Zepbound vs Trulicity: Two Eli Lilly GLP-1 Drugs Compared

Last reviewed: May 12, 2026 Last updated: May 12, 2026

Written by: Jay Hastings , CEO of PlexusDx

Jay Hastings is the CEO of PlexusDx, a precision health company focused on genetic testing, blood biomarker insights, and personalized wellness recommendations. He has more than 20 years of experience across healthcare innovation, genomics, laboratory operations, healthcare investing, and strategic finance. His work has included scaling healthcare startups, leading CLIA lab integrations, and helping expand consumer access to precision health tools.

Medically reviewed by: Jayden Lee, PharmD, EMBA

Jayden Lee, PharmD, EMBA, is the PlexusDx Medical Science Liaison with a PharmD and MBA specializing in pharmacogenomics and clinical product development, with a proven ability to bridge the gap between genomic research and practical patient outcomes. Dr. Lee has more than 10 years of professional experience in clinical pharmacy, academia, and research.

Part of the PlexusDx Education Hub, where we unpack GLP-1 therapies, weight-management protocols, and the genetic factors sitting underneath every metabolic decision. Browse all Peptides & GLP-1 education

What follows is independent editorial analysis. PlexusDx holds no commercial relationship with Eli Lilly or the makers of the products discussed here.

Zepbound and Trulicity are an unusual pairing because both come from Eli Lilly, yet they were built for different jobs. One is a dual-incretin molecule cleared for weight management; the other is a once-weekly GLP-1 drug used in type 2 diabetes. Below we line them up on how they work, what the trials say, how they are tolerated, and what a month tends to cost, then look at the genetics that sit upstream of either choice.

Two Eli Lilly molecules, two different jobs

Trulicity reached the U.S. market in 2014 as a once-weekly treatment for type 2 diabetes; its active ingredient is dulaglutide. Zepbound is the weight-management brand for tirzepatide, cleared for chronic weight management in 2023 and, a year later, for obstructive sleep apnea in adults with obesity. Same manufacturer, different molecules, different labels, which is exactly why patients end up comparing them.

Receptor engagement: dual agonist versus GLP-1-selective

The mechanical dividing line is how many incretin receptors each molecule touches. Tirzepatide is a GIP/GLP-1 dual agonist, engaging both the glucose-dependent insulinotropic polypeptide receptor and the GLP-1 receptor. Dulaglutide, semaglutide, and liraglutide are GLP-1-selective. Retatrutide, a GLP-1/GIP/glucagon triple agonist, remains investigational and is not FDA-approved as of April 2026. Despite the difference, every one of these compounds acts on the GLP-1 receptor to slow gastric emptying, blunt post-meal glucose spikes, and amplify satiety signaling.

What each drug is cleared to treat

Labels matter here because they drive both prescribing and coverage. Across the class, FDA clearances break down by indication: Trulicity (dulaglutide) for type 2 diabetes in 2014; Zepbound (tirzepatide) for chronic weight management in 2023 and obstructive sleep apnea in 2024 under SURMOUNT-OSA; Mounjaro (tirzepatide) for type 2 diabetes in 2022; Ozempic (semaglutide) for type 2 diabetes in 2017; Wegovy (semaglutide 2.4 mg) for weight management in 2021; Rybelsus (oral semaglutide) for diabetes in 2019; and Victoza (liraglutide) for diabetes in 2010. Retatrutide is investigational.

Trial evidence, including the head-to-head signal

The two molecules were studied in separate programs. Dulaglutide's evidence base runs through the AWARD trials; tirzepatide's sits in SURMOUNT for weight management and SURPASS for diabetes. A partial bridge exists: SUSTAIN 7 pitted semaglutide 1 mg against dulaglutide 1.5 mg, and SURPASS-2 compared tirzepatide with semaglutide 1 mg in type 2 diabetes. There is no clean, direct Zepbound-versus-Trulicity trial, so any comparison is stitched from different populations, doses, and endpoints; read each study on its own terms rather than as a class-wide verdict.

Tolerability and the shared class warning

Both molecules carry the same boxed warning for thyroid C-cell tumor risk seen in rodent studies, and both are contraindicated for anyone with a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2. Day to day, the most common complaints are gastrointestinal, including nausea, vomiting, diarrhea, and constipation, and they tend to peak while the dose is being escalated. Uncommon but serious events include pancreatitis, gallbladder problems, and acute kidney injury when dehydration is in play.

What a month actually costs

As of April 2026, published U.S. list prices for the FDA-approved brands in this category span roughly $815–$1,620 per month (manufacturer list pricing). What a given person pays, though, turns on insurance design, the indication written on the prescription, savings-card eligibility, and whether a licensed compounding pathway is available. List price is rarely the number that lands on the statement.

The genetic layer both drugs share

Whichever molecule a clinician lands on, the biology underneath is the same. Common variants in FTO, the fat-mass and obesity-associated gene, shape appetite regulation and adiposity set-point; GLP1R encodes the very receptor every GLP-1 compound engages; MC4R sits at the center of energy balance; and TCF7L2 ties into glucose homeostasis and GLP-1 secretion. These are pathway-level variants: they do not predict how you will respond to Zepbound or Trulicity, but they describe the metabolic terrain a prescriber is working within.

PlexusDx offers semaglutide and tirzepatide through its Weight Management Protocols; it does not sell, distribute, or prescribe dulaglutide. The Precision Peptide Genetic Test analyzes 14 pathways, 49 peptides, 150+ genetic insights, including the FTO, GLP1R, MC4R, and TCF7L2 variants that frame your baseline appetite-regulation and energy-balance biology. Seeing that profile before you commit to a protocol is the test before you invest idea: fewer assumptions, a better-informed conversation with your provider.

Related reading on PlexusDx: Zepbound Generic Name, Zepbound for Weight Loss, What is Zepbound, Zepbound Cost.

Disclaimer: This article is educational. PlexusDx offers semaglutide and tirzepatide through its Weight Management Protocols and does not sell, prescribe, or recommend dulaglutide. The Precision Peptide Genetic Test analyzes how your genes influence peptide-related biological pathways; it does not predict response to any specific medication. Consult a qualified healthcare provider before beginning any peptide protocol.

Start with the biology. Take the Precision Peptide Genetic Test, or explore the Weight Management Protocols.

Frequently Asked Questions

Are Zepbound and Trulicity made by the same company?

Yes. Both are Eli Lilly products, but they contain different active ingredients and carry different labels. Zepbound is tirzepatide, cleared for chronic weight management and sleep apnea, while Trulicity is dulaglutide, a once-weekly option approved for type 2 diabetes. Same maker, distinct molecules and uses.

Is Trulicity approved for weight loss?

No. Trulicity (dulaglutide) is FDA-approved for type 2 diabetes, not chronic weight management. Zepbound (tirzepatide) holds the weight-management indication in this pairing. Prescribing decisions and insurance coverage often hinge on which label applies, so the approved indication is worth confirming with a provider first.

Does the Precision Peptide Genetic Test say which drug will work better?

No. It does not predict response to Zepbound, Trulicity, or any medication, and it is not a pharmacogenomic test. It reads pathway-level variants in FTO, GLP1R, MC4R, and TCF7L2 that shape baseline appetite and energy-balance biology, context that applies no matter which compound a provider considers.

Why is there no direct head-to-head trial?

The two molecules were developed in separate programs, AWARD for dulaglutide and SURMOUNT and SURPASS for tirzepatide. The nearest bridges are SUSTAIN 7 and SURPASS-2, which both used semaglutide as the comparator. Without a direct study, any Zepbound-versus-Trulicity comparison draws on different populations and endpoints.

Medical and Editorial Standards

Medical review process: This article was reviewed for medical accuracy, scientific clarity, evidence alignment, and appropriate discussion of genetics, medications, supplements, biomarkers, and health-related claims.

Sources and evidence: PlexusDx educational content is developed using peer-reviewed research, clinical literature, reputable medical references, and, where applicable, public health or regulatory guidance. References are included at the end of the article when scientific, medical, or health-related claims are discussed.

Commercial transparency: PlexusDx offers genetic testing, blood biomarker testing, personalized supplement recommendations, and related precision wellness services. Product mentions are intended to help readers understand available options and should not be interpreted as medical advice.

Important disclaimer: PlexusDx educational content is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about medications, supplements, genetic testing, lab testing, or health-related care.