October 12, 2026 · By the ShopMedRx team
Tirzepatide Dosage Chart: Starting Dose, Steps and Units
A plain-language tirzepatide dosage chart: the labeled starting dose, step-ups every 4 weeks, how units work, missed doses and safety. For adults 18+.
A tirzepatide dosage chart starts with one fixed point: the labeled starting dose is 2.5 mg injected once a week for 4 weeks, then raised in 2.5 mg steps no sooner than every 4 weeks, up to a 15 mg weekly maximum.[1] Your own schedule is set by a licensed clinician, who may move more slowly or stop at a lower dose. This guide walks through each step, explains how dosing "in units" works, and covers missed doses and safety.
By the ShopMedRx team. This article is general education for adults 18 and older and is not medical advice.
Tirzepatide dosage chart: the labeled step-up schedule
The chart below is a reference schedule taken from the FDA label for tirzepatide injection for weight management. The label says to start at 2.5 mg once weekly for 4 weeks, then increase in 2.5 mg steps after at least 4 weeks on each dose, until a maintenance dose is reached.[1][2] The "earliest week" column shows the soonest a step can happen on that plan. It is a minimum, not a target.
| Step | Weekly dose | Earliest week to start | What it is |
|---|---|---|---|
| 1 | 2.5 mg | Week 1 | Starting dose, for the first 4 weeks |
| 2 | 5 mg | Week 5 | Possible maintenance dose |
| 3 | 7.5 mg | Week 9 | Step-up dose |
| 4 | 10 mg | Week 13 | Possible maintenance dose |
| 5 | 12.5 mg | Week 17 | Step-up dose |
| 6 | 15 mg | Week 21 | Maximum weekly dose |
Two things this chart does not tell you. First, it is not a prescription. Whether tirzepatide is appropriate, and which dose, depends on a clinician's review of your health history. Second, our tirzepatide injections are compounded medications. Compounded drugs are not FDA-approved, and the FDA does not review them for safety, effectiveness or quality before they are marketed.[4] For a compounded prescription, the prescribing clinician decides the schedule, and it may differ from the table above. Your pharmacist can explain the directions on your own label.
Starting dose of tirzepatide: why 2.5 mg is only the beginning
The starting dose of tirzepatide, 2.5 mg, is meant to help your body get used to the medicine. The label describes it as the initial dose, followed by increases of 2.5 mg after at least 4 weeks.[1] It is not listed as a maintenance dose for weight management.[2]
Starting low and moving up gradually is called titration. Stomach side effects such as nausea, diarrhea, vomiting and constipation are among the most commonly reported with tirzepatide, which is one reason doses are raised in small steps.[1] If a step feels rough, a clinician may hold you at the current dose longer before the next increase. Do not change your dose on your own.
Maintenance dose: 5 mg, 10 mg or 15 mg
For weight management, the labeled maintenance doses are 5 mg, 10 mg or 15 mg once weekly. For obstructive sleep apnea, the labeled maintenance doses are 10 mg or 15 mg. The top dose is 15 mg weekly, and the label says to consider response and tolerability when choosing a maintenance dose.[2] That choice is a call for your clinician.
In a 72-week trial of FDA-approved tirzepatide in adults with obesity but without diabetes, the average body-weight change was about 15.0% at 5 mg, 19.5% at 10 mg and 20.9% at 15 mg. Everyone in that trial also received lifestyle counseling. Individual results vary, and these averages do not predict what any one person will experience.[3]
A higher dose is not automatically a better dose. In the same trial, the most common side effects were stomach-related, mostly mild to moderate, and they showed up most often while the dose was being raised.[3]
Is there a "right" dose for everyone?
No. The labeled range exists so clinicians can match the dose to the person. Some people settle at a middle dose. Others go higher. Your clinician looks at tolerability, your other medicines and your health conditions when choosing where to stop.
Tirzepatide dosing for weight loss in units: how the math works
People search for tirzepatide dosing in units because some injectable products come in a vial and are drawn up with a syringe marked in units. Doses are prescribed in milligrams (mg). Units only enter the picture when a vial is measured with a syringe, and the number of units for a given dose depends entirely on the concentration printed on your pharmacy label.
Standard U-100 insulin syringes hold 100 units per milliliter (mL). The math is: dose in mg, divided by the concentration in mg per mL, times 100. The table below uses two made-up concentrations purely to show why one universal "units chart" cannot exist.
| Weekly dose | If the vial is 10 mg/mL | If the vial is 20 mg/mL |
|---|---|---|
| 2.5 mg | 25 units | 12.5 units |
| 5 mg | 50 units | 25 units |
| 10 mg | 100 units | 50 units |
Illustration only. Do not use these numbers to draw up a dose. The same milligram dose is a different number of units at a different concentration, so a chart copied from the internet can put you off by a factor of two or more. Follow the dose, concentration and directions on the label your pharmacy sends. Ask your pharmacist to confirm the unit count, and to show you how to measure it, before your first injection.
This matters because the FDA has raised concerns about compounded GLP-1 products, including dosing errors and the way multi-dose vials are used. It notes that vials holding multiple doses of sterile medicine should generally be used within 28 days of first use because the risk of contamination rises after that.[4] Ask your pharmacist how long your specific vial can be used and how to store it.
Tips for measuring safely
- Check the concentration (mg per mL) on the label every time you start a new vial.
- Write down your prescribed mg dose and the matching unit number on the day you receive it, and have your pharmacist or clinician confirm it.
- Use only the syringes your pharmacy supplies or recommends.
- Do not move to a new dose step and a new vial concentration at the same time without asking first.
- Contact your clinician or pharmacist right away if the numbers on the label and your instructions do not match.
For help with injection technique, spot rotation and storage, ask your pharmacist or clinician, who can show you using your own product.
Missed doses and schedule changes
The label says to use tirzepatide once a week, at any time of day.[1] If you miss a dose, the label says to take it as soon as possible within 4 days (96 hours) after the missed dose. If more than 4 days have passed, skip it and take the next dose on your regular day.[1] You can change your injection day if needed, as long as at least 3 days (72 hours) separate two doses.[1] Those rules come from the FDA-approved product's label, so for a compounded prescription, follow the directions from your prescriber and pharmacist.
If you miss more than one dose, or you have been off the medicine for a while, ask your clinician before restarting at your old dose. A lower restart dose is sometimes chosen, but that decision belongs to your prescriber.
Lower or slower schedules
Some clinicians choose smaller doses or slower step-ups for certain patients. These are decisions for a licensed clinician, and these approaches are outside the labeled schedule. If you are curious, you can read about our tirzepatide microdose injection program, which is also prescribed only if a clinician decides it is appropriate. There is far less published evidence for low-dose approaches than for the labeled schedule, so ask your clinician what to expect.
Safety: side effects and who should not take tirzepatide
Tirzepatide carries a boxed warning, the FDA's strongest warning, about the risk of thyroid C-cell tumors. It should not be used by anyone with a personal or family history of medullary thyroid carcinoma (MTC) or with Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).[2][5] Tell a clinician if you have either.
The label also lists other risks to discuss with a clinician:[1]
- Pancreatitis (inflammation of the pancreas) and gallbladder problems, such as gallstones.
- Low blood sugar, especially if you also take insulin or a sulfonylurea.
- Dehydration from vomiting or diarrhea, which can lead to kidney injury.
- Serious allergic reactions.
- Effects on birth control pills. Tirzepatide lowered the levels of an oral contraceptive in a label study, so ask your clinician whether you need a non-oral or added barrier method.[5]
- Pregnancy: tell your clinician if you are pregnant, planning to become pregnant or breastfeeding.
Call a clinician promptly for severe stomach pain, repeated vomiting, a lump or swelling in the neck, trouble swallowing, or signs of an allergic reaction. If you are wondering what to eat while your dose goes up, see the GLP-1 diet guide. If you are thinking about keeping muscle while on a GLP-1, read creatine and muscle on a GLP-1.
Questions to ask a clinician about your dose
- Which starting dose and step-up timing do you recommend for me, and why?
- What should I do if side effects get worse after a dose increase?
- How will I know when I have reached the right maintenance dose?
- If my medicine comes in a vial, how many units equal each of my doses, and can a pharmacist confirm it?
- How should I store the medicine, how long can a vial be used, and what do I do about a missed dose?
- Do any of my other medicines, including birth control, change the plan?
Our tirzepatide injection program begins with an online health assessment. Independent, licensed clinicians through OpenLoop Health review it and decide whether a prescription is appropriate. If one is prescribed, a licensed U.S. partner pharmacy fills it.
Frequently asked questions
What is the starting dose of tirzepatide?
The labeled starting dose is 2.5 mg injected under the skin once a week for 4 weeks. After that, the label allows increases in 2.5 mg steps after at least 4 weeks on the current dose.[1] A clinician may adjust this plan for you.
How often does the tirzepatide dose go up?
On the labeled schedule, the dose can be raised in 2.5 mg steps after at least 4 weeks on the current dose.[1] That is the fastest allowed pace, and many people stay on a dose longer if their clinician thinks it is wise.
How many units is 2.5 mg of tirzepatide?
There is no single answer. The number of units depends on the concentration of the vial, in mg per mL, and the syringe used. Use the directions on your pharmacy label, and ask your pharmacist or clinician to confirm the unit count before your first injection.
What is the maximum tirzepatide dose?
The labeled maximum is 15 mg once weekly.[2] Many people do not need to reach it, and your clinician decides what is appropriate for you.
What happens if I miss a dose?
Under the label, a missed dose can be taken within 4 days (96 hours). After that, skip it and resume on your usual day.[1] Do not take two doses close together, and call your clinician or pharmacist if you are unsure what applies to your prescription.
Do higher doses cause more side effects?
Stomach-related side effects were the most common ones in the main weight-management trial, and they appeared most often during dose escalation.[3] Your own experience can differ. Tell your clinician early if side effects are hard to manage.
Talk to a licensed clinician
Dose decisions belong with a licensed clinician who knows your health history. Do not start, stop or change a dose without talking to one. If you are 18 or older and want to find out whether tirzepatide may be appropriate for you, a clinician will review your health assessment and decide. A prescription is not guaranteed.
Important information
- This article is for general education and is not medical advice. Talk to a licensed clinician before starting, stopping or changing any treatment.
- All medications available through ShopMedRx are prescription only and are prescribed only if appropriate after a licensed clinician's review.
- Some medications we offer are compounded. Compounded medications are not FDA-approved, and the FDA does not review compounded drugs for safety, effectiveness or quality before they are marketed.
- Individual results vary. Nothing in this article promises a specific result.
- Prescriptions are written by independent, licensed clinicians through OpenLoop Health and filled by licensed U.S. partner pharmacies.
Sources
- U.S. Food and Drug Administration. Tirzepatide injection for weight reduction and obstructive sleep apnea: prescribing information. U.S. FDA, 2026. https://www.accessdata.fda.gov/drugsatfda_docs/label/2026/217806s042lbl.pdf
- U.S. National Library of Medicine. Tirzepatide injection for weight reduction and obstructive sleep apnea: prescribing information, highlights, dosage and boxed warning. DailyMed. https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=487cd7e7-434c-4925-99fa-aa80b1cc776b
- Jastreboff AM, et al. Tirzepatide once weekly for the treatment of obesity. New England Journal of Medicine, 2022. https://www.nejm.org/doi/full/10.1056/NEJMoa2206038
- U.S. Food and Drug Administration. FDA's concerns with unapproved GLP-1 drugs used for weight loss. U.S. FDA. https://www.fda.gov/drugs/drug-alerts-and-statements/fdas-concerns-unapproved-glp-1-drugs-used-weight-loss
- U.S. National Library of Medicine. Tirzepatide injection for type 2 diabetes: prescribing information, boxed warning and drug interactions. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=d2d7da5d-ad07-4228-955f-cf7e355c8cc0