It isn't the dose on the pen that drives your results and your side effects — it's the level of medication actually in you. These drugs have a ~5–7 day half-life, so every injection stacks on what hasn't cleared yet. Set your personal level goal, model where you really are, and find the window where appetite control is good and side effects aren't.
Saved on this device only. Nothing is uploaded — there is no server and no account.
The amount of medication you're aiming to hold in your body — your personal number, chosen with your prescriber. Tap a preset to see the level each standard regimen settles at, or set anything in between. Everything below — dashboard, chart, planner — measures against this.
Presets show the steady-state peak (mg in-system) each standard dose reaches — context from the label, not a recommendation for you.
Estimated milligrams of medication still active in your body, modelled from your logged doses and your medication's half-life. The ring fills toward the level the highest standard regimen settles at; the green tick is your goal.
Toggle the layers you want. Dots are your symptom entries, plotted at the level you were at (green good · amber mild · red rough).
Projected level each day if you keep your current dose and interval. Green = near goal · amber = below (appetite may return) · red = above.
One tap for your routine dose — you can undo for a few seconds after.
For click-counted partial doses, back-dating, or notes. The model is only as good as the honesty of this log. Joining mid-therapy? Back-date your last 3–4 doses here — approximate dates are fine, and that alone makes your level ~95% accurate. Anything older has mostly cleared and isn't worth reconstructing.
Log this a few times a week — especially on good days and bad days. This is what turns the chart into your therapeutic window instead of a generic curve.
Saves: feeling good, appetite 7/10, energy 7/10, no side effects, right now.
0 = constantly hungry · 10 = no interest in food
0 = wiped out · 10 = great
Your goal (set at the top of the page) is the first lever — it sets your peak. The interval is the second — it sets your trough. Shortening the interval lifts your trough without raising your peak, the lever clinicians reach for when "hunger comes back late in the week". Standard dosing for the weekly medications is every 7 days; other intervals here are for exploring the model and for regimens your prescriber has actually set.
Calculated from your current modelled level, so it accounts for what's still in you. This is the "optional dose" idea — a late dose, an early dose, or a deliberate small correction — rather than blindly repeating last week's number.
Every Mounjaro KwikPen delivers its full dose in 60 clicks, so one click = pen strength ÷ 60. Pick the pen you actually have and this converts the dose above into clicks.
| Pen | 1 click | 2.5 mg | 5 mg | 7.5 mg | 10 mg | 12.5 mg | Full dial |
|---|
Full dial = 60 clicks on every strength. Verified against the click-count reference for all six KwikPen strengths.
Built purely from your own logs: at what modelled level did you feel good and eat well, and at what level did side effects start? The more you log, the sharper this gets.
Each entry you've logged, grouped by the level you were at.
| Level band | Entries | Appetite | Energy | Side effects | Read |
|---|
Everything lives in this browser's local storage. Clearing site data wipes it — export a backup, especially before changing device or browser.
GLP-1 medicines clear slowly — tirzepatide's half-life is about 5 days, semaglutide's about 7. A week after a 1 mg dose, roughly half of it is still in you. The next dose lands on top of that remainder, so your level keeps climbing for about 4–5 doses even if the number on the pen never changes.
That single fact explains a lot of lived experience: the same dose feeling stronger after a month, side effects arriving weeks into a "stable" dose, hunger returning late in the week, and one late dose throwing everything off.
Standard one-compartment model with first-order elimination. Your level is the sum of every dose decaying independently:
level(t) = Σ dosei × e−λ(t−ti), λ = ln2 ÷ half-life
Steady-state peak for a repeating dose D every τ days is D ÷ (1 − e−λτ). Everything is displayed as estimated mg still in your system. The "standard doses" chart lines and goal presets are the steady-state values each licensed dose settles at — e.g. 15 mg weekly tirzepatide settles at ≈24 mg in-system at peak, 5 mg weekly at ≈8 mg. (For the orally-dosed option, the displayed mg is swallowed-dose equivalent before absorption — treat it as a relative index, since only a small fraction is absorbed.)
Sanity check: a standard 2.5 mg → 5 mg tirzepatide step doubles your steady-state level (≈4 mg → ≈8 mg in-system) — which is why a single "small" ladder step can feel like a cliff, and why some clinicians work with intermediate exposure levels. If that interests you, it's a conversation to have with your prescriber.
Recent doses are almost all that matters. Each dose is ~97% cleared after five half-lives, so anything older than about 3½ weeks (tirzepatide) or 5 weeks (semaglutide) has essentially left your system — there is no value in reconstructing months of old records.
How much of your true level you capture by logging only your most recent doses (weekly dosing):
No records at all? Just start with your next dose. Early readings will understate your true level (never overstate it), and the gap closes by itself as old unlogged doses clear — the model is fully tuned after ~3–4 weeks of normal logging. While that's happening, a "tuning" tag on the dashboard shows the exact date full accuracy arrives. If your first logged dose really was your first-ever dose, your level is already exact and you can ignore the tag.
How precise do the dates need to be? Day-level is fine. A 12-hour error moves a single dose's contribution by ~7% and your total level by much less — the exact hour barely matters.
When does each benefit start? Your current level, next trough and dose-due countdown: from the first logged dose. Peak-to-trough swing: after 2. Near-full accuracy: last 3–4 doses logged. Your personal therapeutic window: at least 4 "How I feel" check-ins, ideally spread across different levels.
It is genuinely useful for seeing relative change and spotting patterns. It is not a substitute for clinical judgement.
The "manage the level, not the dose" framing and the peak/trough-as-two-levers idea come from a clinical whitepaper on pharmacokinetic GLP-1 dosing by Dr Ian J. Ellis (the MyLevel framework; that paper uses a normalised 0–50 scale — this app shows estimated mg instead). The underlying pharmacology — long half-life, accumulation to steady state, exposure-driven response — is well established and uncontroversial. The specific clinical outcome claims in that paper are single-practice observational data and should be treated as promising but unproven.
The KwikPen click figures come from a click-count reference covering all six Mounjaro pen strengths; all of them reduce to the same rule of 60 clicks per full dial, which is what this app implements.