What is the standard tirzepatide dosage schedule?

2.5 mg once weekly for the first four weeks, then 5 mg, with further increases of 2.5 mg at intervals of at least four weeks through 7.5 mg, 10 mg and 12.5 mg, to a maximum of 15 mg weekly. The 2.5 mg starting dose is for initiation only. Recognised maintenance doses for weight reduction are 5 mg, 10 mg and 15 mg.

Why do you have to wait four weeks between tirzepatide dose increases?

Tirzepatide has a half-life of about five days, so blood levels take roughly four to five weeks to plateau after a change. Increasing sooner stacks a higher dose on levels that are still rising, producing side effects before the current dose has shown what it can do. Four weeks is a minimum interval, not a required pace.

Do I have to reach 15 mg of tirzepatide?

No. In SURMOUNT-1, average weight reduction was 15.0% at 5 mg, 19.5% at 10 mg and 20.9% at 15 mg — the gains shrink as the dose climbs while side effects keep rising. The aim is the lowest dose achieving your goal at a tolerable burden, which is a decision for you and your prescriber.

Why is my compounded tirzepatide dose written in units instead of milligrams?

Compounded vials are prepared at a concentration the pharmacy sets, and instructions are often written in units on an insulin syringe. Units measure volume, not drug — the same units drawn from two differently concentrated vials are not the same dose. Never convert from a chart online; get the conversion from your prescriber or dispensing pharmacy.

What should I do if I miss a tirzepatide dose?

Labeled guidance for the reference product is to take it as soon as possible within four days of the missed dose. Beyond four days, skip it and resume on your regular day — do not double up. If you have missed several weeks, contact your prescriber rather than restarting at your previous dose, since tolerance falls as levels drop.

Can my tirzepatide dose be increased faster than every four weeks?

The labeled interval is a minimum, and going faster is not standard practice — it front-loads side effects without a corresponding benefit. Deviations from the ladder are far more often downward: holding at a dose longer, stepping back, or moving up in smaller increments are ordinary strategies for tolerability.

Tirzepatide Dosage and the Titration Ladder

Tirzepatide dosage follows a titration ladder: 2.5 mg once weekly to start, then increases of 2.5 mg at intervals of at least four weeks, up to a maximum of 15 mg weekly. Some prescribers move in smaller increments than that ladder — the practice usually called microdosing. The starting dose is for initiation only and is not a maintenance dose. The four-week interval is not arbitrary — it is roughly how long the drug takes to reach steady state in your blood.

The standard tirzepatide dosage ladder

The branded reference product's labeled schedule is the template every prescriber works from:

Weeks	Dose (once weekly)	Purpose
1–4	2.5 mg	Initiation only — not a maintenance dose
5–8	5 mg	First maintenance option
9–12	7.5 mg	Escalation step
13–16	10 mg	Maintenance option
17–20	12.5 mg	Escalation step
21+	15 mg	Maximum dose

Three of those rungs — 5 mg, 10 mg and 15 mg — are recognised maintenance doses for weight reduction. The other two are waypoints you pass through on the way up. Nobody is required to climb to the top: the goal is the lowest dose that gets the result you and your prescriber are aiming for, at a side-effect burden you can live with.

Why four weeks between increases

Tirzepatide has a half-life of about five days. That means after a dose change it takes roughly four to five weeks for blood levels to plateau at the new concentration. Increase sooner and you are stacking a higher dose on top of levels that have not finished rising — you get the side effects of the new dose before you have seen what the current one actually does.

The four-week interval is a floor, not a schedule. A prescriber can hold you at a dose for eight weeks or twelve if that is where you are comfortable and progressing.

What the dose actually buys you

In SURMOUNT-1, the 72-week trial in 2,539 adults with obesity or overweight, average weight reduction was 15.0% at 5 mg, 19.5% at 10 mg and 20.9% at 15 mg, against 3.1% on placebo (Jastreboff et al., NEJM 2022).

Notice the shape of that curve. Doubling from 5 mg to 10 mg added about 4.5 percentage points; going from 10 mg to 15 mg added about 1.4. Side effects, meanwhile, keep climbing with dose — gastrointestinal adverse events ran 39% at 5 mg, 46% at 10 mg and 49% at 15 mg, and discontinuation for adverse events reached about 10% at the top dose (Mishra et al., J Endocr Soc 2023).

That is the whole argument for not treating 15 mg as the destination. More dose is not automatically more benefit, and it is reliably more side effect. We cover the full picture in tirzepatide side effects.

Compounded tirzepatide is dosed by your prescriber, not by a chart

Through Promise, tirzepatide is dispensed as a compounded medication, which is different from an FDA-approved product: the formulation offered here — tirzepatide with vitamin B12 — is not FDA-approved. The dosing research above comes from trials of the molecule itself.

This matters practically. A compounded vial is prepared at a concentration the pharmacy sets, so your instructions may be written in units on an insulin syringe rather than in milligrams. Units are a measure of volume, not of drug — the same number of units from two differently concentrated vials is not the same dose. That is exactly why the conversion is not something to work out from a chart you found online.

Your prescriber writes the dose, the schedule, and the escalation plan based on your medical history, what you are taking it for, and how you tolerate it. If anything about your instructions is unclear, the answer comes from them or the dispensing pharmacy.

Slowing down is a normal strategy

The most common reason to deviate from the standard ladder is tolerability, and the deviation is almost always downward. Extending time at a dose, stepping back to the last one that felt manageable, or moving up in a smaller increment are ordinary clinical strategies — not evidence that treatment is failing.

Side effects are front-loaded around each increase. If the days after a step-up are consistently rough, that is information your prescriber can act on.

Missing a dose

The labeled guidance for the reference product is to take a missed dose as soon as possible within four days. If more than four days have passed, skip it and resume on the regular day. Do not double up to catch up.

If you miss several weeks, do not simply restart where you left off — blood levels have fallen, and your tolerance along with them. That is a conversation with your prescriber, who may restart you lower.

Practical dosing details

Tirzepatide is injected subcutaneously once weekly, on the same day each week, at any time of day, with or without food. You can change which day you take it as long as at least three days separate doses. Rotating injection sites — abdomen, thigh, upper arm — is standard practice.

How dosing decisions get made at Promise

Every request goes to a licensed provider in Promise's prescriber network, who reviews your history and prescribes only when tirzepatide is appropriate for you — or declines. Not everyone qualifies. The starting dose and the escalation plan come out of that review, and follow-up check-ins are part of the service rather than an upsell.

If you are still choosing between options, the metabolic support and fat loss hub covers what else is available, and tirzepatide versus semaglutide compares the two most common starting points.