Tirzepatide dosing calculator

Educational reference only

Tirzepatide is a prescription medication in most countries. This page is for educational reference only. Underground Biohacking does not provide dosing protocols, interaction warnings, or usage guidance for prescription compounds. If you are using or considering Tirzepatide, work with a licensed clinician.

CompoundTirzepatide

Vial

Water

Your dose

1 mg = 1000 mcg.

Your syringe

Draw this much

Enter a vial size, water volume and dose to see where to pull.

0 units0.3 mL barrel, U-100 scale30 units

For tracking and calculation purposes only. Not medical advice. Based on a standard U-100 insulin syringe.

Label schedule, for reference

This is the FDA-label schedule for the approved product, shown for reference. It is not a dose suggestion.

2.5 mg once weekly for 4 weeks. Then increase in 2.5 mg steps, each after at least 4 weeks on the current amount. Maintenance is 5, 10 or 15 mg. The maximum is 15 mg weekly.

The grid below is derived from the label's increment rule. The label itself prints the rule, not a week-by-week table.

Week	Amount, once weekly
1-4	2.5 mg
5-8	5 mg
9-12	7.5 mg
13-16	10 mg
17-20	12.5 mg
21+	15 mg

Source: Zepbound (tirzepatide) label, DailyMed sections 2.1 and 2.2 Also: Mounjaro (tirzepatide) label, DailyMed sections 2.1 and 2.2.

How the units are worked out

Your vial holds a fixed amount of peptide. The water you add sets the concentration (how much peptide sits in each millilitre). The concentration then decides how much liquid carries your dose.

Three steps, in order:

Concentration (mcg/mL) = peptide in the vial (mcg) divided by water added (mL).
Volume (mL) = your dose (mcg) divided by the concentration (mcg/mL).
Units to draw = volume (mL) multiplied by 100.

That last step is the syringe, not the peptide. A U-100 insulin syringe is marked so 100 units hold 1 mL, so 0.1 mL reads as 10 units.

A worked example

Enter your dose in the calculator above and this line shows the numbers worked through.

Water and units at a glance

Tirzepatide at different mixes. Every row opens the calculator on that mix.

Vial	Water	Concentration
30 mg	1 mL	30,000 mcg/mL
30 mg	2 mL	15,000 mcg/mL
30 mg	3 mL	10,000 mcg/mL
30 mg	5 mL	6,000 mcg/mL
10 mg	1 mL	10,000 mcg/mL
10 mg	2 mL	5,000 mcg/mL
10 mg	3 mL	3,333 mcg/mL
10 mg	5 mL	2,000 mcg/mL

Units appear once you enter a dose.

Pre-filled numbers are the most-used setups reported by users of public calculators (WPA dosing data, Aug 2026). Not a recommendation.

Mixing and storage

Run the water down the inside wall of the vial and let the powder dissolve on its own. Never shake it. Label the vial with the compound, the total mass, the water you added, the concentration and the date. A sealed freeze-dried vial keeps 12 to 24 months in the fridge at 2 to 8°C. Once mixed with preserved water, such as bacteriostatic water, that drops to roughly 28 days refrigerated. Keep it at the back of the fridge, away from light and away from the door's temperature swings.

Other compounds

Questions

Is tirzepatide a research peptide or a real approved medicine?

It is a real approved medicine. The FDA approved it as Mounjaro for type 2 diabetes and as Zepbound for weight management. Zepbound is also approved for moderate to severe obstructive sleep apnoea in adults with obesity. That puts it in a different category from most peptides written about online. It has a reviewed label, published phase 3 trials, and a known safety profile. It is prescription only, so a doctor has to decide it fits you.

What did the obesity trials actually show?

They showed large, sustained weight loss in people, not in mice. Take adults with obesity and type 2 diabetes. Most people on tirzepatide lost at least five percent of their body weight, against about a third on placebo. A separate three year trial ran in people with obesity and prediabetes. Weight stayed down, and far fewer went on to develop type 2 diabetes. These were randomised, placebo controlled trials with thousands of participants.

Can it treat obstructive sleep apnoea?

Yes, and this is now an approved use. Two phase 3 trials enrolled adults with moderate to severe obstructive sleep apnoea and obesity. One trial enrolled people using a breathing machine at night, one enrolled people who were not. In both, tirzepatide cut the number of breathing pauses per hour of sleep, along with body weight, oxygen dips, inflammation and blood pressure. Sleep related symptoms improved too. The benefit is thought to follow from the weight loss.

How does it compare with semaglutide?

They were compared directly in people with type 2 diabetes over forty weeks. Tirzepatide lowered long term blood sugar more than semaglutide, and it produced more weight loss. Gut side effects were similar in both groups, mostly mild to moderate. The likely reason for the difference is design: semaglutide copies one gut hormone, tirzepatide copies two. That said, this was one trial in one population, and the better option for any individual is a clinical judgement.

What are the most common side effects?

Gut trouble, by a wide margin. Nausea, diarrhoea and vomiting were the most reported events across the trials. Most were mild to moderate, and they clustered in the early weeks while the amount given was being stepped up. A small share of people stopped treatment because of them. Gallbladder and bile duct problems showed up more often than on placebo. Pancreatitis was looked for in a pooled analysis and no increase was found.

What should I ask a doctor before starting?

Ask whether your reason for wanting it matches an approved use, and what the realistic result looks like for you. Ask about your thyroid and pancreas history, and about gallbladder symptoms, since biliary problems came up more often in trials. Ask how the early gut side effects will be handled. Ask what other medicines you take might interact. Ask what happens if you stop, and how progress will be checked over time.