A 2026 cost-effectiveness analysis found that semaglutide 2.4 mg combined with diet and exercise costs €25,589 per year of healthy life gained in Spain, making it cost-effective under the healthcare system’s €30,000 threshold. According to Gram Research analysis, the injection helped people gain an extra 0.1049 quality-adjusted life years over 40 years compared to diet and exercise alone, with an additional cost of only €2,685 per person over that period.
A new study shows that semaglutide, a once-weekly injection that helps people lose weight, is worth the cost for Spain’s healthcare system. Researchers used computer models to predict what would happen over 40 years if people with obesity used semaglutide along with diet and exercise, compared to just diet and exercise alone. The shot helped people lose more weight and stay healthier longer, and the health benefits were worth the extra €2,685 cost per person over 40 years. This research suggests that semaglutide could be a smart investment for helping people manage their weight and avoid serious health problems.
Key Statistics
A 2026 cost-effectiveness analysis in Spain found that semaglutide 2.4 mg combined with diet and exercise costs €25,589 per quality-adjusted life year gained, falling below Spain’s €30,000 cost-effectiveness threshold.
According to research reviewed by Gram, semaglutide 2.4 mg provided an additional 0.1049 quality-adjusted life years over 40 years with only €2,685 in extra costs per person compared to diet and exercise alone.
A 2026 Spanish healthcare analysis based on the STEP 1 trial data showed that semaglutide combined with lifestyle changes remained cost-effective across multiple sensitivity analyses testing different assumptions about drug efficacy and costs.
The Quick Take
- What they studied: Whether adding a weekly semaglutide injection to diet and exercise is worth the cost compared to diet and exercise alone for treating obesity in Spain
- Who participated: The study used data from a previous trial called STEP 1, which included adults averaging 46 years old with obesity (BMI of 30 or higher). The computer model then projected results for 40 years into the future
- Key finding: Semaglutide combined with diet and exercise cost €25,589 per year of healthy life gained, which is below Spain’s acceptable cost threshold of €30,000 per year of healthy life
- What it means for you: If you have obesity in Spain, semaglutide might be a cost-effective option worth discussing with your doctor, though it works best when combined with diet and exercise changes. Individual results vary, and this doesn’t guarantee insurance coverage
The Research Details
This wasn’t a traditional experiment with people in a lab. Instead, researchers used a computer model called the Core Obesity Model to predict what would happen to people with obesity over 40 years. They plugged in real data from a previous study (STEP 1) that tested semaglutide in about 1,961 adults, measuring how much weight people lost and how their blood pressure and blood sugar changed.
The model compared two groups: one that got semaglutide plus diet and exercise, and another that only did diet and exercise. The researchers then calculated how much it would cost Spain’s healthcare system and how many extra healthy years people would gain. They looked at direct medical costs only—things like doctor visits, medications, and hospital stays—not indirect costs like lost work time.
To make sure their results were reliable, the researchers tested what would happen if they changed their assumptions slightly. This is called sensitivity analysis, and it helps confirm that the main findings don’t depend on one lucky guess.
Using computer models to predict long-term health outcomes is important because we can’t wait 40 years to see real results. This approach lets healthcare systems decide whether expensive new treatments are worth the investment by looking at the total cost compared to the total health benefit. For obesity treatment, this matters because the disease causes many expensive health problems over time, like heart disease and diabetes
This study is based on real trial data (STEP 1), which is a strength. However, the study uses predictions rather than actual patient outcomes, so real-world results might differ. The researchers tested their assumptions to check robustness, which is good practice. The study was done specifically for Spain’s healthcare system, so results might not apply exactly to other countries with different healthcare costs
What the Results Show
Over 40 years, adding semaglutide to diet and exercise gave people an extra 0.1049 quality-adjusted life years (QALYs) compared to diet and exercise alone. A QALY is a way of measuring both how long someone lives and how good their health is during that time. The extra cost was €2,685 per person over 40 years, which works out to €25,589 for each additional year of healthy life gained.
Spain’s healthcare system considers a treatment cost-effective if it costs less than €30,000 per QALY gained. Since semaglutide came in at €25,589, it passed this test. The researchers also ran multiple sensitivity analyses—basically testing what happens if they change their assumptions—and the results stayed consistent. This means the finding is probably reliable even if some of the numbers shift slightly.
The model showed that semaglutide’s benefits came from helping people lose weight, which then prevented or delayed serious health problems like heart disease, stroke, and type 2 diabetes. These are expensive conditions to treat, so preventing them saves the healthcare system money in the long run, even though the semaglutide injection costs money upfront.
The study found that semaglutide’s cost-effectiveness held up even when researchers changed their assumptions about how long the weight loss would last, how much the drug would cost, or how much benefit it would provide. This suggests the finding is solid across different scenarios. The model also showed that the longer people used semaglutide, the more money the healthcare system saved overall, because preventing diseases is cheaper than treating them
This is one of the first studies looking at whether semaglutide is cost-effective specifically in Spain. Similar studies in other countries have found semaglutide to be cost-effective, but healthcare costs and thresholds vary by country. This Spanish analysis adds important evidence that the drug’s benefits justify its cost in the Spanish healthcare context
The biggest limitation is that this study uses predictions, not real patient data over 40 years. The model is based on the STEP 1 trial, which tested semaglutide in a specific group of people—mostly middle-aged adults with obesity. Results might be different for younger people, older people, or people with other health conditions. The study only counted direct healthcare costs, not other expenses like patient time or lost work productivity. Finally, the study assumes people will keep using semaglutide as prescribed for many years, which might not happen in real life
The Bottom Line
According to Gram Research analysis, semaglutide 2.4 mg combined with diet and exercise appears to be a cost-effective treatment option for obesity in Spain (strong evidence from economic modeling). It should be considered as part of a comprehensive weight management plan that includes dietary changes and physical activity, not as a replacement for them (moderate confidence). Discuss with your doctor whether this option is appropriate for your specific situation (standard recommendation)
This research is most relevant for: adults with obesity in Spain considering weight loss treatments, healthcare providers deciding which obesity treatments to recommend, and Spanish healthcare policymakers allocating resources. It’s less relevant for people in other countries with different healthcare systems and costs, though the general principles may apply. People with certain medical conditions or taking certain medications should consult their doctor before considering semaglutide
Based on the STEP 1 trial data, most weight loss happens in the first 6-12 months of using semaglutide. However, the main health benefits—like preventing heart disease and diabetes—develop over years and decades. You shouldn’t expect to see all the benefits this study describes in a few months; the real value comes from long-term use
Frequently Asked Questions
Is semaglutide worth the cost for weight loss in Spain?
Yes, according to 2026 research, semaglutide costs €25,589 per year of healthy life gained in Spain, which is below the €30,000 threshold considered cost-effective by the Spanish healthcare system. It works best combined with diet and exercise.
How much weight do people lose with semaglutide injections?
The STEP 1 trial data used in this analysis showed significant weight loss, though specific percentages weren’t detailed in the cost-effectiveness study. Results vary by individual, and weight loss requires combining the injection with reduced-calorie diet and regular exercise.
How long does it take to see health benefits from semaglutide?
Most weight loss occurs within 6-12 months of starting semaglutide. However, the major health benefits—like preventing heart disease and diabetes—develop over years and decades of consistent use combined with lifestyle changes.
Can semaglutide replace diet and exercise for weight loss?
No. This research shows semaglutide works as an adjunct to diet and exercise, not a replacement. The injection is approved specifically for use alongside reduced-calorie eating and increased physical activity, not as a standalone treatment.
Who should consider using semaglutide for weight loss?
Adults with obesity (BMI of 30 or higher) in Spain may benefit from discussing semaglutide with their doctor. The research is based on middle-aged adults, so effectiveness and safety in other age groups may differ. Individual medical history matters significantly.
Want to Apply This Research?
- Track weekly weight, waist circumference, and energy levels. Set a goal to lose 5-10% of body weight over 6 months, then measure progress monthly. Also track diet adherence (meals with reduced calories) and exercise minutes per week
- Use the app to log daily meals to maintain the reduced-calorie diet that semaglutide requires to work effectively. Set reminders for your weekly injection day. Track physical activity minutes and set a goal of 150 minutes of moderate exercise per week
- Create a dashboard showing weight trend over time, BMI changes, and achievement of diet/exercise goals. Set monthly check-in reminders to review progress and adjust goals. Track any side effects or concerns to discuss with your healthcare provider at regular appointments
This article summarizes research on semaglutide’s cost-effectiveness in Spain’s healthcare system. It is not medical advice. Semaglutide is a prescription medication that requires a doctor’s evaluation and supervision. Individual results vary based on health status, medications, and lifestyle factors. Do not start, stop, or change any weight loss treatment without consulting your healthcare provider. This research applies specifically to Spain’s healthcare system; costs and coverage may differ in other countries. People with a personal or family history of thyroid cancer, multiple endocrine neoplasia type 2, or certain other conditions should not use semaglutide. Discuss all potential risks and benefits with your doctor before beginning treatment.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.