A new large-scale genetic study has begun to clarify why all patients don’t lose weight on GLP-1 receptor agonists.
The 23andMe Research Institute published an analysis in Nature identifying genetic variants influence the efficacy and tolerability of GLP-1s. Researchers conducted a genome-wide association analysis of 27,885 individuals treated with GLP-1–based therapies. The study integrated genotype and phenotype data from 23andMe, clinical trial cohorts and population biobanks.
The cohort skewed heavily toward European ancestry, with 78.3% of patients comprising the cohort. The demographics were also primarily female, making up 82.4% of the patients.
Based on the data collected, researchers found that differences in an individual’s semaglutide and tirzepatide response may be measurable genetic variables that impact weight loss.
The analysis isolated a specific genetic marker within the GLP-1 receptor gene, identified as rs10305420. The data from the cohort indicated that each copy of this variant carried by an individual correlates with an additional 0.76 kg of weight reduction. For clinicians, these new findings are finally illuminating the ‘black box’ of GLP-1 weight-loss variability, identifying biological factors that lifestyle and adherence alone cannot explain.
How Genes Effect GLP-1 Response
The study identified biological associations that explain functional resistance to GLP-1 therapies. When combining genetic markers with clinical history, researchers found a vast spectrum of real-world variability. Predicted weight loss ranged from 6% to 20% of starting body weight.
The analysis found that multiple loci contribute modest effects that collectively shape clinical outcomes. Some of these include weight loss, glycemic response and tolerability. Researchers specifically identified receptor-level mechanisms as primary drivers of reduced treatment efficacy. These factors include receptor binding, signaling efficiency, downstream insulinotropic effects, and central appetite regulation.
The study also linked variants in the glucose-dependent insulinotropic polypeptide receptor to increased rates of nausea and vomiting.
The Future Of Weight Loss Treatment
While the findings add biological context to response variability, the data doesn’t change how doctors are currently prescribing standards. Outpatient clinics increasingly treat obesity as a chronic disease. Primary care clinicians have the largest percentage of written GLP-1 prescriptions, followed closely by nurse practitioners.
While it may not impact the amount of prescriptions, the data will help clinicians better understand it.
“Primary care physicians have the most comprehensive view of their patient’s medical history and ongoing care and are central to managing their overall health,” said Justin Wu, the vice president of Clinical Innovation and Quality at Omada Health, in a statement. “There’s also a clear need for programs that provide support between office visits, offering proven wraparound services that address patients’ unique health needs—beyond focusing solely on the number on the scale.”
Back in April, the 23andMe Research Institute announced study results would be integrated into consumer-facing tools. The organization hopes to eventually provide personalized estimates and reports of GLP-1 weight loss response and side effect risk. As genetic reports become more widely available, clinicians may see more patients arrive with risk information when considering GLP-1 therapy. Some patients may also pursue telehealth pathways, bypassing traditional clinic-based evaluation.
This trend has been catalyst for rapid growth in telehealth platforms prescribing GLP-1s, driving concerns among clinicians and regulators. A survey by Omada Health recently shared that 67% of physicians believed weight-loss prescriptions issued through third-party telehealth providers placed patient safety at risk.
The Rise of the Medical Concierge For Weight Management
While 23andMe has entered the “GLP-1 economy,” major technology companies are rapidly expanding their presence in the space. With GLP-1 medications becoming more ubiquitous, the use of personalized coaching and genetics-informed obesity care has become more mainstream.
Google recently launched its Personal Health Coach, which integrates Continuous Glucose Monitor data with electronic medical records. This provides real-time metabolic feedback to users. Similarly, Microsoft expanded Copilot Health to include weight management recommendations informed by lab results and clinical notes.
A growing ecosystem of agentic AI tools have also entered the market. These tools range from snap-and-log calorie trackers to predictive metabolic wearables connected to AI-driven coaching systems.
McKinsey Health Institute has described this shift as a “metabolic health revolution,” highlighting the growing role of technology in supporting long-term metabolic health and weight management.
That shift is already reshaping consumer behavior. Patients are increasingly adopting full-spectrum health optimization platforms that combine genomic sequencing, microbiome testing, sleep analysis, hormone tracking and wearable biometric data.
The rise of these tools has also fueled broader interest in AI-powered health guidance. Consumers are turning to large language models as a way to expand access to health information and personalized wellness support.
Clinicians and researchers are directing their attention on the impact these AI models may have on patients. A physician-led study published in Cureus evaluated diet and exercise recommendations generated by ChatGPT, Claude AI, DeepSeek, and Google Gemini. While most responses broadly aligned with guideline-based recommendations, researchers found that all models struggled to provide quantitative guidance on carbohydrate and added sugar intake.
Some recommendations also lacked clinical specificity and required physician interpretation and oversight.
Physician Touchpoints Can Anchor the GLP-1 Revolution Beyond AI Models
With one in eight adults now reporting GLP-1 use, there is no sign of its usage slowing down. These consumer trends are reinforcing the need for care models that support patients beyond medication alone. For clinicians, it also increases pressure to integrate AI into workflows as patients are using the tools for health questions.
“Physicians and care teams that do not acclimate themselves to AI will be left behind by those who do,” said Nzinga Loew, CEO of advisory firm Pygmalion Health. “A structured workflow is necessary, so the patient isn’t missing anything and isn’t getting misinformation.”
Patients are beginning to arrive at routine visits with AI-generated questions and treatment recommendations already in hand. But researchers and clinicians say physician oversight remains critical to long-term GLP-1 success.
While medications, such as semaglutide and tirzepatide, can initiate weight loss, sustained outcomes still depend on adherence, nutrition and ongoing support. Those needs often require human guidance beyond automated care tools.
“Human touch will always be needed,” Loew said. “Patients are going to AI, but they are bringing that information to their physician. We just need to ensure that both the physician and patients aren’t burnt out by all this data.”
