⚠️ Medical disclaimer: This page is for informational purposes only and does not constitute medical advice. Consult a licensed healthcare provider before starting any medication.
GLP-1 medications are a class of drugs that have transformed how doctors treat type 2 diabetes and obesity. In recent years, names like Ozempic, Wegovy, Mounjaro, and Zepbound have become household terms — but what exactly are they, and how do they work?
GLP-1: The Natural Hormone
GLP-1 stands for glucagon-like peptide-1. It is a hormone your body produces naturally in the gut after you eat. When food enters your digestive system, GLP-1 is released and does several things:
- Signals your pancreas to release insulin (lowering blood sugar)
- Suppresses glucagon, which prevents the liver from releasing excess glucose
- Slows down how quickly food leaves your stomach (gastric emptying)
- Sends fullness signals to the brain, reducing appetite
The problem for many people with type 2 diabetes or obesity is that this natural GLP-1 response is blunted or insufficient. GLP-1 receptor agonist medications mimic this hormone — and do so far more powerfully and for much longer than the body’s natural version.
What GLP-1 Medications Do
By activating GLP-1 receptors in the body, these medications:
- Lower blood sugar levels without causing dangerous hypoglycaemia
- Dramatically reduce appetite — most users eat significantly less without trying
- Slow gastric emptying — food sits in your stomach longer, keeping you fuller
- Produce significant, sustained weight loss — often 10–22% of total body weight
- Reduce cardiovascular risk in people with diabetes or obesity
The Main GLP-1 Medications
Ozempic | Semaglutide | Type 2 diabetes (off-label weight loss) | Once weekly injection
Wegovy | Semaglutide | Weight management | Once weekly injection
Rybelsus | Semaglutide | Type 2 diabetes | Daily oral tablet
Mounjaro | Tirzepatide | Type 2 diabetes (off-label weight loss) | Once weekly injection
Zepbound | Tirzepatide | Weight management | Once weekly injection
Saxenda | Liraglutide | Weight management | Daily injection
Foundayo | Orforglipron | Weight management (new 2026) | Daily oral pill
Semaglutide vs Tirzepatide: What is the Difference?
Semaglutide (Ozempic, Wegovy) activates one receptor — the GLP-1 receptor. Tirzepatide (Mounjaro, Zepbound) activates two — the GLP-1 receptor AND the GIP receptor. This dual action is why tirzepatide generally produces greater weight loss than semaglutide.
In head-to-head trials, Zepbound produced around 20% average weight loss compared to 14% for Wegovy over 72 weeks.
What Are Compounded GLP-1 Medications?
Compounded semaglutide and tirzepatide are versions of these medications prepared by licensed compounding pharmacies rather than manufactured by the original drug companies. They became widely available when brand-name versions faced supply shortages.
Compounded versions can cost as little as $99–$150 per month compared to $900–$1,400 for brand names.
→ See our Best GLP-1 Clinics page to compare telehealth providers offering compounded options.
Who Should Consider a GLP-1 Medication?
GLP-1 medications are typically prescribed for:
- Adults with type 2 diabetes who need better blood sugar control
- Adults with a BMI of 30 or higher (obesity)
- Adults with a BMI of 27 or higher with at least one weight-related condition (hypertension, sleep apnea, high cholesterol)
They are not appropriate for everyone. People with a personal or family history of medullary thyroid cancer or multiple endocrine neoplasia type 2 should not use GLP-1 medications. Always discuss with a doctor before starting.
How Much Weight Can You Lose?
- Semaglutide (Wegovy): average 15–17% body weight loss over 68 weeks
- Tirzepatide (Zepbound): average 20–22% body weight loss over 72 weeks
- Liraglutide (Saxenda): average 5–8% body weight loss
Results vary based on starting weight, diet, exercise, and how long you stay on the medication. Most people begin to see results within 4–8 weeks.