DripVitals health guide
Compounded Tirzepatide Dosage Calculator
Compounded tirzepatide is dispensed in a vial and drawn with a syringe, so a dose prescribed in milligrams has to be converted into units before you can measure it. This compounded tirzepatide dosage calculator does that conversion using the concentration printed on your own vial.
This tool does not choose your dose. It converts a dose your clinician has already prescribed into a syringe measurement. It is not a reason to start, stop, or change a prescription, and it is not a substitute for your prescriber's instructions.
Printed on your vial label. Not the total mg in the vial.
The dose your clinician prescribed. This tool does not choose a dose for you.
Enter your vial concentration and prescribed dose above.
Units measure volume, not dose. A given number of units means nothing without the concentration it came from — 25 units from a 20 mg/mL vial is 5 mg, while 25 units from a 10 mg/mL vial is 2.5 mg. Units are never transferable between vials. Recheck the label every time you start a new vial, especially after a pharmacy change, and confirm with the dispensing pharmacy or your clinician if anything differs from last time.
Last updated October 13, 2026
How the compounded tirzepatide dosage calculator works
A U-100 insulin syringe is marked in units, where 100 units equals 1 millilitre of liquid. Your prescription is written in milligrams of tirzepatide. The bridge between them is your vial's concentration — how many milligrams are dissolved in each millilitre.
units = (dose in mg ÷ concentration in mg/mL) × 100
A 5 mg dose from a 20 mg/mL vial comes to 25 units. The same 5 mg from a 10 mg/mL vial comes to 50 units — twice the volume for the same amount of medication. Neither number is “the” units for 5 mg, because units describe how much liquid you drew, not how much drug it contained.
Why the concentration on your vial matters most
Compounded preparations are made to fill individual prescriptions rather than manufactured to one national standard, so concentration can differ between pharmacies and sometimes between batches from the same pharmacy.
The practical risk is drawing to a remembered number. Someone who has drawn 25 units weekly for months, then receives a refill at a different concentration, can deliver a substantially wrong dose while doing exactly what they did last week. Errors of this kind are the most common serious dosing mistake with compounded GLP-1 medications.
One habit prevents nearly all of it: read the concentration on the label of every new vial before the first injection from it, and recalculate rather than reusing last week's number. If the label differs from your previous vial and your prescription has not changed, ask the pharmacy before injecting.
Tirzepatide dose reference
For context, these are the six FDA-approved tirzepatide doses and the schedule compounded prescriptions are generally built around. Your own prescription may differ — follow it rather than this table.
| Timing | Weekly dose | Stage |
|---|---|---|
| Weeks 1–4 | 2.5 mg | Starting dose |
| Weeks 5–8 | 5 mg | First maintenance dose |
| Weeks 9–12 | 7.5 mg | Escalation |
| Weeks 13–16 | 10 mg | Maintenance dose |
| Weeks 17–20 | 12.5 mg | Escalation |
| Week 21 onward | 15 mg | Maximum dose |
For the full schedule with notes on each step, see the tirzepatide compound dosage chart.
Compounded tirzepatide dosage calculator: FAQs
How does the compounded tirzepatide dosage calculator work?
It converts a dose in milligrams into units on a U-100 insulin syringe using the concentration of your vial. The arithmetic is: dose in mg divided by concentration in mg/mL, multiplied by 100. For example, a 5 mg dose from a 20 mg/mL vial is 25 units. The same 5 mg dose from a 10 mg/mL vial is 50 units.
How many units is 5 mg of compounded tirzepatide?
It depends entirely on your vial's concentration. From a 20 mg/mL vial, 5 mg is 25 units. From a 17 mg/mL vial it is about 29 units. From a 10 mg/mL vial it is 50 units. There is no universal answer, which is exactly why the concentration on your specific label matters.
What concentrations does compounded tirzepatide come in?
Concentrations vary by pharmacy and sometimes between batches. Values around 10, 17, and 20 mg/mL are commonly reported, but yours may differ. Because compounded preparations are made per prescription rather than manufactured to a single standard, the label on your vial is the only reliable source.
Can I use this calculator for a pre-filled pen?
No. Pre-filled pens deliver a fixed dose and require no conversion. This calculator applies only to compounded tirzepatide dispensed in a vial and drawn with a syringe.
Does this calculator tell me what dose to take?
No, and it is not designed to. It converts a dose your clinician has already prescribed into a syringe measurement. Choosing a dose, deciding when to increase it, and deciding whether tirzepatide is appropriate at all are clinical decisions that require evaluation.
What if my result is more than 100 units?
A standard 1 mL U-100 syringe holds 100 units, so a result above that usually means the concentration entered does not match the dose. Do not split a dose across multiple syringes to make it fit. Stop and confirm the concentration on your vial with the dispensing pharmacy.
Why do units change when I get a new vial?
Because units measure volume, not medication. If a refill is prepared at a different concentration, the same prescribed dose in milligrams corresponds to a different number of units. Drawing to your usual number after a concentration change delivers the wrong dose. Recheck the label with every new vial.
Still have questions?
Not sure about your vial or your dose?
If the concentration on your label is unclear, or your prescription and your vial don't seem to match, ask before you inject. A licensed clinician can confirm both.
Talk to a clinicianNot everyone qualifies. Treatment is prescribed only when a licensed clinician determines it is appropriate.
Medically reviewedMedically Reviewed
Dr. Emmanuel Noel Cruz Tancinco, MD
Attending Physician · ABAARM · FAAMM · DABOM
Board-certified in obesity medicine and internal medicine, with practice focused on hormone optimization, metabolic medicine, and longevity-focused care — licensed in all 25 states we serve.
- Hormone Optimization
- Obesity & Metabolic Medicine
- Longevity-Focused Care
- Functional Medicine
Education & certifications (10)
- American Board of Anti-Aging and Regenerative Medicine (ABAARM)
- Anti-Aging Metabolic Medicine, American Academy of Anti-Aging Medicine
- American Board of Obesity Medicine (DABOM)
- American Board of Internal Medicine
- The Institute for Functional Medicine
- Bioidentical Hormone Replacement Therapy certified
- Peptide Certification / Member, International Peptide Society
- Integrative Gastroenterology, Endocrinology, Cardiology & Neurology Certification, The George Washington University School of Medicine and Health Sciences
- Member, The American Academy of Anti-Aging Medicine (A4M)
- Member, American College of Physicians
This page was reviewed for medical accuracy. Treatment decisions are made by a licensed provider after reviewing each patient’s medical history.
Last medically reviewed: October 13, 2026
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