Why These Injections Are Used for Weight Loss
Tirzepatide and semaglutide belong to a class of medicines that act on appetite-regulating pathways in the body. Tirzepatide activates both GIP and GLP-1 receptors; semaglutide activates GLP-1 receptors. Both are commonly reported to reduce appetite, increase feelings of fullness, and slow stomach emptying — effects that many people find support changes to how much and how often they feel like eating.
These medicines are prescription-only and are supplied as pre-filled injectable pens, typically administered once a week. The specific injection used for weight loss in your case — whether the Mounjaro injection for weight loss, a semaglutide injection for weight loss, or another formulation — will have been chosen and prescribed by your own clinician based on your individual circumstances. Suitability and dosing are always decided by a prescriber, not self-selected.
Common Injection Sites
Most people inject into one of three areas: the abdomen, the front of the thigh, or the upper arm. Rotating between sites with each weekly injection is generally recommended to reduce the chance of skin irritation or changes at the injection site. Your prescriber or the patient information leaflet that came with your pen will give you guidance specific to your medicine.
For a closer look at how different injectable options compare, see our overview of weight-loss injections or read more about what diabetes injection is used for weight loss and the specific options available.
If you want practical detail on the injections themselves, our guide to injections for weight loss covers the basics in plain language.
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.
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How GLP Trackr Helps You Stay on Top of Your Injections
Remembering which site you injected last week — and whether it was the left or right side — is one of those small details that is easy to lose track of across a months-long weekly schedule. GLP Trackr's injection-site tracking lets you log the exact site after each injection, and the app uses that history to suggest where to inject next, so rotation becomes automatic rather than something you have to remember.
Alongside site tracking, the app logs each dose and the date and time it was given, building a clear record you can refer back to at any point. Dose reminders mean your weekly schedule stays on track even when life gets busy.
You can also use the app to log any side effects you notice around injection day — nausea, injection-site reactions, fatigue — and review patterns over time. That kind of record can be genuinely useful to bring to your next prescriber appointment. For more on the Mounjaro injection for weight loss specifically and how people use it, see our Mounjaro injection for weight loss page.
GLP Trackr is a tracking companion, not a medical service — it helps you stay organised and informed, but any questions about your injection technique, site reactions, or dose should go to your prescriber or doctor. If you notice a reaction at an injection site that is severe, spreading, or not settling, contact your healthcare professional promptly.
Ready to take the guesswork out of site rotation? Download GLP Trackr on the App Store or Google Play and start a free 7-day trial — log your first injection today and let the app handle the rotation history from there.
What does glptrackr include?
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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.
Tirzepatide (Mounjaro) and semaglutide (Wegovy) are prescription-only injectable medicines originally linked to diabetes research that are now prescribed specifically for weight management. Both are given once weekly and must be prescribed by a qualified clinician.
Common injection sites are the abdomen, front of the thigh, and upper arm. Rotating between sites each week is generally recommended. Your prescriber or the patient information leaflet supplied with your pen will provide guidance specific to your medicine.
Rotating injection sites is generally advised to reduce the risk of skin irritation or changes at the site. Most people move between different areas — such as the abdomen and thigh — and alternate sides with each injection. Check your patient information leaflet for specific advice.
GLP Trackr lets you log each injection's site, dose, date, and time. It tracks your rotation history and suggests where to inject next. The app also sends dose reminders so your weekly schedule stays consistent. It is a tracking tool, not a medical service.
No. Tirzepatide and semaglutide are not insulin. They work on GLP-1 and GIP appetite-regulating pathways rather than directly controlling blood sugar in the way insulin does. Your prescriber can explain how your specific medicine works in your situation.