Top Research Supporting Semaglutide & Tirzepatide for Weight Loss
Below are 10 high-quality, peer-reviewed studies with short summaries
Semaglutide (GLP-1) Research
1. Wilding et al., 2021 – NEJM (STEP-1 Trial)
Finding: Adults with overweight/obesity (without diabetes) lost an average of 14.9% of body weight at 68 weeks.
Citation: Wilding JPH, et al. N Engl J Med. 2021;384:989–1002.
2. Davies et al., 2021 – STEP-2 Trial (T2D Population)
Finding: Adults with type 2 diabetes lost 9.6% body weight on semaglutide 2.4 mg vs 3.4% with placebo.
Citation: Davies M, et al. Diabetes Care. 2021;44(4):950–960.
3. Wadden et al., 2021 – STEP-3 Trial (Intensive Behavioral Therapy)
Finding: Combining semaglutide with behavioral therapy produced ~16% mean weight loss at 68 weeks.
Citation: Wadden TA, et al. JAMA. 2021;325(14):1403–1413.
4. Rubino et al., 2021 – STEP-4 Trial (Withdrawal Study)
Finding: Continued semaglutide maintained weight loss; stopping the medication led to significant regain.
Citation: Rubino D, et al. JAMA. 2021;325(14):1414–1425.
5. SELECT Trial, 2023–2024 (Cardiovascular Outcomes Study)
Finding: Semaglutide 2.4 mg reduced major cardiovascular events by 20% and produced 9–12% sustained weight loss over 3 years.
Citation: SELECT Investigators. N Engl J Med. 2023;389:2221–2232.
Tirzepatide (Dual GLP-1/GIP) Research
6. Jastreboff et al., 2022 – NEJM (SURMOUNT-1 Trial)
Finding: Adults without diabetes lost 15–20.9% of body weight at 72 weeks depending on dose.
Citation: Jastreboff AM, et al. N Engl J Med. 2022;387:205–216.
7. Ludvik et al., 2021 – SURPASS-1 (T2D Population)
Finding: Tirzepatide produced 5.4–8.8 kg weight loss in type 2 diabetes patients over 40 weeks.
Citation: Ludvik B, et al. Lancet. 2021;398:143–155.
8. SURMOUNT-2 (2023) – Tirzepatide in T2D + Obesity
Finding: Produced ~14.7% weight loss in adults with obesity and type 2 diabetes at 72 weeks.
Citation: Frias JP, et al. Lancet. 2023;402:123–133.
9. SURMOUNT-3 (2023) – Lifestyle Intervention + Tirzepatide
Finding: After a lifestyle-run-in phase, tirzepatide added a further 18.4% weight loss beyond diet/exercise alone.
Citation: Garvey WT, et al. JAMA. 2023;330(16):1471–1481.
10. SURMOUNT-4 (2024) – Maintenance After Weight Loss
Finding: Continuing tirzepatide maintained up to 25% total weight loss, while stopping it led to ~14% regain.
Citation: Aronne LJ, et al. JAMA. 2024;331(6):496-506.
What this research means for you….
These medications are backed by large, high-quality clinical trials.
Most patients lose 10–20% of their body weight,often more with Tirzepatide.
Benefits last as long as treatment continues.
They also improve blood sugar, inflammation, blood pressure, and cardiovascular health.