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The medicines

How long tirzepatide stays in your system

Tirzepatide lasts a little less long than semaglutide, but it is still a once-a-week medicine for the same reason: a fatty-acid chain that keeps it bound to albumin in the blood. Here is what the label says about its half-life, and what that means in the weeks after a dose.

By the Cafeity teamUpdated 4 min read

The short answer

Tirzepatide has an elimination half-life of about 5 to 6 days in people with overweight or obesity.1 That means roughly 40% of the level at your last dose remains after a week, about 15% after two weeks and a few percent after four; after five half-lives — about 25 to 30 days — around 3% is left. It reaches its peak about 24 hours after an injection and a steady level after about 4 weeks of weekly doses.1

Line chart of the share of tirzepatide remaining after the last dose over 35 days: about 38% at 7 days, 14% at 14 days, 5% at 21 days and 2% at 28 days. A dashed semaglutide line for comparison falls more slowly.
Estimated share of the level at the last dose remaining, from the label half-lives (tirzepatide about 5 days; semaglutide about 7 days, dashed). A population model, not a blood test.

What the label says

≈ 5–6 dayselimination half-life (weight-management label; about 5 days in the diabetes label)
≈ 24 hoursmedian time to peak after an injection (range 8 to 72 hours)
≈ 4 weeksof weekly doses to reach a steady level
80%of an injected dose reaches the circulation

Source: the tirzepatide prescribing information, clinical pharmacology section.12

Unlike semaglutide's label, tirzepatide's does not give a "present for N weeks" figure. The five-half-life rule of thumb puts it at roughly 25 to 30 days — a little under a month — after the last dose.

Day by day after the last dose

Using the label range of 5 to 6 days, and 5 days for the central estimate:

Share of the medicine level at your last dose still present after each interval, from a 5-day half-life with simple first-order elimination. It applies to a single dose and to the level after regular dosing alike. A population estimate: individual clearance varies.
Days after the last doseRemaining (estimate)Range (t½ 5–6 days)
187%89% – 87%
276%79% – 76%
366%71% – 66%
550%56% – 50%
738%45% – 38%
1025%31% – 25%
1414%20% – 14%
215.4%8.8% – 5.4%
282.1%3.9% – 2.1%
350.8%1.8% – 0.8%
420.3%0.8% – 0.3%
490.1%0.3% – 0.1%

The shorter half-life compared with semaglutide means a larger swing within each week: on regular weekly doses, the level just before the next injection is around 38% of the peak, against about 50% for semaglutide. Some people notice that as appetite returning in the last day or two before their next dose.

When the half-life matters

  • Oral contraceptives. Tirzepatide delays stomach emptying, which can affect the absorption of medicines taken by mouth. Its patient information says people using birth control pills may be advised to switch to, or add, a non-oral method for 4 weeks after starting and for 4 weeks after each dose increase.1 See contraception and pregnancy.
  • Pregnancy. The label advises stopping tirzepatide when a pregnancy is recognised, and asks patients to tell their healthcare provider if they intend to become pregnant.1
  • Surgery and sedation. Tell every healthcare provider you take tirzepatide before surgery or any procedure involving anaesthesia or deep sedation; the label notes the risk of food entering the lungs.1
  • After stopping. Most of the medicine is gone within about a month, and its effects on appetite and the gut fade over that time.

Why this is an estimate

The half-life is a population average; the label reports a variation of about 20% in clearance between people.1 It does not change meaningfully with sex, body weight, kidney or liver function, according to the label. There is no home test for tirzepatide, and none of this should be used to time a dose — that is for your prescriber and your medicine's own instructions.

Keeping a record of it

Cafeity's Cycle View applies tirzepatide's published half-life to the dose dates you log and draws an estimated level across the week, labelled as an estimate. Log appetite or food noise alongside it and a late-week pattern, if you have one, becomes visible.

Cafeity medication-level chart over seven days, labelled "Estimate based on published half-life. Not a measurement", with the last dose, the injection site (stomach, upper left), the next scheduled dose and a side-effect check-in.
An estimated level from your own dose dates.
Cafeity dose screen: an estimated medication-level curve labelled "Estimate based on published half-life. Not a measurement", the last dose, the injection site (stomach, lower left), a countdown to the next scheduled dose and a side-effect check-in.
The dose record the curve is built from.

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Common questions

How long does tirzepatide stay in your system after stopping?
Its half-life is about 5 to 6 days, so after five half-lives — roughly 25 to 30 days — about 3% of the last level remains.1 The label does not give a single "weeks to clear" figure.
What is the half-life of tirzepatide?
About 5 to 6 days in people with overweight or obesity, according to the weight-management label; the diabetes label gives about 5 days.12
How long after a tirzepatide injection is the level highest?
A median of about 24 hours, with a range of 8 to 72 hours.1
Does tirzepatide leave the body faster than semaglutide?
Yes, a little: about 5 to 6 days' half-life against about a week, so it clears in roughly a month rather than 5 to 7 weeks.13

Sources

  1. Tirzepatide injection for weight management and obstructive sleep apnoea — US prescribing information DailyMed, US National Library of Medicine, version published 2 September 2026
  2. Tirzepatide injection for type 2 diabetes — US prescribing information DailyMed, US National Library of Medicine, version published 2 September 2026
  3. Semaglutide injection and tablets for weight management — US prescribing information DailyMed, US National Library of Medicine, version published 30 June 2026

Written by the Cafeity team from the sources listed here. Figures from prescribing information are quoted as the label states them; trial results are averages from those trials, not predictions for any one person. This page has not yet been reviewed by a clinician — see the editorial policy for how pages are researched and corrected.