GLP-1 medications have completely changed what is possible in weight management. In the past five years, these drugs have moved from diabetes clinics to mainstream medicine and for good reason. Clinical trials show weight loss of 15 to 22 percent of body weight, numbers that were previously only achievable with bariatric surgery.
But the landscape is confusing. Ozempic, Wegovy, Mounjaro, Zepbound, Saxenda the names blur together. Some are the same drug in different doses. Some are approved for weight loss; others are technically diabetes medications. And with dozens of online telehealth companies now prescribing compounded versions, knowing which option is legitimate, safe, and right for you has never been more important.
This guide cuts through the noise. We cover every major GLP-1 drug currently available, how they work, how they compare, who is a good candidate, and — critically — what makes the difference between dramatic results and disappointing ones.
What Are GLP-1 Drugs and How Do They Work?
GLP-1 stands for glucagon-like peptide-1, a hormone your body naturally produces in the gut after you eat. It plays several important roles in how your body manages energy:
- It signals your pancreas to release insulin when blood sugar rises
- It slows the rate at which food leaves your stomach, making you feel full longer
- It acts on the brain’s hunger centers to reduce appetite and food cravings
- It lowers glucagon, a hormone that triggers the liver to release stored sugar
GLP-1 receptor agonists are medications that mimic and amplify these effects. By binding to GLP-1 receptors throughout the body, they produce a powerful, sustained version of what your natural hormone does — but for hours or days at a time rather than minutes.
The result is a significant reduction in hunger, a feeling of fullness after smaller meals, and fewer cravings — particularly for high-calorie, highly palatable foods. Over weeks and months, this naturally leads to a meaningful calorie deficit without the psychological suffering of traditional dieting.
| Why this matters for long-term success: Traditional diets fight against your biology — hunger hormones rise and metabolism slows as you restrict calories. GLP-1 medications work with your biology, reducing the hormonal drive to overeat that makes sustained weight loss so difficult through willpower alone. |
All Major GLP-1 Drugs at a Glance
Here is a side-by-side comparison of the most widely used GLP-1 and GLP-1/GIP drugs currently available in the United States:
| Drug Name | Generic Name | Type | FDA Approved | Avg Weight Loss |
| Ozempic / Wegovy | Semaglutide | GLP-1 | Yes | Up to 15% |
| Mounjaro / Zepbound | Tirzepatide | GLP-1 + GIP | Yes | Up to 22.5% |
| Saxenda | Liraglutide | GLP-1 | Yes | Up to 8% |
| Trulicity | Dulaglutide | GLP-1 | Yes (diabetes) | Moderate |
| Victoza | Liraglutide | GLP-1 | Yes (diabetes) | Moderate |
Note: Average weight loss figures are from landmark clinical trials and represent outcomes achieved with lifestyle support. Individual results vary. Tirzepatide’s superior results reflect its dual GLP-1 and GIP mechanism.
Semaglutide (Ozempic / Wegovy): The Gold Standard GLP-1
Semaglutide is the most widely used GLP-1 medication for weight loss and the one most people have heard of, largely because of Ozempic’s high-profile advertising and celebrity associations.
It is important to understand that Ozempic and Wegovy contain the same active ingredient — semaglutide — but are different products. Ozempic is FDA-approved for type 2 diabetes management. Wegovy is FDA-approved specifically for chronic weight management at a higher dose (2.4 mg versus Ozempic’s 1 mg maximum).
Read More :- High Protein Diet for Weight Loss: A Complete Beginner’s Guide
Clinical results:
The STEP clinical trial program, which enrolled over 4,500 adults with obesity, showed that participants taking semaglutide 2.4 mg lost an average of 14.9 percent of their body weight over 68 weeks. Nearly one-third of participants lost more than 20 percent of their body weight.
| ✓ Pros • FDA-approved specifically for weight loss (Wegovy) • Extensive clinical trial data • Weekly injection — convenient dosing • Proven cardiovascular benefits • Available at LeanMD under physician supervision | ✗ Cons • Nausea and GI side effects are common, especially early • Can cause muscle loss without proper protein support • Cost is high without insurance coverage • Supply shortages have affected availability |
Tirzepatide (Mounjaro / Zepbound): The Most Powerful Option
Tirzepatide represents the next generation of weight loss medication. Unlike semaglutide, which targets only GLP-1 receptors, tirzepatide is a dual agonist — it activates both GLP-1 and GIP (glucose-dependent insulinotropic polypeptide) receptors simultaneously.
GIP is another gut hormone involved in insulin secretion and fat metabolism. By hitting both pathways at once, tirzepatide produces a more powerful and synergistic effect on appetite suppression and metabolic regulation.
Clinical results:
The SURMOUNT-1 trial, published in the New England Journal of Medicine, showed tirzepatide produced average weight loss of 20.9 percent at the 15 mg dose. At the highest dose, 57 percent of participants lost at least 20 percent of their body weight — results that rival surgical outcomes.
Mounjaro is FDA-approved for type 2 diabetes. Zepbound is the same medication approved specifically for chronic weight management in adults with obesity or overweight with a weight-related condition.
| ✓ Pros • Highest weight loss efficacy of any approved medication • FDA-approved for weight management (Zepbound) • Dual mechanism provides superior metabolic benefits • Weekly injection • May improve blood sugar, blood pressure, and lipids | ✗ Cons • Newer — less long-term safety data than semaglutide • GI side effects similar to semaglutide • Higher cost than semaglutide • Requires physician oversight to use safely |
Liraglutide (Saxenda): The Original Weight Loss GLP-1
Liraglutide was the first GLP-1 receptor agonist to receive FDA approval specifically for chronic weight management, doing so in 2014 under the brand name Saxenda. It requires daily injections rather than weekly, which has reduced its use as semaglutide and tirzepatide have become available.
Clinical trials show average weight loss of approximately 5 to 8 percent of body weight — meaningful, but significantly less than newer agents. Saxenda remains a reasonable option for patients who cannot access or tolerate semaglutide, and it has the longest safety track record in the weight management space.
| ✓ Pros • FDA-approved for weight loss • Longest safety record among weight loss GLP-1s • Well-studied in patients with cardiovascular disease • Available as a pediatric option (age 12+) | ✗ Cons • Daily injection is less convenient than weekly options • Lower efficacy than semaglutide or tirzepatide • Similar GI side effect profile • Being phased out in favor of newer agents |
What About Compounded Semaglutide and Tirzepatide?
During the Ozempic and Wegovy shortages of 2023 and 2024, compounding pharmacies began producing their own versions of semaglutide and tirzepatide. These became widely available through telehealth companies at significantly lower prices.
It is critical to understand the difference between compounded and brand-name GLP-1 medications:
- Brand-name medications (Wegovy, Zepbound) are FDA-approved, manufactured under strict quality controls, and have been tested in large-scale clinical trials
- Compounded versions are not FDA-approved, meaning they have not undergone the same safety and efficacy testing
- In 2025, the FDA declared the shortage over, meaning compounding of semaglutide and tirzepatide is no longer legally permitted for most pharmacies
- Some compounded products have used different salt forms of semaglutide (such as semaglutide acetate instead of semaglutide sodium) that have not been shown to behave identically in the body
| LeanMD’s position on compounded GLP-1s: LeanMD prescribes only FDA-approved medications from licensed pharmacies. Our physicians will never recommend a treatment they would not be comfortable prescribing to a family member. Patient safety is not negotiable. |
Who Is a Good Candidate for GLP-1 Weight Loss Medication?
GLP-1 medications are not appropriate for everyone. In the United States, FDA guidelines indicate these medications for:
- Adults with a BMI of 30 or higher (obesity)
- Adults with a BMI of 27 or higher who also have at least one weight-related health condition, such as type 2 diabetes, high blood pressure, high cholesterol, or obstructive sleep apnea
You should discuss GLP-1 medications with a physician if you have any of the following, as they may affect which medication is appropriate or require additional monitoring:
- Personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2 (MEN2) — a contraindication for all GLP-1 drugs
- History of pancreatitis
- Kidney disease or a history of gallstones
- Pregnancy or plans to become pregnant
- History of eating disorders
The Critical Factor Most People Overlook: Muscle Loss
Here is something that rarely appears in GLP-1 marketing: these medications can cause significant muscle loss alongside fat loss, particularly at the aggressive weight loss rates they enable.
Research from the SURMOUNT and STEP trials showed that up to 40 percent of the weight lost on GLP-1 medications can come from lean mass (muscle), not fat. This is a serious problem for several reasons:
- Muscle loss slows your resting metabolic rate, making it harder to keep weight off after stopping the medication
- Reduced muscle mass increases the risk of falls, fractures, and loss of physical function — particularly in older adults
- The ‘skinny fat’ phenomenon — normal BMI but high body fat percentage — is a real outcome of poorly managed GLP-1 use
The solution is not to avoid GLP-1 medications. It is to use them correctly — with adequate protein intake (typically 1.2 to 1.6 grams per kilogram of body weight per day) and a structured resistance exercise program. This is exactly why physician supervision and personalized nutritional guidance are not optional add-ons. They are essential to getting good outcomes.
Ready to Start GLP-1 Therapy the Right Way?
LeanMD’s California-based physicians evaluate each patient individually, prescribe only FDA-approved medications, and provide the nutritional and lifestyle support that makes GLP-1 therapy truly effective — not just temporarily.
Find a LeanMD Physician Near You →How to Get GLP-1 Medication Prescribed Safely
With the rise of telehealth weight loss companies, obtaining a GLP-1 prescription has become easier — but easier is not always better. The most important thing you can do is work with a physician who evaluates your full medical picture before prescribing.
A proper GLP-1 evaluation should include:
- A complete medical history and review of current medications
- BMI and body composition assessment
- Blood work including metabolic panel, HbA1c, lipid panel, and thyroid function
- Cardiovascular risk assessment
- Discussion of realistic expectations, side effect management, and a plan for nutritional support
Be cautious of any service that prescribes GLP-1 medications after a brief online questionnaire with no physician review. These medications are powerful metabolic agents. Used correctly with proper supervision, they can be life-changing. Used carelessly, they carry real risks.
Read More :- Why You’re Not Losing Weight Despite Dieting
The Bottom Line: Which GLP-1 Drug Is Best for Weight Loss?
Based on current clinical evidence, tirzepatide (Zepbound) produces the highest average weight loss, followed by semaglutide (Wegovy), and then liraglutide (Saxenda). However, the ‘best’ drug is always the one that is right for your individual health profile, medical history, and goals — not the one with the highest headline number.
What matters far more than which medication you choose is how you use it. Physician supervision, personalized nutrition with adequate protein, and a structured approach to preserving muscle mass are what separate patients who achieve lasting transformation from those who lose weight temporarily and regain it.
| Interested in GLP-1 therapy at LeanMD? Our California-based physicians evaluate each patient individually, prescribe only FDA-approved medications, and provide the nutritional and lifestyle support that makes GLP-1 therapy truly effective — not just temporarily. Visit leanmd.com to find a LeanMD physician near you. |
Frequently Asked Questions
What is the difference between Ozempic and Wegovy?
Both contain semaglutide, but they are different products. Ozempic is FDA-approved for type 2 diabetes management, with a maximum dose of 1 mg per week. Wegovy is FDA-approved specifically for chronic weight management at a higher dose of 2.4 mg per week. Wegovy typically produces greater weight loss because of the higher dose.
Can I get GLP-1 drugs for weight loss if I don’t have diabetes?
Yes. Wegovy (semaglutide) and Zepbound (tirzepatide) are both FDA-approved for weight management in adults with obesity or overweight with a weight-related health condition, regardless of whether diabetes is present. You do not need to have diabetes to qualify.
How long do you have to take GLP-1 medication?
GLP-1 medications are currently considered long-term treatments. Studies show that when people stop taking them, a significant portion of the weight typically returns within 12 months. The goal of a well-structured program is to use the medication period to build sustainable habits — in nutrition, activity, and lifestyle — that support weight maintenance afterward.
What happens if I stop taking GLP-1 medication?
Most people experience some weight regain after stopping GLP-1 medications, as hunger hormones return to pre-treatment levels. The degree of regain depends heavily on what habits were established during the treatment period. Patients who built strong protein-focused nutrition habits and a consistent exercise routine tend to maintain significantly more of their weight loss than those who relied on the medication alone.
Are GLP-1 drugs safe long-term?
Semaglutide has the longest safety record, with data now extending beyond five years in the cardiovascular outcomes trials. Tirzepatide’s long-term data is still accumulating but the profile looks favorable. The most significant long-term concern is muscle loss with rapid weight loss, which is why proper nutritional support throughout treatment is essential. All GLP-1 prescriptions at LeanMD include physician monitoring for this reason.
Is tirzepatide better than semaglutide for weight loss?
In head-to-head comparisons, tirzepatide has consistently shown greater average weight loss than semaglutide. The SURMOUNT-5 trial directly compared the two medications and found tirzepatide produced approximately 20 percent weight loss compared to 14 percent for semaglutide. However, tirzepatide is newer and individual responses vary. Your physician is best positioned to recommend which is appropriate for your specific situation.
Medical Disclaimer
This article is for informational purposes only and does not constitute medical advice. GLP-1 medications require a prescription and physician evaluation. Results vary by individual. Always consult a qualified healthcare provider before starting any weight loss medication.