The U.S. Food and Drug Administration (FDA) approved two new weight loss drugs in 2022 that go beyond diet and exercise.
Called semaglutide and tirzepatide, these once-weekly injections curb appetite while accelerating fat burn.
Early results reveal powerful weight loss compared to placebo across various groups.
Let’s explore how these exciting new FDA-approved weight loss medications support healthy, sustainable shedding of pounds.
How Do Semaglutide and Tirzepatide Aid Weight Loss?
Semaglutide and tirzepatide belong to a class of drugs called glucagon-like peptide-1 (GLP-1) receptor agonists. They mimic a hormone called GLP-1 that targets areas of your brain involved in appetite.
Here are the main ways these new medications spur weight loss:
- Curb Appetite: By activating brain regions that suppress appetite, semaglutide and tirzepatide blunt hunger and appetite. This leads to reduced calorie intake to create a deficit for shedding pounds.
- Slow Digestion: They slow stomach emptying so you feel fuller longer after smaller portions.
- Burn Fat: Beyond appetite suppression, they directly stimulate brown fat to burn more calories while preventing new fat formation.
- Regulate Blood Sugar: Improved glucose control and insulin sensitivity assist weight loss while benefiting overall health.
Together, experts believe these effects underlie the meaningful weight loss produced by semaglutide-based and tirzepatide-based treatments.
Weight Loss Results: What Does the Research Show?
In large clinical trials with thousands of adults who were overweight or had obesity, both medications demonstrated:
- Average 15-25% body weight loss in 68 weeks on the drugs
- 5-15% greater weight loss versus placebo groups on lifestyle changes alone
Participants received counseling on nutrition and fitness. But those also getting weekly semaglutide or tirzepatide injections lost much more weight on average.
| Treatment | Avg. Weight Loss | Placebo Comparison |
| Semaglutide | 15% in 68 weeks | 5% more than placebo over 68 weeks |
| Tirzepatide | 22% in 72 weeks | 15% more than placebo over 72 weeks |
Such impressive results exceeded prior prescription medications for obesity. Makers seek approval for treating diabetes and heart disease next.
Let’s examine the trials and real-world implications of these new therapies…
Semaglutide (Wegovy): Appetite-Suppressing Shot
Approved in 2021 for chronic weight management, semaglutide (Wegovy) produced powerful appetite and weight reduction as add-on to lifestyle interventions across trials.
The main 68-week study compared once-weekly semaglutide injection vs placebo in 1961 people with overweight or obesity. Key findings included:
- 15% weight loss for semaglutide group vs 2.4% for placebo
- 36% achieved ≥15% weight loss with semaglutide vs only 3% with placebo
Gastrointestinal side effects like nausea occurred more often with semaglutide. But overall safety was similar between groups.
Real-world reports also demonstrate semaglutide delivers significant weight loss when combined with nutrition/exercise counseling.
As the first shot for obesity since 2014, semaglutide offers new hope for substantial, durable weight reduction for millions struggling despite diet/lifestyle changes.
Tirzepatide (Mounjaro): Dual Action for Weight Loss
Given in 2021 for treating type 2 diabetes, tirzepatide (Mounjaro) also showed remarkable weight lowering potential across trials.
The 72-week SURMOUNT-1 study compared tirzepatide vs placebo for obesity. Key results were:
- Average 22.5% weight loss for highest tirzepatide dose group
- Up to 52% shed ≥20% body weight with tirzepatide
- 15% greater weight loss than placebo mismatch
As with semaglutide, tirzepatide was fairly well tolerated but linked to more GI issues than placebo.
So beyond improving blood sugar levels, tirzepatide triggers substantial appetite and weight loss too.
Who Is Eligible for New Weight Loss Drugs?
The table below summarizes current FDA approval and eligibility for the medications:
| Drug | Approved Use | Eligibility Criteria |
| Semaglutide | Chronic Weight Management | Adults with BMI ≥30 or ≥27 with weight-related medical problems |
| Tirzepatide | Type 2 Diabetes Treatment | Adults with BMI ≥30 or ≥27 with weight-related medical problems |
So adults who have obesity (BMI ≥30) qualify for both drugs, regardless of diabetes status.
Those who are overweight (BMI 27 to 29) can also receive these shots if having weight-related conditions like high blood pressure or heart disease.
But safety and effectiveness remain under investigation for BMI <27. Talk to your doctor about access, insurance coverage, and suitability for your personal health profile.
The Takeaway: New Medications Trigger Significant Weight Loss
Semaglutide and tirzepatide represent breakthrough once-weekly injections that spur considerable weight loss through suppressing appetite while accelerating calorie burn.
Across key trials, average 15-22% body weight reduction over about one year greatly exceeded placebo and old obesity medications.
When combined with nutrition/fitness counseling, these new FDA-approved weight loss drugs provide powerful assistance for losing pounds.
Discuss your weight history and goals with your healthcare provider. As part of a comprehensive plan, semaglutide or tirzepatide could help you finally achieve healthy, sustainable weight loss.
