A once-weekly dual GIP and GLP-1 receptor agonist with large phase 3 programs and regulated indications for type 2 diabetes and chronic weight management.
Tirzepatide uses a regulator-defined escalation ladder. The calculator preset mirrors the 2.5 mg initiation amount, not the maintenance doses tested for long-term outcomes. This is educational source context, not a protocol or recommendation.
Used to start treatment and improve tolerability.
The first maintenance level; further increases are based on response and tolerability.
SURMOUNT-1 tested 5, 10, and 15 mg maintenance arms.
Do not translate an approved pen dose into research-vial units without verifying concentration and formulation.
The clinical formulation is designed for weekly use.
Escalation generally occurs no more frequently than every four weeks.
Follow current labeling for missed doses, interruptions, and contraindications.
Weekly doses from 5 to 15 mg have extensive phase 3 data after gradual escalation.
Keep cold, dry, and protected from light according to the manufacturer certificate or validated lab SOP.
Use sterile technique, refrigerate as validated, and avoid repeated freeze-thaw cycles.
Record lot, concentration, preparation date, and the identity/purity documentation used by the lab.
What published studies and recent community write-ups report about amounts, timing and course length. 9 clinical and 4 community-reported rows, each linked to its source. These are descriptions of what others report, not instructions, and nothing here is medical advice.
| Context | Dose | Frequency | Route | Course | Source |
|---|---|---|---|---|---|
| Clinical9 rows | |||||
| FDA label, Zepbound (weight management and obstructive sleep apnea)Adults with obesity, or overweight with a weight-related condition; adults with moderate to severe OSA and obesity | 2.5 mg to start; maintenance 5, 10 or 15 mg (weight), 10 or 15 mg (OSA); 15 mg maximum | Once weekly, increasing by 2.5 mg after at least 4 weeks on the current dose | Subcutaneous, abdomen, thigh or upper arm, rotating sites; single-dose pens or vials (0.5 mL) and a multi-dose KwikPen | Continuous; 2.5 mg is for initiation only and is not an approved maintenance doseNone; a missed dose is taken within 4 days or skipped | DailyMed, National Library of Medicine2026 |
| The label fixes the escalation ladder (2.5, 5, 7.5, 10, 12.5, 15 mg) with four weeks minimum per step to limit nausea, vomiting, diarrhea and constipation, and asks prescribers to pick a maintenance dose on response and tolerability. It reports a half-life of 5 to 6 days, peak levels about 24 hours after injection, 80% bioavailability, and carries a boxed warning for thyroid C-cell tumors with a contraindication in medullary thyroid carcinoma or MEN 2. | |||||
| FDA label, Mounjaro (type 2 diabetes)Adults and children aged 10 and older with type 2 diabetes | 2.5 mg for 4 weeks, then 5 mg; further 2.5 mg steps as needed; 15 mg maximum in adults, 10 mg in children | Once weekly, at any time of day, with or without food | Subcutaneous, abdomen or thigh, or the back of the upper arm when injected by someone else | ContinuousNone; a missed dose is taken within 96 hours or skipped, and the weekly day can change if doses stay at least 72 hours apart | DailyMed, National Library of Medicine2026 |
| The July 2026 revision adds pediatric patients from age 10 with a lower 10 mg ceiling and keeps the adult ladder unchanged. Acute gallbladder disease occurred in 0.6% of treated adults versus none on placebo, and injection site reactions and hypersensitivity were more common in the roughly half of patients who developed anti-tirzepatide antibodies. | |||||
| Phase 1 and 1b dose ranging (with mouse pharmacology)142 healthy adults and adults with type 2 diabetes | Single doses of 0.25-8 mg; repeat doses of 0.5-10 mg (healthy) and 0.5-15 mg (diabetes), doses above 5 mg reached by titration | Once weekly | Subcutaneous | 4 weeks of repeat dosingNot applicable | Molecular Metabolism (PubMed)2018 |
| The pharmacokinetics supported weekly dosing, 10 and 15 mg cut fasting glucose by 43-49 mg/dL versus placebo in diabetic patients within four weeks, and healthy volunteers lost up to 5.1 kg at 4.5 mg. Vomiting, nausea, reduced appetite and diarrhea were the main side effects; the same paper reports that chronic dosing in mice cut weight and food intake more than a GLP-1 agonist alone. | |||||
| SURPASS-2 versus semaglutide in type 2 diabetes1,879 adults with type 2 diabetes on metformin, mean HbA1c 8.28% | 5, 10 or 15 mg (versus semaglutide 1 mg) | Once weekly | Subcutaneous | 40 weeksNone | New England Journal of Medicine (PubMed)2021 |
| HbA1c fell 2.01, 2.24 and 2.30 percentage points on 5, 10 and 15 mg against 1.86 on semaglutide, and weight fell 1.9, 3.6 and 5.5 kg more than with semaglutide. Gastrointestinal events were similar in kind and frequency to semaglutide, and glucose below 54 mg/dL occurred in 0.2-1.7% of tirzepatide patients. | |||||
| SURMOUNT-1 in obesity without diabetes2,539 adults with a BMI of 30 or more, or 27 or more with a complication, mean weight 104.8 kg | 5, 10 or 15 mg | Once weekly | Subcutaneous | 72 weeks, including a 20-week escalation periodNone | New England Journal of Medicine (PubMed)2022 |
| Weight fell 15.0%, 19.5% and 20.9% on 5, 10 and 15 mg versus 3.1% on placebo, and 50-57% of the two higher-dose groups lost at least a fifth of their body weight. Adverse events led 4.3%, 7.1% and 6.2% of the tirzepatide groups to stop, against 2.6% on placebo, mostly for gut symptoms during escalation. | |||||
| SURMOUNT-2 in obesity with type 2 diabetes938 adults with a BMI of 27 or more and HbA1c 7-10% | 10 or 15 mg | Once weekly | Subcutaneous | 72 weeksNone | The Lancet (PubMed)2023 |
| Weight fell 12.8% and 14.7% versus 3.2% on placebo, smaller losses than in people without diabetes, with 79-83% reaching a 5% reduction. Fewer than 5% stopped for adverse events and serious adverse events were reported by 7% overall. | |||||
| SURMOUNT-4 randomized withdrawal783 adults with obesity entered a 36-week lead-in; 670 were randomized to continue or switch to placebo | Maximum tolerated dose of 10 or 15 mg | Once weekly | Subcutaneous | 36 weeks open-label, then 52 weeks randomized (88 weeks total)Half of participants were switched to placebo at week 36 | JAMA (PubMed)2024 |
| After losing 20.9% in the lead-in, those who continued lost a further 5.5% while those switched to placebo regained 14.0% over 52 weeks, and 89.5% versus 16.6% kept at least four fifths of their initial loss. This is the clearest evidence that stopping tirzepatide reverses most of its effect within a year. | |||||
| SURMOUNT-OSA in obstructive sleep apnea with obesity469 adults with moderate to severe OSA and obesity, with or without PAP therapy | Maximum tolerated dose of 10 or 15 mg | Once weekly | Subcutaneous | 52 weeks, with escalation over up to 20 weeksNone | New England Journal of Medicine (PubMed)2024 |
| The apnea-hypopnea index fell by 25.3 and 29.3 events per hour in the two trials versus about 5 on placebo, with improvements in hypoxic burden, blood pressure, C-reactive protein and sleep questionnaires. These results underpin the OSA indication added to the Zepbound label. | |||||
| SURMOUNT-5 head to head with semaglutide751 adults with obesity or overweight plus a weight-related condition, without diabetes | Maximum tolerated dose of 10 or 15 mg (versus semaglutide 1.7 or 2.4 mg) | Once weekly, escalating every 4 weeks | Subcutaneous | 72 weeksNone | New England Journal of Medicine (PubMed)2025 |
| Weight fell 20.2% on tirzepatide versus 13.7% on semaglutide and waist circumference by 18.4 versus 13.0 cm, with more tirzepatide patients reaching every threshold from 10% to 25%. The trial was open-label, and gastrointestinal effects clustered during escalation in both arms. | |||||
| Community-reported4 rows | |||||
| Telehealth compounding chart (10 and 20 mg/mL kits) | 2.5 mg (25 units at 10 mg/mL; 12.5 units at 20 mg/mL) rising to 15 mg (75 units at 20 mg/mL) | Once weekly, 4 weeks per step | Subcutaneous from compounded vials, pre-mixed or reconstituted with bacteriostatic water, using a U-100 insulin syringe | Same ladder as the label: 2.5, 5, 7.5, 10, 12.5, 15 mgNone described | Community resource2026 |
| A telehealth provider's 2026 chart explains that starter kits are usually 10 mg/mL so the 2.5 and 5 mg draws are readable, and that patients switch to 20 mg/mL once they pass 10 mg so a dose fits in a 1 mL syringe. It states the schedule follows the Zepbound and Mounjaro labels and the SURMOUNT-1 protocol. | |||||
| Label-anchored conversion tables for compounded vials | 2.5-15 mg; volume = dose divided by concentration (0.125-3 mL depending on 5, 10 or 20 mg/mL) | Once weekly, increases only after at least 4 weeks at the current dose | Subcutaneous from compounded vials | Open-ended; maintenance at 5, 10 or 15 mgNone described | Community resource2026 |
| This 2026 guide reproduces the Zepbound ladder and points out that 7.5 and 12.5 mg are escalation steps rather than listed weight-management maintenance doses, and that reaching 15 mg is not automatic. It frames syringe units as a scale conversion rather than a biological unit and defers the regimen to the prescriber. | |||||
| Vendor chart across five vial concentrations | 2.5 mg weeks 1-4, 5 mg weeks 5-8, 7.5 mg weeks 9-12, 10 mg weeks 13-16, 12.5 mg weeks 17-20, then 15 mg | Once weekly, 4 weeks minimum per step | Subcutaneous from 5, 10, 15, 17 or 20 mg/mL vials (2.5 mg = 50, 25, 16.7, 14.7 or 12.5 units) | 20 weeks to the top dose, then maintenance at any tolerated stepNone described | Community resource2026 |
| A peptide vendor's 2026 article tabulates unit counts for every step at each concentration and warns that 12.5 units at 20 mg/mL is hard to measure on a standard insulin syringe. It calls the 2.5 mg start an acclimation dose rather than a therapeutic one and tells readers not to escalate early even if they feel fine. | |||||
| Telehealth explainer on brand versus compounded dosing | 2.5 mg, then 5, 7.5, 10, 12.5 and 15 mg | Once weekly, never increased sooner than every 4 weeks | Subcutaneous; brand pens and vials hold 0.5 mL per dose, compounded concentrations vary | Continuous under prescriber reviewNone described | Community resource2026 |
| This 2026 guide stresses that a figure like 25 units means nothing without the vial concentration and that compounded products may differ from the brand in excipients and strength. It lists the brand presentations, including multi-dose KwikPens of four 0.6 mL doses, so patients can match what they hold to the label. | |||||
Every label and trial starts at 2.5 mg once weekly for four weeks. The label calls this an initiation dose, not a maintenance dose, and most gastrointestinal effects appear during this and the following escalation steps.
The first step up and the lowest approved maintenance dose for weight management and diabetes. In SURMOUNT-1 staying at 5 mg produced 15.0% weight loss at 72 weeks with the lowest rate of discontinuation among the active arms.
Further 2.5 mg steps every four weeks reach 10 mg by week 12 and 15 mg by week 20, which is the escalation used in the phase 3 trials. The label asks prescribers to settle on 5, 10 or 15 mg according to response and tolerability rather than climbing to the maximum by default.
Weight continued to fall through week 72 in SURMOUNT-1 and SURMOUNT-5, reaching about 20% on the two higher doses, and HbA1c reductions in the SURPASS trials were measured at 40 weeks. There is no planned end to treatment in any label.
In SURMOUNT-4, people switched to placebo after 36 weeks regained 14% of body weight over the next year while those who continued lost a further 5.5%. No label describes a taper, and the 5 to 6 day half-life means the drug is largely gone within about four weeks of the last dose.
Compounding and vendor charts reproduce the same ladder but express each step in syringe units that depend on the vial's concentration, commonly 10 mg/mL for starting doses and 20 mg/mL for maintenance. A unit count copied from a different concentration delivers the wrong dose, which the charts themselves flag as the main risk.
Plus 4 community resources (dosing guides, forum threads and vendor write-ups), reported above but not linked.
Tirzepatide (LY3298176) is a once-weekly injectable peptide that activates both the GIP and GLP-1 receptors, a 39-amino-acid analog with a C20 fatty diacid side chain that binds albumin and gives it a half-life of 5 to 6 days. The FDA approved it in 2022 as Mounjaro for type 2 diabetes, then as Zepbound for chronic weight management and for moderate to severe obstructive sleep apnea in adults with obesity; the 2026 Mounjaro label also covers children from age 10. In the phase 3 program it lowered HbA1c by about 2 percentage points and beat semaglutide 1 mg in SURPASS-2, produced 20.9% mean weight loss at 72 weeks on 15 mg in SURMOUNT-1, and out-performed semaglutide 2.4 mg head to head in SURMOUNT-5. Both labels carry a boxed warning for thyroid C-cell tumors seen in rodents, and compounded or grey-market vials sold at concentrations from 5 to 20 mg/mL account for most of the dosing confusion documented online.
These themes describe recurring questions in published research. They are not claims of effectiveness or recommendations for use.
SURMOUNT trials evaluate weekly 5, 10, and 15 mg maintenance doses after escalation.
SURPASS trials examine glycaemic outcomes across a range of comparators.
Longer follow-up evaluates progression from prediabetes in participants with obesity.
Gastrointestinal events cluster during dose escalation and are dose-dependent.
Study models remain visible so laboratory and animal findings are not mistaken for established human outcomes.
A 72-week randomized trial compared weekly 5, 10, and 15 mg doses with placebo in 2,539 adults without diabetes.
A prespecified population with obesity and prediabetes was followed through 176 weeks of treatment.
The 2.5 mg initiation step is followed by 2.5 mg increments when clinically appropriate.
These amount records are independent from vial strength, reconstitution volume and measuring device. A recorded source is not the same as study backing, and these values are not recommendations.
Sequence, synonyms and registry identifiers as recorded in PubChem, the National Library of Medicine's open chemistry database. Formula, mass and CAS number are summarized at the top of the page.
Tyr-Aib-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Tyr-Ser-Ile-Aib-Leu-Asp-Lys-Ile-Ala-Gln-Lys(C20 diacid-gamma-Glu-AEEA-AEEA)-Ala-Phe-Val-Gln-Trp-Leu-Ile-Ala-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2
Zepbound, Mounjaro, LY3298176, Tirzepatide [INN, USAN], UNII OYN3CCI6QE, GTPL11429, BG-121, CAS 2023788-19-2 (listed on PubChem's other tirzepatide records, for example CID 166567236)
AAPYRSPHYSKGIS-MCNPHUAVSA-N
Engineered from the native GIP sequence with GLP-1 receptor activity
(2S)-2-[[20-[[(5S)-6-[[(2S,3S)-1-[[(2S)-1-[[(2S)-5-amino-1-[[(2S)-6-amino-1-[[(2S)-1-[[(2S)-1-[[(2S)-1-[[(2S)-5-amino-1-[[(2S)-1-[[(2S)-1-[[(2S,3S)-1-[[(2S)-1-[[2-[[2-[(2S)-2-[[(2S)-1-[[(2S)-1-[[2-[[(2S)-1-[(2S)-2-[(2S)-2-[(2S)-2-[[(2S)-1-amino-3-hydroxy-1-oxopropan-2-yl]carbamoyl]pyrrolidine-1-carbonyl]pyrrolidine-1-carbonyl]pyrrolidin-1-yl]-1-oxopropan-2-yl]amino]-2-oxoethyl]amino]-3-hydroxy-1-oxopropan-2-yl]amino]-3-hydroxy-1-oxopropan-2-yl]carbamoyl]pyrrolidin-1-yl]-2-oxoethyl]amino]-2-oxoethyl]amino]-1-oxopropan-2-yl]amino]-3-methyl-1-oxopentan-2-yl]amino]-4-methyl-1-oxopentan-2-yl]amino]-3-(1H-indol-3-yl)-1-oxopropan-2-yl]amino]-1,5-dioxopentan-2-yl]amino]-3-methyl-1-oxobutan-2-yl]amino]-1-oxo-3-phenylpropan-2-yl]amino]-1-oxopropan-2-yl]amino]-1-oxohexan-2-yl]amino]-1,5-dioxopentan-2-yl]amino]-1-oxopropan-2-yl]amino]-3-methyl-1-oxopentan-2-yl]amino]-5-[[(2S)-2-[[(2S)-2-[[2-[[(2S,3S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S,3R)-2-[[2-[[(2S)-2-[[2-[[(2S)-2-amino-3-(4-hydroxyphenyl)propanoyl]amino]-2-methylpropanoyl]amino]-4-carboxybutanoyl]amino]acetyl]amino]-3-hydroxybutanoyl]amino]-3-phenylpropanoyl]amino]-3-hydroxybutanoyl]amino]-3-hydroxypropanoyl]amino]-3-carboxypropanoyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-3-hydroxypropanoyl]amino]-3-methylpentanoyl]amino]-2-methylpropanoyl]amino]-4-methylpentanoyl]amino]-3-carboxypropanoyl]amino]-6-oxohexyl]amino]-20-oxoicosanoyl]amino]-5-[2-[2-[2-[2-[2-(carboxymethoxy)ethoxy]ethylamino]-2-oxoethoxy]ethoxy]ethylamino]-5-oxopentanoic acid
2 curated references, each with its journal, year and study model, plus 4 community resources reported but not linked.