# Tirzepatide: The Dual GIP/GLP-1 Cardiometabolic Trial Record > Tirzepatide is an FDA-approved dual GIP/GLP-1 receptor agonist. SURPASS: -2.30 HbA1c percentage points. SURMOUNT-1: -20.9% body weight. MACE-4 HR 0.80. Every figure cited. SURPASS, SURMOUNT, SUMMIT, SURPASS-CVOT — an independent reading of what the trials measured, every figure traced to its published source. ## The short version Tirzepatide is a prescription drug approved by the FDA for type 2 diabetes (May 2022), chronic weight management (November 2023), and moderate-to-severe obstructive sleep apnea in adults with obesity. It is a synthetic peptide — a chain of 39 amino acids — that works by mimicking two gut hormones your body naturally releases after eating: GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1). Both hormones tell the pancreas to release insulin, and GLP-1 also curbs appetite and slows how fast food leaves the stomach. By engaging both pathways at once, tirzepatide produces bigger drops in blood sugar and body weight than older drugs that only hit GLP-1 alone. In large clinical trials, participants with obesity lost up to 20.9% of their body weight over 72 weeks. In head-to-head comparisons it outperformed the leading GLP-1-only drug on both blood sugar and weight. The most common side effects are nausea, vomiting, diarrhea, and constipation — mostly during dose escalation. What people report — including the downsides — is on [the effects page](/effects). ## Cardiometabolic outcomes: what the record shows Tirzepatide holds the largest cardiometabolic trial record of any dual incretin agent. Across the SURPASS programme in type 2 diabetes, once-weekly doses of 5, 10, and 15 mg reduced glycated haemoglobin (HbA1c — the standard blood-sugar average marker) by 2.01, 2.24, and 2.30 percentage points respectively, versus 1.86 percentage points with a selective GLP-1 receptor agonist at standard dose — tirzepatide was non-inferior and superior at all three doses [1]. A pre-specified meta-analysis of all seven SURPASS trials (4,887 tirzepatide participants versus 2,328 controls) produced a MACE-4 (major adverse cardiovascular event) hazard ratio of 0.80 (95% CI 0.57-1.11), with cardiovascular death HR 0.90 and all-cause death HR 0.80 — tirzepatide did not increase cardiovascular risk versus controls, with point estimates consistently favouring tirzepatide [2]. The lipid profile is also improved. Across 14 articles from 13 randomised controlled trials, tirzepatide significantly improved all lipid markers — total cholesterol, LDL, HDL, and triglycerides — with a dose-response trend across the 5, 10, and 15 mg doses [3]. In the SUMMIT trial in adults with heart failure with preserved ejection fraction (HFpEF) and obesity, tirzepatide reduced heart-failure events and improved functional status [4]. SURPASS-CVOT, the dedicated cardiovascular outcomes trial versus an established GLP-1 receptor agonist, reported its primary endpoint in 2025 [5]. For [Tirzepatide research](/research), mechanism, and full trial summaries, see the research page. ## Tirzepatide results across the SURMOUNT programme Tirzepatide results in the SURMOUNT programme are among the largest weight-loss figures in the modern trial record. SURMOUNT-1 enrolled 2,539 adults with obesity (BMI ≥30, or ≥27 with a weight-related complication) and without diabetes. Over 72 weeks, mean body-weight change was -15.0% (5 mg), -19.5% (10 mg), and -20.9% (15 mg) versus -3.1% with placebo [6]. In SURMOUNT-5 — a head-to-head against the leading GLP-1-only agent in a 72-week open-label trial of 751 adults with obesity without diabetes — tirzepatide produced -20.2% body weight versus -13.7% (p<0.001) [7]. Weight reduction was accompanied by greater reductions in waist circumference and higher proportions reaching ≥10%, ≥15%, ≥20%, and ≥25% weight loss thresholds [7]. [Tirzepatide weight loss](/weight-loss) data by trial and dose are on the dedicated page. Weight reduction occurs independently of gastrointestinal adverse events: a post-hoc analysis of SURPASS participants confirmed that weight loss was not solely attributable to GI side effects [8]. ## Tirzepatide peptide: structure and approval status Tirzepatide peptide is a linear 39-amino-acid synthetic molecule engineered from the native GIP backbone. It carries a C20 fatty diacid (eicosanedioic acid) attached via a glutamic-acid linker and two short chemical spacers to a lysine side chain — the fatty-diacid arm binds tightly to albumin in the bloodstream, extending the elimination half-life to approximately 5 days and enabling once-weekly subcutaneous dosing [9]. Molecular weight: 4813.53 Da. ATC code: A10BX16. CAS number: 2023788-19-2. Approval sequence: FDA approved for type 2 diabetes (May 2022) [9], chronic weight management in adults with obesity or overweight plus a weight-related condition (November 2023), and subsequently for moderate-to-severe obstructive sleep apnea in adults with obesity. In vitro signalling work confirmed it is an imbalanced dual agonist, engaging the GIP receptor more fully than the GLP-1 receptor, and showing biased GLP-1 receptor signalling that favours cAMP generation over beta-arrestin recruitment — a pharmacological profile proposed to enhance insulin secretion beyond what either single-receptor pathway produces alone [10]. [What is tirzepatide](/what-is-tirzepatide) covers the mechanism in depth. ## Tirzepatide reviews: trial findings and the community record Tirzepatide reviews in the clinical literature consistently reproduce the large HbA1c and weight reductions documented across the SURPASS and SURMOUNT trials. At the monotherapy level, SURPASS-1 substudy analysis found improvements in markers of beta-cell function and insulin sensitivity independent of background diabetes medications [11]. The SURPASS-5 trial in type 2 diabetes inadequately controlled on insulin glargine found that adding once-weekly tirzepatide significantly improved glycaemic control and reduced body weight versus placebo [12]. Beyond efficacy, the community record includes reports of dramatically reduced appetite and food cravings, improved energy, better sleep, and in some cases reduced joint pain — these are anecdotal signals from patient communities, not clinical findings, and are covered on [Tirzepatide effects](/effects) with the mandatory anecdotal label. The safety profile — dominated by GI side effects during dose escalation, with well-characterised signals for gallbladder events and a label-directed boxed warning for thyroid C-cell tumours — is set out on the same page. --- Trial figures, mechanism notes, and safety signals — tabulated from the published literature, with no clinical role held.