2.5 mg Retatrutide in Units: Syringe Chart

How many syringe units 2.5 mg of Retatrutide is, for every common vial size and water volume, with the math shown.

Medically reviewed by Juan Pablo Frías, MD · 3 Oct 2026 · DisclosureGLP-1 / GIP / glucagon triple agonistUpdated 3 Oct 2026

Amount: 2.5 mg
At 5 mg/mL: 50 units; e.g. 10 mg vial + 2 mL
At 10 mg/mL: 25 units; e.g. 20 mg vial + 2 mL
Syringe: U-100; 100 units = 1 mL

2.5 mg in units at common mixes

Units on a U-100 syringe (100 units = 1 mL) for a 2.5 mg amount, by vial size and water added. Concentration = vial mg ÷ mL of water; units = dose ÷ concentration × 100.

2.5 mg of Retatrutide in syringe units
Vial	Water	Concentration	Units for 2.5 mg	Volume
5 mg	1 mL	5 mg/mL	50 u	0.50 mL
5 mg	2 mL	2.5 mg/mL	100 u	1.00 mL
5 mg	3 mL	1.667 mg/mL	150 u (over 1 mL)	1.50 mL
10 mg	1 mL	10 mg/mL	25 u	0.25 mL
10 mg	2 mL	5 mg/mL	50 u	0.50 mL
10 mg	3 mL	3.333 mg/mL	75 u	0.75 mL
12 mg	1 mL	12 mg/mL	20.8 u	0.21 mL
12 mg	2 mL	6 mg/mL	41.7 u	0.42 mL
12 mg	3 mL	4 mg/mL	62.5 u	0.63 mL
15 mg	1 mL	15 mg/mL	16.7 u	0.17 mL
15 mg	2 mL	7.5 mg/mL	33.3 u	0.33 mL
15 mg	3 mL	5 mg/mL	50 u	0.50 mL
20 mg	1 mL	20 mg/mL	12.5 u	0.13 mL
20 mg	2 mL	10 mg/mL	25 u	0.25 mL
20 mg	3 mL	6.667 mg/mL	37.5 u	0.38 mL
24 mg	1 mL	24 mg/mL	10.4 u	0.10 mL
24 mg	2 mL	12 mg/mL	20.8 u	0.21 mL
24 mg	3 mL	8 mg/mL	31.3 u	0.31 mL

Calculator and full dosing table

Preset to 2.5 mg in a 10 mg vial. Change any value; the table below the result updates with it.

1Vial size

2Bacteriostatic water added

3Dose per injection

4Syringe (U-100)

Draw to

50units

= 0.5 mL on a 1 mL U-100 insulin syringe

10 mg vial2 mL water2.5 mg dose

Concentration: 5 mg/mL
Doses per vial: 4
Weeks (1 dose/wk): 4

Math only. It does not recommend a dose.

Dosing table for a 10 mg vial

Syringe units (U-100) for each dose, by how much bacteriostatic water you add.

Retatrutide: U-100 syringe units per dose for a 10 mg vial
Dose	1 mL water	2 mL water	2.5 mL water	3 mL water
0.5 mg	5	10	12.5	15
1 mg	10	20	25	30
2 mg	20	40	50	60
2.5 mg	25	50	62.5	75
4 mg	40	80	100	120
6 mg	60	120	150	180
8 mg	80	160	200	240
10 mg	100	200	250	300

How the math works

Concentration is the vial's milligrams divided by the water you add. Volume to draw is your dose divided by that concentration. On a U-100 syringe, 1 mL is 100 units, so units = mL × 100.

10 mg ÷ 2 mL = 5 mg/mL
2.5 mg ÷ 5 mg/mL = 0.5 mL
0.5 mL × 100 = 50 units

50 units · 0.5 mL · 2.5 mg from 10 mg + 2 mL

Math only. The amounts in these tables are reference values for the arithmetic, not dose recommendations.

Common questions

How many units is 2.5 mg of Retatrutide?

It depends on the concentration. With a 10 mg vial and 2 mL of water (5 mg/mL), 2.5 mg is 50 units on a U-100 syringe. The table shows other mixes.

Is 2.5 mg a recommended dose of Retatrutide?

This page is math only. It converts an amount into syringe units and does not recommend a dose. See the dosage page for what studies used.

More on Retatrutide

DosageDoses used in published trials, the titration pattern and a units chart.CalculatorVial, water and dose to syringe units.Side effectsWhat labels and studies report, and what is unknown.ResultsStudy outcomes and when they were measured.PricePrice per mg and per week from dated listings. No vendor links.Legal statusFDA, compounding and WADA status with dates.

Sources

1Triple-Hormone-Receptor Agonist Retatrutide for Obesity: A Phase 2 Trial (Jastreboff AM et al.)New England Journal of Medicine · 2023PMID 37366315Accessed 2 Oct 2026
2Retatrutide, a Triple Hormone Receptor Agonist, for Treatment of Obesity (TRIUMPH-1; Jastreboff AM et al.)New England Journal of Medicine · 2026PMID 42814954Accessed 2 Oct 2026
3A Phase 2 Study of Once-Weekly LY3437943 Compared With Placebo in Participants Who Have Obesity or Are Overweight With Weight-Related Comorbidities (NCT04881760; arms and posted results)ClinicalTrials.gov (U.S. National Library of Medicine) · 2021clinicaltrials.govAccessed 2 Oct 2026
4Metric (SI) Prefixes (NIST Reference on Constants, Units, and Uncertainty)National Institute of Standards and Technology (NIST) · 2025physics.nist.govAccessed 2 Oct 2026
5BASAGLAR (insulin glargine) injection, prescribing information (DailyMed)U.S. Food and Drug Administration / DailyMed (Eli Lilly and Company label) · 2026dailymed.nlm.nih.govAccessed 2 Oct 2026

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