LOSE WEIGHT WITH MEDICAL SUPPORT — BUILT FOR MEN
- Your personalised programme is built around medical care, not willpower.
- No generic diets. No guesswork.
- Just science-backed results and expert support.
Find out if you’re eligible
Zepbound is manufactured by Eli Lilly and Company, a global pharmaceutical leader headquartered in Indianapolis, Indiana, with over a century of expertise in metabolic disease research. The company developed tirzepatide, Zepbound's active ingredient, as a novel dual receptor agonist targeting both GIP and GLP-1 pathways. Following FDA approval of tirzepatide as Mounjaro for type 2 diabetes in May 2022, Eli Lilly secured separate approval for Zepbound in November 2023 specifically for chronic weight management in adults with obesity. This article explores Eli Lilly's role in developing Zepbound, the medication's mechanism of action, FDA approval process, and how patients can access this prescription treatment.
Quick Answer: Eli Lilly and Company manufactures Zepbound, receiving FDA approval in November 2023 for chronic weight management in adults with obesity.
Zepbound is manufactured by Eli Lilly and Company, a global pharmaceutical corporation headquartered in Indianapolis, Indiana. Eli Lilly has been a significant contributor to metabolic disease research for over a century, including the first commercial production of insulin in the 1920s. The company's experience in diabetes and obesity therapeutics contributed to the development of tirzepatide, the active ingredient in Zepbound.
The development of tirzepatide represents years of research into incretin-based therapies. Eli Lilly's scientists focused on creating a dual agonist that could simultaneously activate both glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. This approach distinguished tirzepatide from existing single-receptor agonists in the market. The company conducted extensive preclinical studies before advancing to human trials to understand the compound's pharmacology and safety profile.
Eli Lilly first received FDA approval for tirzepatide under the brand name Mounjaro for type 2 diabetes management in May 2022. Building on clinical trial data demonstrating significant weight loss effects, the company pursued a separate indication specifically for chronic weight management. This led to the approval of Zepbound in November 2023, making it the same molecule as Mounjaro but marketed and indicated specifically for obesity treatment in adults.
The company maintains manufacturing facilities that comply with FDA current Good Manufacturing Practice (cGMP) standards. Eli Lilly has made substantial investments in the research, clinical trial, and regulatory phases of tirzepatide development, reflecting the complexity of bringing novel obesity therapeutics to market.
LOSE WEIGHT WITH MEDICAL SUPPORT — BUILT FOR MEN
Find out if you’re eligible
Zepbound (tirzepatide) is a prescription medication approved for chronic weight management in adults with obesity or overweight with at least one weight-related comorbidity. It belongs to a novel class of medications known as dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonists. Zepbound is administered as a once-weekly subcutaneous injection, available in doses ranging from 2.5 mg to 15 mg, with a recommended dose escalation schedule starting at 2.5 mg and increasing every 4 weeks as tolerated.
The mechanism of action involves simultaneous activation of two incretin hormone receptors. GIP and GLP-1 are naturally occurring hormones released by the intestine in response to food intake. By mimicking these hormones, tirzepatide influences multiple physiological pathways involved in appetite regulation, glucose metabolism, and energy balance. GLP-1 receptor activation decreases appetite, slows gastric emptying, and enhances insulin secretion when blood glucose is elevated. The addition of GIP receptor activation appears to complement these effects, potentially enhancing weight loss beyond what is achieved with GLP-1 agonism alone. Weight loss occurs primarily through reduced food consumption, as patients typically report decreased hunger and increased satiety.
Common adverse effects include gastrointestinal symptoms such as nausea, diarrhea, vomiting, constipation, and abdominal discomfort. These effects are generally most pronounced during dose escalation and often diminish over time. Serious but less common risks include pancreatitis and gallbladder disease. Zepbound carries a boxed warning regarding thyroid C-cell tumors (based on rodent studies) and is contraindicated in patients with a personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN2), and in those with serious hypersensitivity to tirzepatide.
Important safety considerations include potential interactions with oral contraceptives (requiring non-oral or backup contraception for 4 weeks after initiation and each dose escalation), risk of hypoglycemia when used with insulin or insulin secretagogues, and risk of acute kidney injury with severe gastrointestinal adverse effects. Zepbound should be discontinued if pregnancy is recognized. Routine calcitonin monitoring or thyroid ultrasound is not recommended, but patients should be counseled about thyroid tumor symptoms.
The FDA approval pathway for Zepbound followed a rigorous evaluation process based on data from the SURMOUNT clinical trial program. The FDA granted approval on November 8, 2023, specifically for chronic weight management in adults with a body mass index (BMI) of 30 kg/m² or greater (obesity), or 27 kg/m² or greater (overweight) with at least one weight-related comorbid condition such as hypertension, type 2 diabetes, or dyslipidemia.
The SURMOUNT clinical trial program enrolled over 5,000 participants across multiple phase 3 studies. SURMOUNT-1, the pivotal trial in adults without diabetes, demonstrated that participants receiving the highest dose (15 mg) achieved an average weight loss of approximately 20.9% of body weight over 72 weeks, compared to 3.1% with placebo. SURMOUNT-2 evaluated tirzepatide in adults with obesity and type 2 diabetes, showing significant weight reduction alongside improvements in glycemic control. These robust efficacy data, combined with acceptable safety profiles, formed the basis for FDA review.
The FDA's evaluation included assessment of manufacturing quality, clinical efficacy, and safety data. Reviewers examined cardiovascular safety signals, gastrointestinal tolerability, and potential endocrine effects. The FDA also mandated post-marketing studies to further evaluate safety in real-world populations.
Zepbound's approval represented a significant milestone in obesity pharmacotherapy, offering a new mechanism of action with substantial weight loss efficacy compared to many existing options. The FDA's decision reflected growing recognition of obesity as a chronic disease requiring medical intervention beyond lifestyle modification alone.
Zepbound is available only by prescription from a licensed healthcare provider and cannot be obtained over the counter. Patients interested in Zepbound should consult with their primary care physician, endocrinologist, or obesity medicine specialist to determine if the medication is appropriate for their individual circumstances. The prescribing decision should be based on a comprehensive evaluation including BMI calculation, assessment of weight-related comorbidities, previous weight loss attempts, and screening for contraindications.
Before prescribing Zepbound, clinicians should obtain a thorough medical history, including any personal or family history of medullary thyroid carcinoma, Multiple Endocrine Neoplasia syndrome type 2, or serious hypersensitivity to tirzepatide. Baseline laboratory investigations may include lipid panel, hemoglobin A1c, and liver function tests, depending on the patient's comorbidity profile. Pregnancy testing should be considered for women of childbearing potential. Patients should be counseled on the importance of combining Zepbound with lifestyle modifications, including a reduced-calorie diet and increased physical activity.
Zepbound is distributed through specialty pharmacies and some retail pharmacies in the United States. Insurance coverage varies significantly among plans, and many insurers require prior authorization demonstrating medical necessity, documented BMI criteria, and evidence of previous weight loss attempts. Out-of-pocket costs can be substantial, with list prices exceeding $1,000 per month, though Eli Lilly offers a savings card program that may reduce costs for eligible commercially insured patients. Medicare Part D generally excludes coverage for weight loss medications, and Zepbound currently does not have a covered cardiovascular risk reduction indication.
Supply constraints have periodically affected Zepbound availability since launch, related to high demand and manufacturing capacity. The FDA maintains a drug shortage database that provides current information on availability. Patients should be advised to seek immediate medical attention for severe abdominal pain (possible pancreatitis or gallbladder disease), persistent vomiting/dehydration (risk of acute kidney injury), neck mass/hoarseness/dysphagia (potential thyroid issues), allergic reactions, or symptomatic hypoglycemia (especially if taking insulin or insulin secretagogues). Patients should never purchase tirzepatide from unregulated online sources, as counterfeit products pose serious safety risks. All Zepbound prescriptions should be filled through legitimate US-licensed pharmacies to ensure product authenticity and proper storage conditions.
Yes, Zepbound and Mounjaro contain the same active ingredient, tirzepatide, but are marketed for different FDA-approved indications. Mounjaro is approved for type 2 diabetes management, while Zepbound is specifically indicated for chronic weight management in adults with obesity or overweight with weight-related comorbidities.
Eli Lilly conducted years of preclinical research and clinical trials before receiving FDA approval for tirzepatide as Mounjaro in May 2022, followed by Zepbound approval in November 2023. The SURMOUNT clinical trial program enrolled over 5,000 participants across multiple phase 3 studies to demonstrate safety and efficacy for weight management.
Eli Lilly offers a savings card program that may reduce out-of-pocket costs for eligible commercially insured patients, though coverage varies significantly among insurance plans. Many insurers require prior authorization with documented BMI criteria and evidence of previous weight loss attempts, and Medicare Part D generally excludes coverage for weight loss medications.
All medical content on this blog is created using reputable, evidence-based sources and is regularly reviewed for accuracy and relevance. While we strive to keep our content current with the latest research and clinical guidelines, it is intended for general informational purposes only.
This content is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a licensed healthcare provider with any medical questions or concerns. Use of this information is at your own risk, and we are not liable for any outcomes resulting from its use.
