Are all GLP-1 drugs the same? No — and the differences matter for personalization.
A 2024 nationwide analysis of 1.1 million patients with obesity found that different GLP-1 receptor agonists had strikingly different effects on cancer risk over a 5-year follow-up [1]. Semaglutide was associated with a 55% lower risk of gastrointestinal cancers (hazard ratio 0.45) compared to matched controls, while liraglutide was linked to a 70% higher risk of thyroid cancer (HR 1.70) and a 62% higher risk of respiratory cancers (HR 1.62) [1]. This means that a personalized recommendation would need to consider which specific GLP-1 drug a patient receives, not just the class as a whole. The same study also found that risk reductions varied by cancer type — breast cancer risk dropped 28% (HR 0.72), prostate cancer 32% (HR 0.68), and female genital cancers 39% (HR 0.61) — suggesting that a patient's personal or family cancer history could guide drug choice [1].
Your genes influence how well GLP-1 drugs work and how safe they are.
A 2026 review of pharmacogenomics in GLP-1 therapy identified specific genetic variants that directly affect treatment outcomes [4]. Variants in the GLP1 receptor gene (GLP1R, specifically rs6923761 and Gly168Ser) and in the beta-arrestin-1 gene (ARRB1, specifically rs140226575 and Thr370Met) were shown to alter glycemic response and weight loss effectiveness [4]. This means two patients on the same dose of the same drug can have meaningfully different results simply because of their DNA. Additionally, while GLP-1 drugs themselves are not broken down by the liver's CYP enzymes, many patients take other medications alongside them — such as antidepressants or beta-blockers — that are metabolized by CYP2D6. Genetic variations in CYP2D6 can change how fast these co-medications are processed, indirectly affecting both efficacy and side effect risk [4]. Ethnic differences in CYP2D6 allele frequencies further underscore that a one-size-fits-all dosing approach is inadequate [4].
GLP-1 drugs affect multiple organs — personalization may extend beyond diabetes and obesity.
A 2025 review synthesized evidence that GLP-1 receptor agonists have beneficial effects on the liver (reducing fat accumulation and inflammation in metabolic fatty liver disease), kidneys (reducing inflammation and stabilizing function in diabetic kidney disease), and the cardiovascular system (reducing major adverse cardiac events) [3]. The same review also highlighted emerging evidence for neuropsychiatric benefits, including reductions in depressive symptoms, anxiety, and substance use, as well as lower risk of Alzheimer's and Parkinson's disease [3]. These effects are mediated by both direct receptor activation and indirect pathways, and genetic polymorphisms in the GLP1R gene influence the magnitude of these benefits [3]. This means a personalized recommendation could eventually consider a patient's full health profile — not just weight and blood sugar, but also liver health, kidney function, cardiovascular risk, and even mental health history — to select the most appropriate GLP-1 agent and dose.
About These Sources
This answer is built on 5 peer-reviewed studies — published from 2024 to 2026, 5 from 2024 or later, 1 in Q1 journals — selected as the most relevant from 5 studies that passed quality screening, drawn from 38 papers retrieved from a database of over 500 million.
Sources used in this answer
Differential Effects of GLP-1 Receptor Agonists on Cancer Risk in Obesity: A Nationwide Analysis of 1.1 Million Patients
In a large cohort study of 1.1 million patients with obesity, semaglutide was associated with a 55% lower risk of gastrointestinal cancers (HR 0.45) while liraglutide was linked to a 70% higher risk of thyroid cancer (HR 1.70), demonstrating that different GLP-1 drugs have divergent effects on cancer risk.
GLP-1 and the cardiovascular system
This review summarizes that GLP-1 receptor agonists like liraglutide, semaglutide, and dulaglutide have demonstrated reductions in cardiovascular outcomes in large trials, and newer dual agonists like tirzepatide achieve greater HbA1c and weight loss, with ongoing trials assessing hard cardiovascular endpoints.
The Expanding Role of GLP-1 Receptor Agonists: Advancing Clinical Outcomes in Metabolic and Mental Health
This 2025 review reports that GLP-1 receptor agonists improve liver fat, kidney function, and cardiovascular outcomes, and emerging evidence suggests neuropsychiatric benefits including reduced depression and lower risk of Alzheimer's disease, with genetic variants in GLP1R influencing therapeutic response.
Integrating Pharmacogenomic Insights in GLP-1 Receptor Agonist Therapy: Direct GLP1R and ARRB1 Variants and Indirect CYP2D6 Influences in Personalized Obesity Management
This 2026 review identifies that genetic variants in GLP1R (rs6923761) and ARRB1 (rs140226575) directly affect glycemic and weight loss response, while CYP2D6 polymorphisms indirectly influence outcomes by altering metabolism of co-prescribed medications like antidepressants and beta-blockers.
Biotechnological Advances in GLP-1 Receptor Agonists: Development, Optimization, and Market Dynamics
This 2025 review discusses biotechnological advances in GLP-1 agonists, including protein engineering to prolong half-life and reduce dosing frequency, and notes potential applications in personalized medicine and combination therapy.