Key Takeaways
- Compounded tirzepatide doses are measured in milligrams (mg), but drawn using units on a U-100 insulin syringe, with the conversion depending entirely on your vial's concentration
- The approved label schedule starts at 2.5 mg weekly for 4 weeks, then 5 mg, with further 2.5 mg increases after at least 4 weeks at each dose up to 15 mg (Zepbound label, September 2026), but the unit count for a 2.5 mg dose varies from 12.5 to 50 units depending on whether your pharmacy compounds at 5, 10, 15, or 20 mg/mL
- The FDA says it has received reports of adverse events, some requiring hospitalization, that may be related to dosing errors with compounded injectable GLP-1 products; a classic scenario is continuing the same unit count after a vial's concentration changed
- A complete dosing chart must account for both the prescribed milligram dose AND the specific concentration printed on your vial label, not a universal conversion
The short answer
A compound tirzepatide dosing chart shows the unit count you draw on a U-100 insulin syringe for each milligram dose at your vial's specific concentration. At 10 mg/mL (a common concentration), 2.5 mg equals 25 units. At 5 mg/mL it's 50 units. At 20 mg/mL it's 12.5 units. The chart changes with every concentration.
To get the units for your own vial, use the tirzepatide dosage calculator. Enter the vial size, the water you add and your dose; it returns the draw in units and millilitres and shows which water volume lands your dose on a printed mark.
Table of contents
- Why compounded tirzepatide requires a concentration-specific dosing chart
- The complete dosing chart for all four common concentrations
- How to read your vial label and identify concentration
- Standard titration schedule and when to increase dose
- Converting between concentrations when switching pharmacies
- What most dosing charts get wrong about "units"
- The three-checkpoint method for error-proof dose drawing
- When your chart needs adjustment: renal impairment, age, and drug interactions
- Storage and shelf life by vial size
- Decision tree: which concentration is right for your dose range
- FDA status and safety reports as of September 5, 2026
- What the approved label says about concentration
- Label adverse-event rates by dose
- FAQ
- Sources
Why compounded tirzepatide requires a concentration-specific dosing chart
Brand-name tirzepatide (Mounjaro, Zepbound) comes in single-dose pens with the dose pre-measured. You click to 2.5 mg and inject. No calculation required. Compounded tirzepatide comes as a liquid in a multi-dose vial. You draw the dose yourself using an insulin syringe, and the amount you draw depends on how concentrated the liquid is.
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Start Free Assessment →Concentration is expressed as milligrams per milliliter (mg/mL). A 10 mg/mL vial contains 10 milligrams of tirzepatide in every 1 milliliter of liquid. To get a 2.5 mg dose, you draw 0.25 mL. On a U-100 insulin syringe, 0.25 mL corresponds to the 25-unit marking.
The problem: not all compounding pharmacies use 10 mg/mL. Some use 5 mg/mL to reduce injection volume for patients sensitive to larger subcutaneous deposits. Others use 20 mg/mL to fit higher total doses in smaller vials for shipping efficiency. Each concentration produces a different unit count for the same milligram dose.
This is why a single universal "tirzepatide dosing chart" doesn't exist. The chart is always paired with a concentration. A chart showing "2.5 mg = 25 units" is only correct at 10 mg/mL. At 5 mg/mL, 2.5 mg is 50 units. Use the wrong chart and you've drawn double or half your prescribed dose.
Correction, September 2026: an earlier version of this paragraph cited a 2025 FDA guidance on concentration variability and a 2025 survey of 483 compounding pharmacies (Johnson et al.). Neither exists. The FDA's guidance on compounded copies of approved drugs was finalized in January 2018 and says nothing about concentrations, and the survey could not be found in PubMed. What the FDA does say, on a page current as of September 1, 2026, is that it "received multiple reports of adverse events, some requiring hospitalization, that may be related to dosing errors associated with compounded injectable semaglutide products." As of May 31, 2026 the agency counted 990 adverse-event reports for compounded semaglutide and more than 730 for compounded tirzepatide. Even the approved product ships at six different multi-dose concentrations, from 4.17 to 25 mg/mL (Zepbound label, September 2026), which is why no fixed unit count can ever be attached to a milligram dose.
The complete dosing chart for all four common concentrations
The table below covers the standard titration doses (2.5 mg through 15 mg) at the four concentrations you're most likely to encounter from a U.S. compounding pharmacy.
| Dose (mg) | 5 mg/mL | 10 mg/mL | 15 mg/mL | 20 mg/mL |
|---|---|---|---|---|
| 2.5 mg | 50 units (0.50 mL) | 25 units (0.25 mL) | 17 units (0.17 mL) | 12.5 units (0.125 mL) |
| 5 mg | 100 units (1.00 mL) | 50 units (0.50 mL) | 33 units (0.33 mL) | 25 units (0.25 mL) |
| 7.5 mg | 150 units (1.50 mL) | 75 units (0.75 mL) | 50 units (0.50 mL) | 37.5 units (0.375 mL) |
| 10 mg | 200 units (2.00 mL) | 100 units (1.00 mL) | 67 units (0.67 mL) | 50 units (0.50 mL) |
| 12.5 mg | 250 units (2.50 mL) | 125 units (1.25 mL) | 83 units (0.83 mL) | 62.5 units (0.625 mL) |
| 15 mg | 300 units (3.00 mL) | 150 units (1.50 mL) | 100 units (1.00 mL) | 75 units (0.75 mL) |
A few patterns worth noting:
10 mg/mL produces the cleanest math. Every dose is a whole number of units divisible by 5. Some pharmacies dispense at 10 mg/mL (a Victor, New York compounding pharmacy's October 2024 patient sheet, for example), while one widely used dose calculator lists 17 and 20 mg/mL as typical (Rivas Weight Loss, March 2026). There is no published market share for any concentration.
5 mg/mL doubles the volume. The 2.5 mg starting dose requires 50 units (0.5 mL), which is the maximum capacity of most 0.5 mL insulin syringes. Doses above 5 mg require a 1 mL syringe. Some patients prefer the larger volume because it's easier to read on the barrel. Others find the larger subcutaneous bolus uncomfortable.
15 mg/mL creates fractional unit counts. A 2.5 mg dose is 17 units (technically 16.67, rounded). A 5 mg dose is 33 units (33.33, rounded). Most U-100 syringes don't have half-unit markings on a 1 mL barrel, so you're estimating between lines. This concentration is rare outside of space-constrained shipping situations.
20 mg/mL is the practical upper limit. Higher concentrations create doses below 10 units, where the syringe markings become difficult to read accurately. Correction, September 2026: an earlier version cited a 2024 human factors study (Martinez et al.) with an error rate above 8 percent; it could not be found in PubMed and has been removed. The practical caution stands: small volumes are harder to read.
If your dose isn't on this chart (e.g., 6 mg, 8 mg), use the formula: (dose in mg ÷ concentration in mg/mL) × 100 = units. Example: 6 mg at 15 mg/mL is (6 ÷ 15) × 100 = 40 units.
How to read your vial label and identify concentration
The concentration is always printed on the vial label, but the format varies by pharmacy. Here's what to look for:
Format 1: Direct mg/mL notation "Tirzepatide Injection 10 mg/mL" This is the simplest. The concentration is 10 mg per mL.
Format 2: Total mg / total mL "Tirzepatide 50 mg / 5 mL Multi-Dose Vial" Divide the first number by the second: 50 ÷ 5 = 10 mg/mL.
Format 3: Total mg only (less common) "Tirzepatide for Injection, 30 mg" The concentration isn't on the vial. Check the pharmacy's dispensing instructions, the patient information sheet in the box, or the prescription label on the outer packaging. If you can't find it anywhere, call the pharmacy before drawing a dose.
Format 4: Reconstitution required "Tirzepatide Lyophilized Powder, 30 mg. Reconstitute with 3 mL Bacteriostatic Water." This is a powder. The concentration is set when you mix it. In this example, 30 mg ÷ 3 mL = 10 mg/mL after reconstitution. The instructions tell you how much water to add. (See our reconstitution guide for the full process.)
Some pharmacies print the concentration in two places: once on the vial and again on a separate label adhered to the box. If the two don't match, call the pharmacy. Labeling errors are rare but not zero.
Correction, September 2026: an earlier version cited a 2025 audit of 1,200 vials (Thompson et al.) reporting a 0.4 percent mislabeling rate. That audit could not be found in PubMed and has been removed. Treat any mismatch between the vial and the box as a reason to call the pharmacy before drawing a dose.
Standard titration schedule and when to increase dose
The schedule below follows the approved label (Zepbound prescribing information, section 2.1, September 2026): 2.5 mg once weekly for 4 weeks as an initiation dose, then 5 mg, then increases in 2.5 mg increments after at least 4 weeks on the current dose, to a maximum of 15 mg. The SURMOUNT-1 trial reached its fixed 5, 10 and 15 mg arms by the same kind of escalation:
| Week | Dose |
|---|---|
| 1-4 | 2.5 mg once weekly |
| 5-8 | 5 mg once weekly |
| 9-12 | 7.5 mg once weekly |
| 13-16 | 10 mg once weekly |
| 17-20 | 12.5 mg once weekly |
| 21+ | 15 mg once weekly (maximum) |
Each dose is held for 4 weeks before increasing. The 4-week interval allows steady-state plasma concentration to be reached (tirzepatide has a half-life of approximately 5 days, per label section 12.3) and gives the body time to adapt to GLP-1 and GIP receptor activation.
When to stay at a dose longer than 4 weeks:
- You are still losing weight steadily at the current dose (a clinician heuristic, not a label rule)
- You experienced moderate to severe nausea, vomiting, or diarrhea in the first 2 weeks of the current dose
- Your provider recommends a slower titration due to age, renal function, or other medications
When to increase on schedule:
- You and your prescriber judge that weight loss has plateaued (the label sets no threshold)
- You tolerated the current dose with minimal side effects
- Your fasting glucose (if diabetic) or HbA1c has plateaued above target
When NOT to increase:
- You're experiencing persistent nausea, vomiting more than twice per week, or signs of dehydration
- You've had an episode of pancreatitis (current or past)
- You're planning surgery or a medical procedure in the next 4 weeks (GLP-1 agonists delay gastric emptying, which affects anesthesia risk)
The approved maximum is 15 mg weekly. Some providers prescribe higher doses off-label (17.5 mg, 20 mg), but the pivotal trials did not study doses above 15 mg. SURMOUNT-1 used fixed-dose arms: at 72 weeks, mean weight change was -15.0 percent at 5 mg, -19.5 percent at 10 mg and -20.9 percent at 15 mg versus -3.1 percent on placebo (Zepbound label, Study 1). The step from 10 to 15 mg added less than the step from 5 to 10 mg. Correction, September 2026: an earlier version described a within-patient comparison of 10 and 15 mg that the trial design did not include.
Converting between concentrations when switching pharmacies
Switching compounding pharmacies mid-treatment is common. Pharmacy A runs out of stock. Pharmacy B offers a lower price. Your insurance changes preferred vendors. Each switch carries a risk: the new pharmacy may compound at a different concentration.
The conversion process:
- Identify your current dose in milligrams. Not units. If you're drawing 50 units at 10 mg/mL, your dose is 5 mg.
- Find the new vial's concentration. Read the label on the new vial.
- Calculate the new unit count. Use the formula: (dose in mg ÷ new concentration) × 100.
Example: You've been taking 7.5 mg weekly, drawn as 75 units from a 10 mg/mL vial. The new pharmacy sends a 15 mg/mL vial. The new unit count is (7.5 ÷ 15) × 100 = 50 units.
The error pattern to watch for: patients continue drawing the same unit count (75 units in this example) from the new vial. At 15 mg/mL, 75 units delivers 11.25 mg, a 50% overdose.
Correction, September 2026: an earlier version cited a 2025 MedWatch analysis (Chen et al.) attributing 23 percent of overdose cases to pharmacy switches. That analysis could not be found in PubMed and has been removed. The FDA's page on compounded GLP-1 drugs (current as of September 1, 2026) confirms only that it has received reports of adverse events that may be related to dosing errors, without ranking the causes.
Best practice: when you receive a new vial, even from the same pharmacy, read the concentration label before drawing. Write the new unit count in permanent marker on the vial box. Don't rely on memory.
What most dosing charts get wrong about "units"
Most published dosing charts for compounded tirzepatide make the same conceptual error: they treat "units" as a property of tirzepatide itself, when units are actually a property of the syringe.
A "unit" in the context of insulin syringes is one one-hundredth of a milliliter (0.01 mL). The term comes from insulin dosing, where 1 unit of U-100 insulin equals 0.01 mL of U-100 insulin solution. Tirzepatide has no unit-based potency. It's measured in milligrams. When we say "25 units of tirzepatide," we mean "25 markings on a U-100 syringe," which corresponds to 0.25 mL of liquid, which contains however many milligrams of tirzepatide are dissolved in that volume.
The error shows up in charts that list "2.5 mg = 25 units" without specifying a concentration. This is only true at 10 mg/mL. At other concentrations it's false.
A second error: charts that show doses in "mL" but expect patients to draw using "units." Patients see "0.25 mL" on the chart, look at the syringe, see "25" printed next to a line, and assume that's the right marking. On a U-100 syringe it is. On a U-500 syringe (used for high-dose insulin), the "25" marking represents 0.05 mL, and the patient has drawn one-fifth of the intended dose.
The fix: every dosing chart must specify three things: the dose in milligrams, the concentration in mg/mL, and the resulting unit count on a U-100 syringe. Omit any one and the chart is incomplete.
The three-checkpoint method for error-proof dose drawing
This is a three-step checklist for dose verification. It adds a few seconds to your injection routine. We do not have data on how many errors it prevents, and an earlier version's 90 percent figure has been removed.
Checkpoint 1: Vial concentration (before you touch the syringe) Read the vial label. Confirm the concentration in mg/mL. Compare it to the concentration written on your dosing instructions. If they don't match, stop and call your provider or pharmacy.
Checkpoint 2: Calculated unit count (before you draw) Use the formula or chart to confirm the unit count for your dose at this concentration. Write it down. Don't rely on memory, especially if you've switched vials recently.
Checkpoint 3: Drawn volume (after you draw, before you inject) Hold the syringe at eye level. Confirm the plunger's leading edge (the part closest to the needle) sits exactly on the calculated unit marking. If you see air bubbles, push the liquid back into the vial and re-draw. A 2 to 3 unit air bubble in a 25-unit dose is an 8 to 12% error.
[Diagram suggestion: three-panel illustration showing (1) a hand holding a vial with the concentration label circled, (2) a notepad with the formula written out, (3) a syringe held at eye level with the plunger aligned to the 25-unit mark and a green checkmark]
The second checkpoint is the one most patients skip. They drew 50 units last week, so they draw 50 units this week. If the vial changed from 10 mg/mL to 5 mg/mL, they've just halved their dose without realizing it.
When your chart needs adjustment: renal impairment, age, and drug interactions
The standard dosing chart assumes normal renal function, age under 65, and no interacting medications. Three situations require modification:
Renal impairment The Zepbound label (section 8.6) recommends no dosage adjustment for renal impairment, including end-stage renal disease; tirzepatide pharmacokinetics were unchanged across degrees of renal impairment. The label does ask prescribers to monitor renal function in patients with vomiting or diarrhea that could lead to volume depletion. Correction, September 2026: an earlier version said SURPASS-4 used 6-week titration intervals for renal patients; that trial escalated every 4 weeks, and the claim has been removed.
Age over 65 The label (section 8.5) reports no overall differences in safety or effectiveness between patients 65 and older and younger adults. Correction, September 2026: an earlier version cited a 2023 post-hoc analysis (Rubino et al.) recommending 6-week intervals for older adults; it could not be found in PubMed and has been removed.
Drug interactions: oral medications Tirzepatide delays gastric emptying; the label says the delay is largest after the first dose and diminishes over time (section 12.2). Section 7.2 asks prescribers to monitor patients on oral medications that depend on threshold concentrations or have a narrow therapeutic index, such as warfarin. The one specific instruction is for oral hormonal contraceptives: switch to a non-oral method or add a barrier method for 4 weeks after starting and for 4 weeks after each dose escalation. Correction, September 2026: an earlier version gave a 6-to-8-hour emptying delay and a 1-hour-before or 8-hours-after timing rule; neither appears in the label, and both have been removed.
Storage and shelf life by vial size
Compounded tirzepatide is shipped refrigerated and stored at 36 to 46°F (2 to 8°C), the same range the Zepbound label specifies (section 16.2). Don't freeze; the label says not to use the product if it has been frozen.
Unopened vials: use the beyond-use date printed on the pharmacy label. Compounded products do not carry a standard shelf life, and an earlier version of this page's 90-to-180-day range had no source.
After first puncture: compounding pharmacies commonly label multi-dose vials "discard 28 days after first use" when refrigerated, following the USP <797> multiple-dose container convention. Some use 21 days. Follow the date on your vial.
Room temperature: for the approved product, the label allows a single-dose pen or vial up to 21 days total at room temperature up to 86°F (30°C), and a multi-dose vial or KwikPen 30 days (section 16.2). No equivalent data exist for compounded vials, so follow the pharmacy's instructions. Correction, September 2026: an earlier version cited a 2024 stability study (Kumar et al.) with 8 and 15 percent potency losses; it could not be found in PubMed and has been removed.
Travel: use an insulated medication travel case with a reusable gel ice pack (not direct ice, which can freeze). TSA allows syringes and vials in carry-on with a prescription label. Don't pack in checked luggage (temperature isn't controlled).
Vial size and dose count: A 2 mL vial at 10 mg/mL contains 20 mg total. At a 2.5 mg weekly dose, that's 8 weeks of therapy. At 5 mg weekly, it's 4 weeks. Most pharmacies dispense 4-week or 8-week supplies. If your vial runs out before the expected number of doses, you've been overdrawing (common if you're not accounting for air bubbles or dead space in the syringe).
Decision tree: which concentration is right for your dose range
Not all concentrations work well for all dose ranges. Here's the decision logic:
If your current or target dose is 2.5 mg:
- Choose 10 mg/mL (25 units) or 5 mg/mL (50 units). Avoid 20 mg/mL (12.5 units is hard to read accurately on most syringes).
If your current or target dose is 5 to 7.5 mg:
- Choose 10 mg/mL (50 to 75 units). This is the sweet spot. All doses are readable whole numbers.
If your current or target dose is 10 to 15 mg:
- Choose 10 mg/mL (100 to 150 units) if you're comfortable with a 1 mL syringe, or 20 mg/mL (50 to 75 units) if you prefer smaller injection volumes.
If you're titrating from 2.5 mg to 15 mg over 6 months:
- Start with 10 mg/mL. It works across the entire range. You'll need to switch to a 1 mL syringe when you reach 10 mg (100 units exceeds the capacity of a 0.5 mL syringe), but the concentration stays the same, so the math doesn't change.
If you have vision impairment or hand tremor:
- Choose 5 mg/mL. The larger unit counts (50, 100, 150) are easier to see and align. The tradeoff is larger injection volume, which some patients find uncomfortable.
If you're traveling frequently:
- Choose 20 mg/mL. Smaller vials (a 30 mg supply fits in 1.5 mL instead of 3 mL) are easier to pack and less likely to break.
Most patients never need to think about this. The pharmacy picks a concentration and ships it. But if you're having trouble reading the syringe, or if injections are painful due to volume, ask your pharmacy if a different concentration is available.
FDA status and safety reports as of September 5, 2026
Compounded tirzepatide sits in a narrower legal space than it did in 2024. The FDA declared the tirzepatide shortage resolved on December 19, 2024 (semaglutide followed on February 21, 2025), and the Fifth Circuit upheld that decision on August 27, 2026. Outside a shortage, compounders may prepare a copy of an approved drug only for a documented clinical need in an individual patient. The FDA's page on unapproved GLP-1 drugs (content current as of September 1, 2026) reports 990 adverse-event reports for compounded semaglutide and more than 730 for compounded tirzepatide as of May 31, 2026, notes that some may relate to dosing errors, and states that the agency has warned firms selling semaglutide, tirzepatide, retatrutide, survodutide or mazdutide labeled "for research purposes." A March 31, 2026 warning letter named tirzepatide powder sold with bacteriostatic water. Practical consequences for anyone using a dosing chart: only a vial dispensed by a licensed pharmacy under a prescription has a reliable concentration on its label, and current compounded pricing is tracked in the Compounded GLP-1 Price Index.
What the approved label says about concentration
The clearest proof that units can never be a fixed number for a milligram dose comes from the approved product itself. The Zepbound label (section 3, September 2026) lists single-dose pens and vials containing 2.5 to 15 mg in 0.5 mL, and a multi-dose vial and KwikPen that each hold 2.4 mL for four weekly doses at six different concentrations:
| Multi-dose strength | Concentration | One weekly dose (0.6 mL) on a U-100 syringe |
|---|---|---|
| 10 mg per 2.4 mL | 4.17 mg/mL | 2.5 mg = 60 units |
| 20 mg per 2.4 mL | 8.33 mg/mL | 5 mg = 60 units |
| 30 mg per 2.4 mL | 12.5 mg/mL | 7.5 mg = 60 units |
| 40 mg per 2.4 mL | 16.7 mg/mL | 10 mg = 60 units |
| 50 mg per 2.4 mL | 20.8 mg/mL | 12.5 mg = 60 units |
| 60 mg per 2.4 mL | 25 mg/mL | 15 mg = 60 units |
Lilly solved the unit problem by making every dose the same 0.6 mL volume and changing the concentration instead. Compounded vials do the opposite: one concentration, many volumes. That is why this chart has to be read against the mg/mL on your own vial, and why the tirzepatide dosage calculator asks for concentration first.
Label adverse-event rates by dose
When deciding whether to hold a dose rather than escalate, it helps to know how common gastrointestinal effects were at each approved dose. From the Zepbound label (section 6.1, SURMOUNT-1, 72 weeks, September 2026):
| Adverse event | 5 mg | 10 mg | 15 mg | Placebo |
|---|---|---|---|---|
| Nausea | 25% | 29% | 28% | 8% |
| Diarrhea | 19% | 21% | 23% | 8% |
| Constipation | 17% | 14% | 11% | 5% |
| Stopped treatment for adverse events | 4.8% | 6.3% | 6.7% | 3.4% |
These are brand-product figures; no equivalent trial data exist for compounded tirzepatide.
FAQ
What concentration of compounded tirzepatide is most common?
10 mg/mL is common because the math is simple: 1 mg of tirzepatide equals 10 units on a U-100 syringe. It is not universal; one dose calculator lists 17 and 20 mg/mL as typical (Rivas Weight Loss, March 2026), and no published survey measures market share. Correction, September 2026: the percentages and the Johnson 2025 citation an earlier answer gave could not be verified and have been removed.
Can I use the same dosing chart if I switch from brand-name to compounded tirzepatide?
No. Brand-name pens deliver the dose automatically. Compounded vials require you to draw the dose, and the unit count depends on concentration. A 5 mg pen click equals 50 units at 10 mg/mL or 25 units at 20 mg/mL. You need a concentration-specific chart.
How do I convert my dose if my pharmacy changes concentration mid-refill?
Find your dose in milligrams (not units). Use the formula (dose ÷ new concentration) × 100 to calculate the new unit count. Example: 7.5 mg at a new 20 mg/mL concentration is (7.5 ÷ 20) × 100 = 37.5 units. Write the new number on the vial box in marker.
Why does my dosing chart show fractional units like 12.5 or 37.5?
These occur at concentrations where the math doesn't divide evenly. Most U-100 syringes have 1-unit markings on a 1 mL barrel, so you estimate halfway between the 12 and 13 lines for 12.5 units. Some 0.3 mL syringes have 0.5-unit markings, which makes fractional doses easier to read.
Is it safe to round a fractional dose up or down?
Rounding by 0.5 to 1 unit is common practice. A 1-unit error on a 25-unit dose is 4%; whether that matters is your prescriber's call, not a fixed rule. Don't round by more than 1 unit without confirming with your provider. Always round the same direction (up or down) for consistency.
What if I accidentally draw the wrong dose?
If you realize before injecting, push the liquid back into the vial and re-draw. If you've already injected, monitor for side effects. For any overdose, contact your prescriber or the Poison Help Line (1-800-222-1222); the Zepbound label advises supportive treatment and a period of observation because the half-life is about 5 days. Underdoses are less concerning; tell your prescriber and do not double the next dose.
Can I split my weekly dose into two smaller injections?
Tirzepatide's half-life is 5 days, so it's designed for once-weekly dosing. Splitting into twice-weekly injections isn't studied and may reduce efficacy (you never reach peak concentration). Some providers allow split dosing during titration if nausea is severe, but this should be a clinical decision, not self-managed.
Do I need a new dosing chart if I'm using tirzepatide for diabetes instead of weight loss?
No. The dosing chart is the same. The approved dose range for type 2 diabetes is 2.5 mg to 15 mg weekly, identical to the weight-loss range. The only difference is the goal: A1c reduction versus weight reduction.
How long does a 5 mL vial last at different doses?
At 10 mg/mL, a 5 mL vial contains 50 mg total. At 2.5 mg weekly, that's 20 weeks. At 5 mg weekly, 10 weeks. At 10 mg weekly, 5 weeks. Most pharmacies don't dispense 5 mL vials for doses above 7.5 mg because the vial expires (28 days after first puncture) before you finish it.
What's the maximum dose of compounded tirzepatide?
The FDA-studied maximum is 15 mg weekly. Some providers prescribe higher doses off-label, but there's no published safety or efficacy data above 15 mg. The SURMOUNT trials didn't test doses above 15 mg.
Can I use a tuberculin syringe instead of an insulin syringe?
Tuberculin syringes are marked in milliliters, not units. You can use one if you convert your dose to mL first (dose in mg ÷ concentration in mg/mL). Example: 5 mg at 10 mg/mL is 0.5 mL. The risk is that tuberculin syringes have larger dead space, so you waste more medication per draw.
Why do some dosing charts show doses above 15 mg?
A few compounding pharmacies offer doses up to 20 mg for patients who plateaued at 15 mg. This is off-label and not supported by clinical trial data. The approved maximum is 15 mg weekly; higher doses were not studied in the pivotal trials, so there are no safety or efficacy data for them.
Does the approved tirzepatide label require exactly 4 weeks at each dose?
No. The Zepbound label (section 2.1, September 2026) says to start at 2.5 mg once weekly for 4 weeks, move to 5 mg, and then increase in 2.5 mg increments only after at least 4 weeks on the current dose, up to 15 mg. Longer intervals are allowed at the prescriber's discretion; the 2.5 mg dose is for initiation only, not maintenance.
How many adverse-event reports has the FDA received for compounded tirzepatide?
As of May 31, 2026, the FDA reported more than 730 adverse-event reports for compounded tirzepatide and 990 for compounded semaglutide, and it says some reports may be related to dosing errors with compounded injectable products (FDA, content current as of September 1, 2026). The counts are voluntary reports, not rates, and they do not distinguish pharmacy-dispensed vials from unlicensed online products.
Do I need a different chart if my vial is 17 mg/mL?
Yes. Apply the formula: dose in mg divided by concentration in mg/mL, times 100. At 17 mg/mL, 2.5 mg is 14.7 units (0.147 mL), 5 mg is 29.4 units, 7.5 mg is 44.1 units and 10 mg is 58.8 units. Round only as your prescriber allows, and re-run the numbers every time a new vial arrives, even from the same pharmacy.
Related guides
- Compound Tirzepatide Dosage Chart: Every Concentration, Every Dose, Every Unit Conversion
- Tirzepatide Compound Doses: The Complete Guide to Every Concentration, Conversion, and Titration Schedule
- The Complete Tirzepatide Compound Dosage Chart: Every Concentration, Every Dose
- How Many Units Is 7.5 mg of Tirzepatide? Complete Conversion Chart for Every Compounded Concentration
- How Many mg Is 30 Units of Tirzepatide? Reverse Conversion Chart for Every Concentration
- Tirzepatide Dosage Chart: Complete mL-to-mg Conversion for Every Concentration
- Tool: dosage calculator
Sources
- Jastreboff AM et al. Tirzepatide Once Weekly for the Treatment of Obesity. New England Journal of Medicine. 2022.
- FDA. Guidance for Industry: Compounded Drug Products That Are Essentially Copies of a Commercially Available Drug Product Under Section 503A of the Federal Food, Drug, and Cosmetic Act. Final guidance, January 2018 (Federal Register, January 19, 2018).
- USP. General Chapter <797> Pharmaceutical Compounding - Sterile Preparations. United States Pharmacopeia. 2024.
- ISO. ISO 8537:2016 Sterile single-use syringes, with or without needle, for insulin. International Organization for Standardization. 2016.
- Frias JP et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2). New England Journal of Medicine. 2021.
- Rosenstock J et al. Efficacy and safety of a novel dual GIP and GLP-1 receptor agonist tirzepatide in patients with type 2 diabetes (SURPASS-1). Diabetes Care. 2021.
- Ludvik B et al. Once-weekly tirzepatide versus once-daily insulin degludec as add-on to metformin with or without SGLT2 inhibitors in patients with type 2 diabetes (SURPASS-3). Lancet. 2021.
- DailyMed (NIH). Zepbound (tirzepatide) prescribing information: sections 2.1, 3, 6.1, 7.2, 8.5, 8.6, 12.2, 12.3, 16.2 and Study 1. Published September 2, 2026. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=487cd7e7-434c-4925-99fa-aa80b1cc776b
- U.S. Food and Drug Administration. FDA's concerns with unapproved GLP-1 drugs used for weight loss (adverse-event counts as of May 31, 2026). Content current as of September 1, 2026. https://www.fda.gov/drugs/drug-alerts-and-statements/fdas-concerns-unapproved-glp-1-drugs-used-weight-loss
- U.S. Food and Drug Administration. Tirzepatide shortage resolution notice (December 19, 2024) and related declaration. https://www.fda.gov/media/185577/download
- U.S. Food and Drug Administration. Warning letter to Gram Peptides regarding tirzepatide, retatrutide and bacteriostatic water marketed for research use. March 31, 2026. https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/gram-peptides-721806-03312026
- The Medicine Shoppe, Victor, New York. Injectable tirzepatide patient information and dosing chart (10 mg/mL). October 2024. https://compoundingrochester.com/wp-content/uploads/2024/10/Injectable_Tirzepatide_incl_chart_Victor.pdf
- Rivas Weight Loss. GLP-1 dose calculator (typical tirzepatide concentrations 17 and 20 mg/mL). Updated March 2026. https://www.rivasweightloss.com/glp1-dose-calculator/
- FormBlends. Compounded GLP-1 Price Index data feed. As of September 3, 2026. https://formblends.com/feeds/glp1-prices.json
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Platform Disclaimer. FormBlends is a digital health platform that connects patients with licensed providers and U.S.-based pharmacies. We do not manufacture, prescribe, or dispense medication directly. All clinical decisions are made by independent licensed providers.
Compounded Medication Notice. Compounded semaglutide and tirzepatide are not FDA-approved. They are prepared by a state-licensed compounding pharmacy in response to an individual prescription. Compounded medications have not undergone the same review process as FDA-approved drugs and are not interchangeable with brand-name products.
Results Disclaimer. Individual results vary. Weight-loss outcomes depend on diet, exercise, adherence, baseline weight, and individual response to treatment. Statements about average outcomes reference published clinical trial data, which may differ from real-world results.
Trademark Notice. Mounjaro and Zepbound are registered trademarks of Eli Lilly and Company. FormBlends is not affiliated with, endorsed by, or sponsored by Eli Lilly and Company.
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