GLP-1 Medications: What They Are, How They Work, and What to Know Before Starting
What are GLP-1 receptor agonists?
GLP-1 receptor agonists are a class of medications used to treat:
Type 2 diabetes
Overweight and obesity
They work by mimicking a natural hormone in your body called GLP-1 (glucagon-like peptide-1).
This hormone is released from your intestines after you eat and helps regulate:
Blood sugar
Appetite
Digestion
Common GLP-1 medications
Several GLP-1 medications are currently FDA-approved:
For type 2 diabetes:
Ozempic (semaglutide) – injection
Rybelsus (semaglutide) – oral tablet
For weight loss:
Wegovy (semaglutide) – injection (now available in oral form)
While these medications are often grouped together, they may have slightly different effects and dosing schedules.
There are newer forms of GLP-1s, but for simplicity I only named a few since they share similar characteristics.
How do these medications work?
GLP-1 medications act on multiple systems in the body:
Increase insulin release (only when blood sugar is high)
Decrease glucagon (a hormone that raises blood sugar)
Slow down stomach emptying
Reduce appetite through effects on the brain
Together, these effects lead to:
Better blood sugar control
Weight loss
Improvement in overall metabolic health
Benefits of GLP-1 medications
1. Blood sugar control
In people with diabetes:
Hemoglobin A1C can drop by a little over 1%
This may sound small, but in diabetes care, that is a meaningful improvement.
2. Weight loss
In studies:
Injectable semaglutide led to about 14.9% average body weight loss
This level of weight loss can:
Reduce strain on joints
Improve mobility
Lower risk of chronic disease
3. Heart and kidney protection
GLP-1 medications have also been shown to:
Reduce cardiovascular disease risk
Slow decline in kidney function
Lower risk of end-stage kidney disease
4. Liver health
Semaglutide (Wegovy) has shown benefits in:
Non-cirrhotic MASH (fatty liver disease with inflammation)
Particularly in patients with moderate to advanced fibrosis
Common side effects
The most common side effects involve the gastrointestinal system.
About 74% of patients experience:
Nausea
Diarrhea
Vomiting
Constipation
These often improve over time but can be limiting for some patients.
Other risks to be aware of
Gallbladder disease (about 37% increased risk)
Pancreatitis (rare, but can happen especially with rapid dose increases)
Increased heart rate (seen in ~41% of patients)
Gastroparesis (severe delayed stomach emptying in some cases)
Who should NOT take these medications
GLP-1 medications are contraindicated in patients with:
Personal or family history of medullary thyroid cancer
Multiple endocrine neoplasia type 2 (MEN2)
Important safety considerations
Should be stopped at least 2 months before pregnancy
Usually discontinued 2–3 weeks before surgery due to delayed gastric emptying
What happens if you stop the medication?
Weight regain is common.
In studies:
Patients regained about 11% of lost weight over one year
This highlights an important point:
These medications often require long-term use to maintain results
How I think about GLP-1 medications in practice
These medications can be very effective.
For some patients, they:
Help reduce weight enough to relieve joint pain
Make it easier to start exercising again
Provide the initial momentum needed for long-term change
But they are not a replacement for lifestyle
If someone is capable of making lifestyle changes, that should always be the foundation.
Why:
Healthy habits are sustainable
They improve multiple aspects of health
They don’t rely on long-term medication use
Bottom line
GLP-1 medications are powerful tools that can:
Improve blood sugar
Promote significant weight loss
Reduce cardiovascular and kidney risk
But they also come with:
Side effects
Long-term considerations
The need for careful patient selection
The goal is not just weight loss or better numbers—it’s long-term health.
And for most people, that still starts with:
Nutrition
Movement
Sleep
Consistency
Medications can help—but they work best when combined with the basics.