Weight Loss
The Truth About GLP-1s: Benefits, Side Effects, and Real Results
Jun 10, 2025

What Are GLP-1 Agonists and How Do They Work?
GLP-1 (glucagon-like peptide-1) receptor agonists are a class of medications that mimic a natural hormone produced in the gut. This hormone plays a key role in managing appetite and blood sugar levels.
When taken regularly, GLP-1 agonists:
Slow down how quickly your stomach empties, so you feel full longer
Reduce appetite and food cravings
Enhance insulin secretion (helpful for blood sugar control)
Suppress glucagon, a hormone that raises blood sugar levels
Some GLP-1s like semaglutide (found in Ozempic and Wegovy) and tirzepatide (Mounjaro) have been adapted to specifically support weight loss in patients with obesity or overweight with health-related risk factors.
The combination of the actions above make it easier than ever to achieve a calorie deficit and control blood sugar levels, an incredible recipe for losing weight.
What the Studies Say: Evidence on Effectiveness
Clinical studies have consistently shown that GLP-1 drugs lead to substantial weight loss when combined with diet and exercise. For example:
In a 68-week trial of semaglutide (Ozempic/Wegovy), patients lost an average of 15% of their body weight—some even more.
In studies of tirzepatide (Mounjaro/Zepbound), participants lost between 15% and 20% of their weight, depending on the dose.
For context, traditional weight loss interventions (without medication) often result in just 5–10% weight loss, which is still clinically meaningful.
The key takeaway: These drugs can offer a major boost in weight loss, especially for people who have struggled with lifestyle changes alone.
However, results vary based on adherence, dosage, and lifestyle. In nearly all studies, people who stopped taking the drug tended to regain some or most of the weight over time. More on that later, as well as how to prevent the dreaded rebound effect.
Side Effects and Risks to Consider
Like any medication, GLP-1 agonists come with potential side effects. Most are gastrointestinal in nature and typically decrease over time:
Common Side Effects:
Nausea
Vomiting
Diarrhea
Constipation
Fatigue or dizziness
More Serious (But Rare) Risks:
Pancreatitis
Gallbladder issues (e.g., gallstones)
Kidney problems in people with dehydration
Possible thyroid tumors (seen in rodent studies; unclear in humans)
Certain people should not take GLP-1 drugs, such as those with:
Personal or family history of medullary thyroid carcinoma
Multiple endocrine neoplasia syndrome type 2 (MEN2)
A history of pancreatitis
It is not uncommon for individuals to experience more side effects right away while their bodies adjust to the medication. Typically, side effects reduce as time goes on. Starting low and increasing the dose slowly is the best practice for limiting, if not eliminating, side effects.
Always speak to a licensed provider to evaluate your health history and rule out these risks.
What Results Can You Expect?
Patients typically begin noticing appetite reduction within the first few weeks. Weight loss starts gradually and often builds over time.
Typical Outcomes:
First 4–6 weeks: Modest weight loss, usually 2–5 pounds
3–6 months: Average of 10–15% of starting weight lost
12 months and beyond: Some patients achieve 20%+ loss, especially with tirzepatide
However, results depend on many factors, including:
Diet quality
Physical activity
Stress and sleep
Medication adherence
Starting weight and metabolism
Jesse E had struggled losing weight his whole life. He was active, but had a sweet tooth that prevented him from consistently staying in a calorie deficit. Jesse lost more than 40 lbs (16.67% of his starting weight) in just 5 months at Central Park Weight Loss!
[INSERT BEFORE & AFTER PICS]
Like any other weight loss plan, it’s critical to incorporate healthy eating and physical activity to maximize outcomes. We’re huge proponents of resistance training (weight lifting) and high protein consumption to build/protect as much lean muscle mass as possible.
Is It Right for You? Key Considerations
GLP-1s may be a good option if:
Your BMI is 30 or higher, or 27+ with weight-related conditions (like high blood pressure or type 2 diabetes)
You’ve tried lifestyle changes with limited long-term success
You’re willing to take a weekly injection (some oral options are in development)
However, there are also important drawbacks to consider:
Cost: Without insurance, the name brand drugs can cost $1,000+ per month. Fortunately, there are compounding pharmacies who can make “generic” versions of these medications at a literal fraction of the cost
Supply issues: Some medications have had shortages due to high demand
Need for long-term use and/or a slow taper period: Many patients regain weight if they stop suddenly. Slowing weaning off the medication has shown to be effective for preventing weight rebound.
The Importance of Medical Supervision
Taking a GLP-1 agonist isn’t just about getting a prescription—it’s about entering into a supervised treatment plan.
Here’s why medical oversight matters:
Dosing is individualized and needs to be increased gradually
Providers can monitor for side effects and make adjustments as needed
Routine labs may be needed to check liver, kidney, or thyroid health
If side effects occur, a provider can adjust the dose or recommend alternatives
Avoid “clinics” that don’t offer full assessments or follow-ups. Misinformation on social media has led to people using compounded or counterfeit versions of GLP-1s, which can be dangerous. Work with a medical office who knows your medical history and will monitor your progress.
There are also plenty of options to purchase these products through “research manufacturers” who must advertise the products “are not for human consumption”. These products are not regulated and have a high likelihood for contamination. It’s important to go through a licensed medical provider who will write a personalized prescription through a FDA-regulated pharmacy.
Conclusion
GLP-1 agonists are changing the landscape of weight loss by offering meaningful results to people who have struggled for years. But like any medication, they come with risks and require long-term commitment.
Before you decide, speak with a licensed provider, weigh your options carefully, and consider whether this treatment aligns with your personal health goals.
Whether or not you choose a GLP-1 medication, what matters is finding a path to health that works for you and is sustainable long term. GLP-1s are a phenomenal “cheat code” for weight loss, but building long term healthy eating habits is crucial for lasting results.