The Science behind GLP‑1 Medications

GLP-1 receptor agonists like semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro) are transforming how we approach weight loss and metabolic health.

But how do these medications actually work inside the body and what should you know to get the best results?

In this article, we break down the science of GLP-1: what it is, how these drugs work, and why mimicking this hormone is helping millions achieve better health outcomes.

What Is GLP-1?

GLP-1 stands for glucagon-like peptide-1, a hormone produced in your gut that plays a key role in regulating blood sugar, appetite, and how fast food leaves your stomach. When you eat, GLP-1 is released and sends signals to your pancreas, brain, and stomach to help your body manage nutrients more effectively.

How GLP-1 Affects Blood Sugar

GLP-1 stimulates insulin production and reduces glucagon (a hormone that raises blood sugar), but only when glucose levels are elevated. This reduces the risk of hypoglycemia.

Key actions:

• Increases insulin secretion in response to food

• Suppresses glucagon secretion

• Improves insulin sensitivity over time

Result: More stable blood sugar levels, especially after meals.

How GLP-1 Suppresses Appetite

• GLP-1 receptors are located in the hypothalamus-the part of your brain that regulates hunger and fullness.

• When GLP-1 is active, it increases feelings of satiety (fullness), reduces cravings for high-calorie or sugary foods, and delays gastric emptying, so you stay full longer.

These effects explain why many users report reduced portion sizes and snacking.

Delayed Gastric Emptying 

GLP-1 slows down how quickly food moves from your stomach to your small intestine. This has two important effects:

• Extends the feeling of fullness after eating

• Blunts post-meal blood sugar spikes

For people with type 2 diabetes or insulin resistance, this can be a powerful stabilising effect.

How Semaglutide and Tirzepatide Mimic GLP-1

These medications are GLP-1 receptor agonists. That means they bind to and activate the same receptors as natural GLP-1, but in a longer-lasting way:

• Semaglutide mimics GLP-1 and stays active in the body for several days, allowing for once-weekly injections

• Tirzepatide activates both GLP-1 and GIP receptors, adding an additional appetite and insulin response benefit.

Both drugs have been shown to significantly reduce weight and improve metabolic markers when combined with diet and lifestyle changes.

GLP-1 Benefits Backed by Research

• Average weight loss with semaglutide: ~15% of body weight in clinical trials

• Improved HbA1c and fasting glucose levels

• Reduced risk of cardiovascular events in people with type 2 diabetes

• Lowered liver fat content in people with fatty liver disease

GLP-1 Limitations and Side Effects

While effective, GLP-1 medications can cause:

• Nausea

• Constipation

• Headaches

• Muscle or bone density loss if not supported nutritionally

That’s why pairing these medications with proper nutrition, resistance training, and strategic supplementation (like protein, electrolytes, and vitamin K2) is key for long-term success.

What Should You Do If You’re Starting GLP-1?

• Talk to your doctor about baseline labs (A1c, vitamin D, etc.)

• Track your progress: weight, muscle, energy, and side effects

• Build a support plan: nutrition, exercise, and supplements

Takeaway

GLP-1 medications work by mimicking a natural hormone that controls hunger, digestion, and blood sugar. The result is reduced appetite, better glycemic control, and significant weight loss-especially when combined with lifestyle changes.

Founder’s Note

As someone who works closely with GLP-1 users and the teams behind these medications, I see firsthand how science and real-life experience come together. At GLP-1 Approved, our mission is to translate the latest research into practical tips, curated products, and real-world support for your journey.

Disclaimer: This article shares general health and wellness strategies supported by research and the experience of GLP-1 users. However, your needs may differ. Always consult your personal healthcare provider before making changes to your health routine.