Half the dosing questions I am sent are not really dosing questions. They are people trying to work out whether they are behind.
Someone hears that a colleague is “on the 10”, reads that the maximum is 15, does the arithmetic, and concludes they are being under-treated at 5 mg. None of those numbers mean anything without knowing which drug, which indication, and how long the person has been climbing.
Semaglutide: Ozempic and Wegovy
Same molecule, two licences, two different ceilings. Ozempic is approved for type 2 diabetes and cardiovascular risk reduction; Wegovy is approved for weight management and, since 2024, for cardiovascular risk reduction in people with obesity and established heart disease.
| Step | Ozempic | Wegovy | Minimum time at step |
|---|---|---|---|
| 1 | 0.25 mg | 0.25 mg | 4 weeks |
| 2 | 0.5 mg | 0.5 mg | 4 weeks |
| 3 | 1.0 mg | 1.0 mg | 4 weeks |
| 4 | 2.0 mg (max) | 1.7 mg | 4 weeks |
| 5 | — | 2.4 mg (max) | maintenance |
The earliest anyone reaches the top of the Wegovy ladder is week seventeen. That is worth sitting with, because it reframes almost every “is this working yet” question asked before month five. I have written separately about how long Wegovy takes to work, and the escalation schedule is most of the answer.
There is also Rybelsus, oral semaglutide, dosed daily rather than weekly: 3 mg for 30 days, then 7 mg, then 14 mg. The 3 mg dose is explicitly not effective for glycaemic control — it exists purely to let the gut adapt. A higher-dose oral semaglutide for obesity is a separate product with its own ladder — see the obesity pill — and orforglipron is a different molecule entirely.
Tirzepatide: Mounjaro and Zepbound
Here the two brands share an identical ladder. The difference is indication and, in practice, insurance.
| Step | Dose | Minimum time at step | Notes |
|---|---|---|---|
| 1 | 2.5 mg | 4 weeks | Tolerance only — not a treatment dose |
| 2 | 5 mg | 4 weeks | First maintenance option for Zepbound |
| 3 | 7.5 mg | 4 weeks | Intermediate |
| 4 | 10 mg | 4 weeks | Second maintenance option |
| 5 | 12.5 mg | 4 weeks | Intermediate |
| 6 | 15 mg | maintenance | Maximum |
Zepbound is licensed with three maintenance doses — 5, 10 and 15 mg — and 7.5 and 12.5 mg are formally described as intermediate steps. This is the single most misunderstood thing about tirzepatide dosing. Stopping at 5 mg is not stopping early. It is one of the three destinations the drug was licensed to reach.
Why the ladder exists at all
Two reasons, and they are different.
The first is gastrointestinal tolerance. These drugs slow gastric emptying, and the gut adapts to that over weeks. Start at a therapeutic dose and a large fraction of people vomit their way off the medication in a fortnight.
The second is pharmacokinetic and gets ignored. Semaglutide has a half-life of about a week, tirzepatide about five days. After any dose change, blood levels need roughly four to five weeks to reach a new steady state. So the dose you took a month ago is the one you are feeling now. Judging a step at day ten is judging something that has not finished arriving.
4 weeks
Minimum interval between dose increases for all four injectables
~7 days
Half-life of semaglutide — roughly 5 days for tirzepatide
17 weeks
Earliest possible arrival at the top Wegovy dose
Missed doses and moving your injection day
The rules differ between the two molecules, which is a genuinely common source of error.
Semaglutide (Ozempic, Wegovy). If you remember within five days, take it and carry on with your usual day. Past five days, skip it. You may change your injection day provided there are at least 48 hours between doses.
Tirzepatide (Mounjaro, Zepbound). The catch-up window is four days, not five. You may change your injection day provided there are at least 72 hours between doses.
If you have missed several consecutive weeks, do not simply resume at your old dose. Tolerance fades faster than people expect, and restarting at 12.5 mg after a month off is a reliable way to spend a weekend on the bathroom floor. Most clinicians will step you back down and re-escalate; the detail is in what to do about a missed dose.
The escalation schedule is a ceiling, not a target. Nobody wins a prize for reaching 15 milligrams.
Where the chart stops being useful
Dose charts describe licensed products. They do not describe a large and growing share of what Americans are actually injecting.
Compounded semaglutide and tirzepatide are frequently dosed in units or millilitres rather than milligrams, on schedules invented by the prescribing platform. A “20 units” instruction is meaningless without the concentration of the vial, and concentrations vary between compounders. If you cannot state your dose in milligrams, you do not know your dose — which matters enormously the day you end up in an emergency department or switch to a licensed product. Deliberately sub-therapeutic dosing has its own following, examined in microdosing a GLP-1.
The number that actually matters
Not the dose. The trajectory.
A person doing well at 5 mg of tirzepatide is doing better than a person struggling at 15 mg, and the ladder has no opinion about which of them is winning. The only reason to climb is that you have stopped getting what you came for at the rung you are on.