The Tiro blog
GLP-1 FAQ: the questions that start after shot one.
Protein, dosing, side effects, plateaus, and keeping your muscle — grounded in the trials and the labels, written for real people on the medication.
This is a GLP-1 FAQ for people who have already started. Most GLP-1 question pages answer what the drug is and whether you qualify; the answers below are the ones that come up in month three — a missed Thursday shot, a vial at a new strength, food noise back on day six, a plateau at month five, and what happens when you stop.
Just prescribed
GLP-1 questions, answered
Twenty questions people ask once they are already injecting. Each answer resolves the question; the linked guide carries the reasoning, the caveats and the sources.
Missed doses & timing
I missed my Zepbound shot — is it too late?
Not if you are inside four days. The label says take it as soon as possible within 4 days (96 hours) of the missed dose; after that, skip it and resume your regular weekly day. Never take two doses to catch up. (Zepbound US prescribing information)
The 4-day rule for a missed Zepbound dose →Check the missed-dose window for your brand →
Ozempic missed dose — how many days do I have?
Five. The Ozempic label says to take a missed dose as soon as possible within 5 days after the missed dose; after 5 days, skip it and resume your regular weekly schedule. The windows differ by brand, so do not assume yours matches. (Ozempic US prescribing information)
Should I inject in the morning or at night?
Either — weekly GLP-1s are not tied to a time of day. The choice that matters is the day. For a lot of people the roughest stretch falls a couple of days after the shot, so pick a day that puts it where your week has slack.
When can I move up a dose?
Your prescriber decides, but the ladders are spaced for a reason: tirzepatide reaches steady-state plasma concentrations after 4 weeks of once-weekly dosing, with a half-life of about 5 to 6 days, which is why the label spaces escalation steps four weeks apart. (Zepbound US prescribing information)
Map your titration dates onto a calendar →The Zepbound titration ladder, step by step →
Vials, pens & units
How many mL is in a Zepbound vial?
Half a millilitre. Zepbound is supplied as single-dose pens and single-dose vials at 2.5, 5, 7.5, 10, 12.5 and 15 mg, each per 0.5 mL — so the strength on the label is per half a millilitre, not per millilitre. (Zepbound US prescribing information)
How many mL and doses are in a Zepbound vial →Convert Zepbound vial units into milligrams →
My new vial is a different strength — do I draw the same amount?
No. Units are your dose divided by the concentration, so a stronger vial means fewer units for the same dose. Re-do the division every time the strength changes — skipping it is the most common way people accidentally double up.
Work out the new units after a vial strength change →Why a new vial strength can make you draw double →
How many clicks is my Mounjaro dose?
Not a number the manufacturer will give you. Every KwikPen strength delivers its dose in the same 0.6 mL, and community charts assume 60 clicks to a full dose — but that is arithmetic, not a licensed instruction, and Lilly says the KwikPen Instructions for Use provide no method for dialling less than the full fixed dose. Clicks only carry a milligram value on compounded tirzepatide in a click-dosing pen, where the figure depends on that pen’s concentration.
What a click is worth on each KwikPen strength →Why Lilly says not to count pen clicks →
How do I convert mg to units?
Divide your dose in milligrams by the vial’s concentration in mg per mL, then read that volume on a U-100 syringe, where 100 units is 1 mL. The trap is the label: it states an amount and a volume, not a concentration.
Convert a tirzepatide dose in mg into U-100 units →Convert a compounded semaglutide dose into units →
Protein & nutrition
How much protein do I need on a GLP-1?
More than you will feel like eating. The target is set from your body weight rather than a flat number, and the general adult baseline was never designed for someone losing weight quickly — it exists to prevent deficiency, not to protect muscle.
Calculate your daily protein floor →How much protein you actually need on a GLP-1 →
How many grams of protein per meal on Ozempic?
Your daily floor divided by the meals you can realistically finish — which on a bad week may be four small ones rather than three. When solids are hard, a protein drink counts. The daily total matters more than any single meal.
Why is my hair falling out on Mounjaro?
This is almost always a question about the speed of the weight loss rather than about the injection itself. The guide covers what the evidence does and does not support about shedding during rapid loss, and where protein intake is the part you can act on.
Side effects & the weekly curve
When are Zepbound side effects worst?
The pattern people describe most often is that injection day is uneventful and the following few days are not, easing again towards the end of the week. Large meals make it worse, and the fix is usually portion size rather than which foods.
What happens when I increase my Ozempic dose?
Two different things get confused. The rough patch after a step-up arrives within days; the genuinely new plateau is much later — semaglutide has a half-life of about 1 week and the label puts steady-state exposure at 4 to 5 weeks of weekly dosing. (Ozempic US prescribing information)
The day-by-day timeline when you increase your Ozempic dose →Plot your GLP-1 level between shots →
Why did my food noise come back?
Most often it is the end-of-week trough: appetite suppression is strongest in the days after your shot and fades as levels dip before the next one. Noise that is there all week, and is not rescued by the next injection, is a different pattern.
Is food noise on 5mg Mounjaro normal?
Common, and usually not a sign the medicine has stopped working. Returning noise can be a signal you are ready to step up, but only your prescriber decides that — so track when in the week it hits and bring the pattern rather than a guess.
Plateaus, muscle & stopping
My weight loss stalled — what now?
A plateau is one of the most predictable phases of treatment rather than a failure: loss front-loads early and slows as your body needs fewer calories at a lower weight. Check protein, dose consistency and your non-scale trend before assuming the drug stopped.
Will I regain the weight if I stop?
Some of it, usually. Appetite suppression is an ongoing drug effect rather than a permanent reset, so it fades as the drug clears — which is physiology, not a willpower failure. The guide covers what the trial follow-up actually measured, and over what period.
How do I taper off semaglutide?
Slowly, and with your prescriber. One thing worth knowing before you start: you generally cannot jump back to your old top dose if the taper does not hold. The Wegovy label instructs reinitiating dose escalation at a lower dosage after missed consecutive doses. (Wegovy US prescribing information)
Does Mounjaro or Ozempic protect more muscle?
The trials were never designed to compare them. In SURMOUNT-1 roughly a quarter of the weight lost on tirzepatide was lean mass; in STEP 1 it was about 40% — but STEP 1’s placebo group also lost around a quarter, so that gap is not a clean drug effect. (SURMOUNT-1; STEP 1)
Is Shotsy worth it?
It depends what you need tracked. Shot loggers handle doses, weight and side effects well. What none of them shows you is body composition — whether what you are losing is fat or muscle — which is the thing that decides how the weight comes back.
Run the number instead of reading about it
Some of these questions are arithmetic, not reading. The free GLP-1 calculators answer them in one number, with no signup:
Every guide
24 guides, newest first.
How we write about GLP-1 medications
Everything here concerns prescription medicines and people's health, so it is worth being explicit about where the numbers come from and where they stop.
Dosing facts come from the labels, not from other articles. Dose ladders, missed-dose windows, half-lives and adverse-reaction rates are taken from the current prescribing information — Zepbound, Mounjaro, Ozempic and Wegovy via DailyMed in the US, and the Summary of Product Characteristics via the electronic Medicines Compendium in the UK. Where the US and UK differ, and on several points they genuinely do, the article says which one it is quoting. Efficacy figures come from the pivotal trials themselves — STEP, SURMOUNT, SURPASS — cited by author, journal and year so you can open them.
Where the evidence runs out, we say so. Several questions people ask most often have no good answer yet: how quickly appetite returns after stopping, whether tapering beats stopping outright, what a compounded vial actually contains. On those, an honest "this has not been measured" is more useful than a confident number, and you will find that stated rather than papered over.
Clinically reviewed where it counts. Articles covering dosing, side effects and stopping carry a named medical reviewer and the date they reviewed it, shown at the top of the page. A missing byline means exactly what it looks like — that piece has not been through review yet.
None of it is medical advice. No article here can tell you what your dose should be, whether to titrate, or whether to stop. Tiro is a tracking companion, not a treatment. The point of publishing the arithmetic and the sources is that your conversation with your prescriber can start from the same numbers they are working from.
Found something wrong? Tell us at support@tiroglp1.app and we will correct it. Corrections to clinical claims are made in the article itself, not quietly deleted.
Last updated 5 August 2026. The answers above are re-checked against the current prescribing information whenever a label changes.