What GLP-1 Is and How It Works in the Body
Glucagon-like peptide-1 is released by specialised cells in the small intestine in response to food. In medical terms, it is an incretin hormone — a signalling molecule that helps coordinate the body's response to a meal.
What GLP-1 does, step by step
- Signals fullness: GLP-1 acts on receptors in the brain — particularly in the hypothalamus — to increase the sense of satiety and reduce appetite. Many people describe this as a quietening of "food noise," the constant background drive to eat.
- Slows gastric emptying: It slows the rate at which food leaves the stomach, which helps you feel fuller for longer after a meal. This effect is commonly reported to ease somewhat over time as the body adjusts.
- Supports blood sugar balance: GLP-1 encourages the pancreas to release insulin in response to rising blood glucose, and simultaneously reduces the release of glucagon (a hormone that raises blood sugar). This happens in a glucose-dependent way, meaning the effect is tied to what you have eaten.
What GLP-1 stands for — in plain language
The name breaks down as: glucagon-like (structurally similar to the hormone glucagon), peptide (a short chain of amino acids), 1 (the first identified member of this peptide family). In everyday use, people often refer to GLP-1 receptor agonist medicines — such as Wegovy (semaglutide) — simply as "GLP-1s." Mounjaro (tirzepatide) works on the GLP-1 receptor and a second receptor called GIP, making it a dual agonist.
For a closer look at how one of these medicines interacts with the body specifically, see our page on what Mounjaro does to your body, or explore how the GLP-1 pathway produces its effects in more detail.
According to NHS guidance, GLP-1 receptor agonists are a recognised class of medicines used in the management of weight and type 2 diabetes — always under prescriber supervision.
average weekly weight change in the first 16 weeks of Mounjaro & Wegovy use*
Tracking the right four numbers — weight, waist, protein and dose — turns a noisy chart into a clear story. That's the loop GLP-1 users keep coming back for.
AI Meal Tracking. Built for GLP 1 Appetites.
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Tracking Your GLP-1 Journey With GLP Trackr
Understanding the biology of GLP-1 is one thing — living with it day to day is another. One of the most useful things you can do while on a GLP-1 medicine is track how your body is responding over time, so you have something concrete to bring to appointments with your prescriber.
GLP Trackr's side-effect and symptom logging lets you record how you feel after each dose — nausea, changes in appetite, energy levels, digestion — and surfaces patterns across days and weeks. Because GLP-1 medicines affect appetite and gastric emptying, noticing when certain sensations peak and ease can help you and your prescriber understand how your body is adjusting.
The app's daily check-in captures food noise levels alongside mood, energy, sleep, and weight in about 30 seconds each morning, building a picture of how the GLP-1 effect is shifting as your treatment progresses. That data feeds into the insights view, so trends become visible rather than guesswork.
If you want to understand more about whether this class of medicine is effective in practice, our page on whether GLP-1 medicines really work covers what the research generally shows — and our hub on how Mounjaro works goes deeper on the dual GIP and GLP-1 mechanism.
GLP Trackr is an informational and tracking tool — it is not a substitute for your prescriber's advice. If you experience symptoms that are severe, persistent, or concern you, contact your healthcare professional promptly.
Ready to start tracking how your body responds to your GLP-1 medicine? GLP Trackr is available free on the App Store and Google Play, with a 7-day trial to explore everything — download it and see your journey start to take shape.
What does glptrackr include?
10+ powerful features. One app. Built specifically for Mounjaro and Wegovy users.
Everything your GLP-1 journey needs. Free to try for 7 days.
Morning Check-In
Start every day with a 60-second wellness check-in. Log how you're feeling, track nausea, appetite, energy, and mood — giving you and your care team a complete picture of how your medication is working.
Injection Tracking
Log every dose with a single tap. Track your dose history, phase in your cycle, estimated medication levels, and upcoming injection dates — with reminders so you never miss a scheduled shot.
Hydration Reminders
Staying hydrated is especially important on GLP-1 medications. Set daily water targets, log intake throughout the day, and receive smart nudges when you're falling behind your goal.
Smart Meal Planning
Personalized meal plans built around your current dose phase and side effects. Every meal is GLP-1 optimized — high in protein, gentle on the stomach, and scaled to your reduced appetite.
Recipe Library
Browse 50+ high-protein, GLP-1-friendly recipes filtered by meal type, prep time, and dietary needs. Every recipe includes full nutrition info, step-by-step instructions, and tips for eating with side effects.
Progress Analytics
Beautiful, easy-to-read charts show your weight loss trajectory, weekly nutrition trends, medication responses, and wellbeing scores over time — turning raw data into genuine insights.
AI Meal Scanning
Snap a photo of any meal and get a full nutrition breakdown in seconds — calories, protein, carbs, fat, and fibre. No searching. No manual logging. Just point, snap, and track.
Exercise & Steps
Log walks, workouts, and movement with activity targets that flex with your energy levels. On lower-energy dose days, gentler targets keep you moving without burning out.
Community Support
Connect with thousands of others navigating the same medication journey. Share milestones, ask questions, find accountability partners, and get support from people who truly understand.
Never Forget a Dose Again.
Log your Mounjaro or Wegovy injection in seconds. Track your pen, your dose level, and your injection site — so you always know exactly where you are in your treatment.
Watch Your Body Transform, Week by Week.
Log your weight, measurements, and how you're feeling after each dose. GLPTrackr turns your data into clear, motivating charts that show you how far you've really come.
You're Not on This Journey Alone.
Connect with thousands of real GLP-1 users sharing their wins, side effect tips, and meal ideas. Get the support of people who truly get it — because they're living it too.
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The Most Advanced GLP-1 Brain Ever Built.
The first AI built exclusively for GLP-1 weight loss. Every insight, every meal plan, every prediction trained on one thing only: helping you get the most out of your medication.
Knows Your Cycle
GLPIQ tracks where you are in your injection cycle and adjusts everything around it: lighter meals on nausea days, higher protein when appetite returns, and smarter targets as your medication level shifts.
Predicts Before You Feel It
GLPIQ learns your personal side effect patterns over time. After a few cycles, it starts warning you the morning before a rough day — and adjusts your meal plan automatically.
Finds Your Golden Dose
GLPIQ analyses every dose you've been on: weight loss rate, side effects, food noise, mood, protein adherence and tells you which dose gave you the best results. No other app does this.
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Frequently asked questions.
GLP-1 stands for glucagon-like peptide-1. It is a hormone produced in the gut after eating that helps regulate appetite, gastric emptying, and blood sugar. The name reflects its structural similarity to glucagon and its classification as a peptide hormone.
GLP-1 signals the brain to reduce appetite, slows how quickly food leaves the stomach, and encourages insulin release after meals. Together, these effects help regulate food intake and blood sugar levels. GLP-1 receptor agonist medicines work by mimicking or amplifying these natural signals.
In medical terms, GLP-1 (glucagon-like peptide-1) is an incretin hormone — a gut-derived signalling molecule released in response to food. It acts on receptors in the brain, pancreas, and digestive tract. Medicines described as GLP-1 receptor agonists are designed to activate these receptors.
Mounjaro (tirzepatide) acts on the GLP-1 receptor and also on a second receptor called GIP (glucose-dependent insulinotropic polypeptide), making it a dual agonist. Wegovy (semaglutide) acts on the GLP-1 receptor. Both are prescription-only medicines; your prescriber determines which is appropriate for you.
Logging symptoms, appetite, energy, and weight over time lets you spot patterns and have more informed conversations with your prescriber. GLP Trackr's side-effect tracker and daily check-in are designed to capture exactly these responses throughout your treatment journey.