Tirzepatide: Research Applications

🧠 Type 2 Diabetes (SURPASS Program)

Tirzepatide has been studied across the SURPASS clinical trial program (SURPASS-1 through SURPASS-6, plus SURPASS-CVOT) in over 17,000 study subjects with type 2 diabetes mellitus (T2DM). In SURPASS-2 (n=1,879), tirzepatide demonstrated superiority over semaglutide 1 mg, with HbA1c reductions of −2.01% to −2.30% vs. −1.86%, and weight loss of −7.6 to −11.2 kg vs. −5.7 kg. [7] The landmark SURPASS-CVOT (n=13,299) confirmed cardiovascular tolerability with a MACE HR of 0.92 vs. dulaglutide. [20]

⚖️ Obesity & Weight Management (SURMOUNT Program)

In the pivotal SURMOUNT-1 trial (n=2,539 adults with obesity, without T2DM), tirzepatide produced weight reductions of −15.0% (5 mg), −19.5% (10 mg), and −20.9% (15 mg) at 72 weeks vs. −3.1% with placebo. [21] The 3-year SURMOUNT-1 extension showed sustained weight reduction (−12.3% to −19.7%) and a 94% reduction in risk of progression to T2D (HR 0.07). [22]

In the head-to-head SURMOUNT-5 trial (n=751), tirzepatide achieved −20.2% weight loss vs. −13.7% for semaglutide 2.4 mg, establishing superiority. [23]

See also: AOD-9604 for related weight management research.

❤️ Heart Failure (SUMMIT Trial)

The SUMMIT trial (n=731) investigated tirzepatide in study subjects with heart failure with preserved ejection fraction (HFpEF) and obesity, showing a 38% reduction in risk of CV death/worsening heart failure (HR 0.62) and 6.9-point greater improvement in KCCQ-CSS (Kansas City Cardiomyopathy Questionnaire). [24]

💤 Obstructive Sleep Apnea (SURMOUNT-OSA)

The SURMOUNT-OSA trials (n=469) demonstrated that tirzepatide reduced the apnea-hypopnea index (AHI) by up to 62.8% (−25.3 to −29.3 events/hr vs. −5.3 to −5.5 placebo) in study subjects with moderate-to-severe OSA and obesity. The FDA-registered Zepbound for OSA in December 2024. [25]

🫁 Liver Disease (SYNERGY-NASH)

In the Phase 2 SYNERGY-NASH trial (n=190), tirzepatide achieved MASH resolution without worsening fibrosis in 44% (5 mg), 56% (10 mg), and 62% (15 mg) vs. 10% placebo. Fibrosis improvement (≥1 stage) occurred in ~51–55% of tirzepatide groups vs. 30% placebo. [17]

🧠 Neuroprotection (Preclinical)

Preclinical studies suggest tirzepatide may have neuroprotective effects in Alzheimer’s and Parkinson’s disease models. In APP/PS1 mice (Alzheimer’s model), tirzepatide reduced amyloid-beta plaque density, decreased astrocytic activation, and reduced neuronal ROS production. [26] In neuroblastoma cells, it prevented high-glucose-induced neurodegeneration via CREB/BDNF pathway modulation. [13]

🫀 Kidney Protection (Exploratory)

Exploratory analyses from SURPASS-4 indicate tirzepatide may delay eGFR decline and reduce albuminuria compared to insulin glargine, prompting ongoing studies targeting chronic kidney disease outcomes. [27]