How do I calculate peptide concentration after adding water?

Divide the amount in the vial by the volume of water you added. A 10 mg vial mixed with 2 mL gives 10 ÷ 2 = 5 mg/mL, which is the same as 5,000 mcg/mL.

How many units are in 1 mL on a U-100 syringe?

A U-100 insulin syringe is marked so that 100 units equal 1 mL. Each unit is 0.01 mL, so 0.25 mL reads as 25 units.

How do I convert mg to mcg?

Multiply milligrams by 1,000. 1 mg = 1,000 mcg, so 0.25 mg = 250 mcg. To go back, divide mcg by 1,000.

Can I convert units on the syringe back to an amount?

Yes. Divide the units by 100 to get mL, then multiply by the concentration. 20 units = 0.20 mL; at 5 mg/mL that holds 1 mg. The calculator does this when you type units into the units box.

Does adding more water change how much is in the vial?

No. The total in the vial stays the same. More water lowers the concentration, so the same amount takes up more volume and more units on the syringe.

Why is IU treated differently from mg?

IU measures biological activity, not weight, so there is no universal IU-to-mg rule. The calculator uses the IU count printed on your own vial label instead of guessing.

Does PeptideWhiz suggest doses?

No. PeptideWhiz never suggests or recommends an amount. Every number comes from you, and the tool only does the arithmetic. It is not medical advice.

Do I need an account to use the calculator?

No. The calculator is free and works without an account. An account only lets you save results to your stack and tracker.

Peptide Calculator

Vial and water math for Tirzepatide, with a research record of published human trials. Math only, no suggested amounts.

Free · no account needed

Compound (Optional)

Desired Amount Per Dose

units (U-100)

Vial Strength (Total mg of Your Vial)

Reconstitution Solution Added

Titration Schedule (Optional)

Results

Draw to

—units

Enter amount, vial and Reconstitution Solution

ConcentrationConc.

—mg/mL

Your dose

—mg

Doses / vial

—

More than 100 units (over 1 mL). This won't fit in a single U-100 syringe draw. Double-check your numbers or use more water / a smaller amount.

U-100 Syringe · 1 mL

Notes

PeptideWhizpeptidewhiz.app · research use only

Research use only (RUO). Results are math on the values you enter only, not a recommendation or prescription for human use. Not medical advice. Always verify your own measurements. Full disclaimer

About Tirzepatide

Tirzepatide is a single molecule that acts on two incretin hormone receptors: GIP (glucose-dependent insulinotropic polypeptide) and GLP-1. It was built on the GIP peptide sequence with a fatty side chain that extends its half-life, so trials give it once a week.

Research status

Tirzepatide is the active ingredient in FDA-approved prescription medicines (Mounjaro for type 2 diabetes, Zepbound for chronic weight management and obstructive sleep apnea with obesity). Published trials compare it with placebo, insulin and other GLP-1 medicines.

How the math works for any vial (concentration, U-100 units, mg and mcg) is explained step by step on the main peptide reconstitution calculator page. Read the full What is Tirzepatide? guide for mechanism, trials and conditions researched.

What published studies used

Research record, not a recommendation or protocol

These are published human trials of Tirzepatide from the PeptideWhiz study library. The last column quotes each study’s PubMed abstract word for word, so it shows what that study reported giving its participants under medical supervision. It is not advice, and the calculator never fills these numbers in on its own: you can copy one only by tapping its button and confirming.

Study	Year	Journal	As reported in the abstract	PubMed
Tirzepatide monotherapy in Chinese patients with early type 2 diabetes: A randomized, double-blind, placebo-controlled phase 3 trial (SURPASS-CN-MONO).	2026	Med (New York, N.Y.)	“Adults with type 2 diabetes who had not received antihyperglycemic medication in the previous 90 days were randomized 1:1:1:1 to receive once-weekly 5, 10, or 15 mg tirzepatide or placebo.”	PMID 42296968
Short-Term Combined Treatment With Tirzepatide and Metformin for Overweight/Obese Chinese Women With Polycystic Ovary Syndrome: A Prospective, Open-Label, Randomised Controlled Trial.	2026	Diabetes, obesity & metabolism	“Sixty overweight/obese women with PCOS were randomised to the MET group (1000 mg twice daily [BID]) or the COM group (MET: 1000 mg BID, tirzepatide: 5 mg once weekly [QW]) for 16 weeks.”	PMID 42236268
Effect of Tirzepatide on Health-Related Quality of Life in Japanese Patients With Obesity Disease: Patient-Reported Outcomes From the SURMOUNT-J Study.	2026	Diabetes, obesity & metabolism	“Japanese adults with obesity disease without diabetes were randomized 1:1:1 to tirzepatide (10 or 15 mg) or placebo for 72 weeks as an adjunct to lifestyle modifications.”	PMID 42108080
Shifts in waist-to-height ratio categories within tirzepatide groups: a post-hoc analysis of SURMOUNT-1.	2026	Journal of endocrinological investigation	“Adults with BMI ≥ 30 or ≥ 27 kg/m² and at least one obesity-related complication (ORC), excluding diabetes, were randomized to receive once-weekly tirzepatide (5, 10, or 15 mg) or placebo, alongside a reduced-calorie diet and increased physical activity.”	PMID 42082865
Efficacy of tirzepatide versus semaglutide in achieving therapeutic targets in type 2 diabetes: a post hoc analysis of the SURPASS-2 Trial.	2026	Diabetologia	“Participants were randomised to receive tirzepatide (5, 10 or 15 mg) or semaglutide (1 mg).”	PMID 41419618

Disclaimer: this table is an educational research record. It does not recommend, suggest or endorse any amount, schedule or use, and it is not medical advice. Decisions about any medicine belong with a licensed clinician.

Tirzepatide calculator FAQ

What is Tirzepatide?

Tirzepatide is a dual GIP and GLP-1 receptor agonist. Tirzepatide is a single molecule that acts on two incretin hormone receptors: GIP (glucose-dependent insulinotropic polypeptide) and GLP-1.

Is Tirzepatide approved?

Does this page suggest a Tirzepatide dose?

No. The calculator dose field starts empty and PeptideWhiz never suggests, recommends or calculates an amount for anyone. The study table is a research record of what published trials reported, not a recommendation or protocol.

Where do the study numbers on this page come from?

Each row quotes the abstract of a published human trial (5 trials, 2026 to 2026) word for word, as indexed in PubMed, with a link to the PubMed record. Nothing is rounded, combined or converted.

How does the calculator work with a Tirzepatide vial?

Pick Tirzepatide in step 1 if you want it on your result card, then enter the vial amount printed on your own label and the water volume actually added. The tool divides one by the other for concentration and shows the matching U-100 syringe units for an amount you type. Pens and pre-filled syringes are already in liquid form and are not reconstituted.

Sources

Study rows: PubMed records linked in the table (abstracts checked against PubMed on October 31, 2026). Unit math: see the sources on the main calculator.

Reviewed by the PeptideWhiz team on October 31, 2026. For research and education only.