- Tracking your GLP-1 injections ensures you never miss a dose, helps you rotate injection sites correctly, and creates a treatment timeline you can share with your doctor.
- Every injection should be logged with the date, time, dose (mg), injection site, and any immediate reactions.
- Rotating injection sites in a consistent pattern prevents lipodystrophy — hardened or lumpy tissue that can impair drug absorption.
- Semaglutide has a half-life of approximately 7 days, with drug levels reaching steady state after 4-5 weeks at each dose. A drug-level visualization helps you understand why side effects peak on certain days.
- A dedicated tracking app like MyWhy makes injection logging, site rotation, dose escalation tracking, and side effect logging effortless — and it's completely free.
Tracking your GLP-1 injections ensures you never miss a dose, helps you rotate injection sites, and creates a treatment timeline you can share with your doctor. A dedicated tracking app makes this effortless. Whether you're on Ozempic, Wegovy, or Mounjaro, the weekly dosing schedule means it's deceptively easy to lose track of when you last injected, where you injected, and what dose you're on. This guide covers exactly what to log, why each detail matters, and how to turn injection tracking into a five-second habit.
Why Tracking Your Injections Matters
GLP-1 receptor agonists like semaglutide and tirzepatide are dosed once weekly. That sounds simple — until you're four months into treatment and trying to remember whether you injected on Tuesday or Wednesday last week, or whether you used your left thigh or right abdomen. Here's why consistent tracking is worth the effort:
- Weekly dosing is easy to forget. Unlike a daily medication that becomes part of your morning routine, a once-weekly injection doesn't have the same built-in habit loop. One missed week turns into two without a clear record to catch the gap.
- Missed doses can increase side effects. When you skip a dose and then resume, your body has to readjust. This can cause a resurgence of nausea, GI discomfort, and other side effects that had already subsided — essentially restarting the adjustment period for that dose level.
- Your doctor needs injection history. When your provider asks how you've been tolerating your medication, "fine, I think" isn't very helpful. A complete injection log with dates, doses, sites, and side effects gives them the data they need to make informed decisions about your treatment — especially during dose escalation.
What to Log for Each Injection
Every time you inject, capture these five pieces of information. It takes less than 30 seconds and creates a medical record that's genuinely useful:
| Data Point | Example | Why It Matters |
|---|---|---|
| Date & time | March 9, 2026 at 8:00 AM | Confirms you're staying on schedule and helps identify patterns in side effects by time of day. |
| Dose (mg) | 0.5mg | Essential during dose escalation. Lets you correlate side effects and weight changes to specific dose levels. |
| Injection site | Left abdomen | Ensures you're rotating sites properly. Prevents injecting the same spot repeatedly. |
| Injection site condition | No redness or swelling | Catches early signs of injection site reactions before they become a problem. |
| Immediate reactions | Mild stinging for 10 seconds | Some reactions indicate technique issues (injecting too fast, wrong angle) that can be corrected. |
A GLP-1 companion app lets you log all five data points with a few taps immediately after injection. The key is capturing this information in the moment, not trying to reconstruct it days later from memory.
Injection Site Rotation: Why It Matters
Injection site rotation is one of the most overlooked aspects of GLP-1 treatment. Injecting into the same spot repeatedly can cause lipodystrophy — hardened, lumpy, or dimpled areas of tissue under the skin. Beyond the cosmetic concern, lipodystrophy impairs drug absorption, meaning the medication may not work as effectively even though you're taking the correct dose.
The FDA-approved injection sites for semaglutide and tirzepatide are the abdomen (at least 2 inches from the navel), the front of the thighs, and the upper arms (back area, typically administered by someone else). A simple rotation pattern ensures you cycle through all available sites:
- Week 1: Right abdomen
- Week 2: Left abdomen
- Week 3: Right thigh
- Week 4: Left thigh
- Week 5: Upper arm (right or left, alternating)
- Week 6: Restart the cycle
Within each region, shift the exact injection point by at least one inch from the previous injection in that area. Your tracking app should record which site you used each week so the rotation stays consistent even when you can't remember where you injected last month.
Understanding Drug Levels
Semaglutide has a half-life of approximately 7 days, which is why it's dosed weekly. But the practical implications of this pharmacokinetic profile go deeper than dosing frequency:
- Drug levels build gradually. After your first injection, you don't have a full week's worth of medication in your system. It takes 4-5 weeks of consistent weekly dosing at the same level for semaglutide to reach steady state — the point where the amount entering your body equals the amount being eliminated.
- Side effects often peak mid-week. Drug concentration is highest 1-3 days after injection. This is why many patients experience the worst nausea on days 2-3, with improvement by days 5-7. Knowing this pattern helps you plan meals, activities, and injection timing.
- Drug-level visualization shows you the curve. Rather than guessing where you are in the weekly cycle, a drug-level chart plots estimated medication levels over time. This makes the abstract concept of half-life concrete — you can see exactly why you feel different on day 2 versus day 6.
Dose Escalation Tracking
Most GLP-1 medications follow a gradual dose escalation schedule — starting low and increasing monthly. Wegovy escalates from 0.25mg to 2.4mg over 16-20 weeks. Mounjaro moves from 2.5mg to up to 15mg. This escalation is the phase where tracking matters most.
At each new dose level, note:
- Date of the dose increase. Creates a clear timeline that you and your doctor can reference when reviewing tolerability.
- Side effects in the first 1-2 weeks. The initial days at a new dose are when GI side effects typically flare. Recording their severity and duration helps predict how you'll respond to the next increase.
- Appetite and hunger changes. Many patients notice a distinct shift in appetite suppression at certain dose levels. Documenting this helps your provider determine if you're at a therapeutic dose or need to continue escalating.
- Weight trend at each level. Weight loss often accelerates at higher doses. Tracking the rate of loss at each dose helps your doctor decide whether to continue escalating or hold at a dose that's producing good results with tolerable side effects.
Not everyone reaches the maximum dose, and that's expected. Some patients achieve meaningful results at lower doses. Your dose escalation log gives your doctor the evidence to make that decision confidently rather than following the standard schedule by default.
What to Do If You Miss a Dose
Missed doses happen. What matters is how you respond. For semaglutide (Ozempic and Wegovy), the general guidance is:
- If fewer than 5 days have passed since your scheduled injection, take the missed dose as soon as possible. Then resume your regular weekly schedule.
- If 5 or more days have passed, skip the missed dose entirely and take your next dose on the regularly scheduled day.
- Never double up. Do not take two doses at once to make up for a missed injection.
Log the missed dose in your tracking app with a note about why it was missed and what you did. This creates an accurate timeline — gaps and all — that your doctor can review at your next appointment.
How MyWhy Tracks It All
MyWhy was built specifically for GLP-1 patients who want comprehensive injection tracking without complexity. Here's what it handles:
- Injection logging. Log each injection with dose, site, date, and time in a few taps. The app maintains your complete injection history and makes site rotation easy to follow.
- Drug-level visualization. See estimated medication levels over time based on your actual injection log. Understand why you feel different on day 2 versus day 6 and what happens when you miss a dose.
- Treatment timeline. A chronological view of your entire treatment — every dose escalation, every injection, every note — that you can share with your doctor at appointments.
- Side effect logging. Record side effects as they happen with severity ratings and notes. Correlate symptoms to specific dose levels, days post-injection, and injection sites.
- Weight trends and meal check-ins. Track the bigger picture alongside your injections. See how your weight responds to each dose level and build awareness of your evolving relationship with food.
All of these features are completely free. No subscription walls, no premium tiers for core tracking features. For a full walkthrough, read our GLP-1 companion app guide, or see how MyWhy compares in our best free GLP-1 tracking apps comparison.