How GLP-1 weight loss drugs work: everything you need to know

Ed Milner | Last update: 30th June 2025

First Things First: What Is a GLP-1?

GLP-1 stands for glucagon-like peptide-1, a natural hormone your body produces. It plays a big role in regulating appetite, digestion and blood sugar.

GLP-1 medications (also called GLP-1 receptor agonists) like semaglutide (Wegovy, Ozempic) and tirzepatide (Mounjaro) mimic this hormone to help with weight loss and blood sugar control.

These drugs are not magic — but they are powerful tools. They create the ideal conditions for fat loss, appetite control and better energy balance.

How Do They Actually Work?

Here’s what happens in your body when you take a GLP-1:

1. Appetite Regulation

• GLP-1 meds act on your brain, especially the hypothalamus, which controls hunger.
• They reduce cravings — especially for high-calorie, high-carb comfort foods.
• You feel full quicker and satisfied with less.

2. Delayed Gastric Emptying

• These drugs slow how quickly food leaves your stomach.
• That means you stay fuller for longer and feel less tempted to snack.

3. Reduced Calorie Intake

• Because you’re eating smaller portions and snacking less, you naturally take in fewer calories without obsessing or tracking.

4. Blood Sugar Regulation

• GLP-1s help your body use insulin more effectively.
• This keeps blood sugar stable, reducing crashes and sugar cravings.

5. Behavioural Shifts

• Many users say they feel more mindful with food.
• Emotional eating, binge eating and food noise (constant thoughts of food) reduce.

“The food noise is just… gone. I can actually think without obsessing about what I want to eat next.”

6. Taste Preferences May Change

• Some people notice they don’t crave sugar or fatty foods as much.
• You may find yourself naturally reaching for healthier options.

7. Possible Boost to Energy Use

• There’s some evidence these drugs may slightly increase how much energy you burn, but appetite suppression is the main factor.

Why They Work Best With Lifestyle Change

Ultimately, weight loss comes down to a healthy calorie deficit and a functioning metabolism.

GLP-1s help you get there easier — but:

• If you don’t eat enough protein, you’ll lose muscle instead of just fat.
• If you’re sedentary, your metabolism can slow.
• If you eat highly processed food, you’ll feel worse, even with the meds.

“When I paired my injection with protein, strength training and hydration, the changes felt so much deeper. I had more energy, fewer side effects, and felt proud of the habits I was building.”

The goal is not just weight loss — it’s sustainable, healthy living.

Pros of GLP-1 Medications

✅ Support significant weight loss without surgery or extreme diets
✅ Reduce cravings and emotional eating
✅ Improve blood sugar control
✅ May lower cardiovascular risk (e.g. Wegovy and Mounjaro have added heart benefits) 

✅ Help reset your relationship with food
✅ Can create a “quiet” brain that lets you focus on life, not eating

Common Side Effects to Watch Out For

Not everyone gets side effects, but it’s good to be aware:

• Nausea and vomiting (especially early on)
• Constipation or diarrhoea
• Bloating and gas
• Headaches or dizziness
• Mild increase in heart rate
• Fatigue or low energy

More serious but rare side effects can include:

• Severe abdominal pain
• Pancreatitis
• Gallbladder issues
• Jaundice
• Kidney complications

Always consult your doctor or healthcare provider before starting or adjusting any GLP-1 treatment.

GLP-1s in the Bigger Picture: A Look Ahead

Research is still evolving. But what we know so far:

• GLP-1s can help prevent diabetes in high-risk groups
• New drugs (like dual/triple agonists) may offer even better results with fewer side effects
• Long-term use can maintain weight loss if paired with behaviour change
• Studies suggest GLP-1s may even reduce food-related brain activity (that constant “food noise”)

“It’s not just the scale moving — it’s the way my brain feels. I’m no longer trapped in constant food thoughts. I feel free.”

Quick Recap

GLP-1 meds like Wegovy, Ozempic and Mounjaro work by:

• Controlling appetite in the brain
• Slowing digestion
• Helping you feel full longer
• Reducing emotional and binge eating
• Supporting blood sugar balance

But they work best when paired with:

• Protein-rich, nutrient-dense food
• Movement (especially strength training)
• Good sleep, hydration and stress management

They’re tools — powerful ones — but they’re not magic on their own.

Want to Know What It Looks Like in Real Life?

Join the SlimrChat community. Our members share what actually works — the food, the habits, the hard days and the wins. You’ll find real talk, honest support and tips to help you make the most of your meds. No shame. No fluff. Just real people getting real results. Click the button below and join the chat!