Semaglutide 1 Year Results: Full 12-Month Clinical Data
One year on semaglutide represents the point where most patients are approaching or have reached their maximum weight loss. The landmark STEP 1 clinical trial showed average weight loss of 14.9% of body weight at 68 weeks, with some patients losing more than 25%. Here is the complete data picture at the one-year mark.
Medical Disclaimer: This article is for informational purposes only. Individual results vary significantly. Past clinical trial results do not guarantee your personal outcome.
12-Month Weight Loss: STEP Trial Data
| Trial | Duration | Avg. % Lost | Avg. lbs (220 lb start) | Placebo Comparison |
|---|---|---|---|---|
| STEP 1 | 68 weeks | -14.9% | ~33 lbs | -2.4% placebo |
| STEP 2 (T2D) | 68 weeks | -9.6% | ~21 lbs | -3.4% placebo |
| STEP 3 (+ lifestyle) | 68 weeks | -16.0% | ~35 lbs | -5.7% placebo |
| STEP 5 (2 years) | 104 weeks | -15.2% | ~33 lbs | -2.6% placebo |
Results Distribution: Not Everyone Is Average
| Weight Loss Category | % of Patients (STEP 1) | lbs Lost (220 lb start) |
|---|---|---|
| Less than 5% | ~14% | <11 lbs |
| 5-10% | ~20% | 11-22 lbs |
| 10-15% | ~24% | 22-33 lbs |
| 15-20% | ~18% | 33-44 lbs |
| 20%+ | ~32% | 44+ lbs |
Comprehensive Health Outcomes at 1 Year
| Health Marker | Average Change |
|---|---|
| Waist circumference | -5 to -7 inches |
| Systolic blood pressure | -6 to -10 mmHg |
| HbA1c (diabetic patients) | -1.0 to -1.8% |
| Triglycerides | -20 to -30% |
| CRP (inflammation) | -30 to -50% |
| Quality of life score | Significantly improved |
Maintaining Results After Year One
The critical question at 12 months is whether to continue treatment. The STEP 4 trial demonstrated that patients who switched from semaglutide to placebo after 20 weeks regained approximately two-thirds of lost weight within the following year, while those who continued treatment maintained their weight loss. This underscores that semaglutide works best as a long-term treatment for a chronic condition.
- Continuing treatment: Most patients who continue semaglutide maintain their weight loss and may see modest additional loss through month 16-20.
- Dose optimization: Some patients can maintain results on a lower maintenance dose, reducing cost and side effects.
- Lifestyle foundation: Patients who built strong exercise and nutrition habits during treatment have better outcomes if they eventually discontinue.
Frequently Asked Questions
How much weight do you lose in 1 year on semaglutide?
STEP 1 showed average loss of 14.9% at 68 weeks. At 12 months specifically, average loss is approximately 13-15% of starting body weight, or about 29-33 pounds from a 220-pound starting weight.
What percentage of patients lose more than 20% body weight?
Approximately one-third of patients in STEP 1 lost 20% or more. About 10% lost more than 25% of their starting body weight.
Does weight loss continue after 12 months?
For most patients, modest additional weight loss continues through months 12-16 before stabilizing. STEP 5 (2-year data) shows sustained loss of approximately 15.2%.
For long-term treatment with ongoing clinical support, explore Trimi's semaglutide programs.
More on GLP-1 Results & Outcomes
Sources & References
- Wilding JPH et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. NEJM 2021;384:989-1002.
- Jastreboff AM et al. Tirzepatide Once Weekly for the Treatment of Obesity. NEJM 2022;387:205-216.
- Lincoff AM et al. Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes. NEJM 2023;389:2221-2232.
- FDA Prescribing Information for Wegovy (semaglutide) and Zepbound (tirzepatide).