideas into solutions that change healthcare for the better. Learn more at www.phenomixsciences.com.

Media Contact:

phenomix@ampublicrelations.com

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