GLP-1 / triple-agonist maths

Last updated: June 2026 · Reviewed June 2026 · Built by the InjectBuddy team

How many units is each retatrutide dose? (1mg–12mg chart)

Q: What concentration should I use for the chart?

Concentration is set by how much bacteriostatic water you add. Common choices for a 10 mg vial are 1 mL (10 mg/mL) or 2 mL (5 mg/mL). Pick one, keep it consistent, and read only that column. A higher concentration keeps high doses inside a single syringe; a lower one spreads small doses across more units for easier measuring.

Each retatrutide dose converts to syringe units using one formula: units = dose (mg) ÷ concentration (mg/mL) × 100. At 10 mg/mL every 1 mg equals 10 units, so a 4 mg dose is 40 units and a 12 mg dose is 120 units. Retatrutide is investigational — no human dose is approved, so this is a measurement reference only, not a dosing recommendation. This guide walks through the full 1–12 mg titration chart, the worked calculations behind each cell, why concentration changes everything, and answers the questions people ask most.

Key takeaways

Units depend entirely on your reconstituted concentration, which you set by how much bacteriostatic water you add.
The trial titration steps were 1, 2, 4, 8 and 12 mg once weekly — there is no 6 mg rung.
At 5 mg/mL the higher doses spill past 100 units (one full U-100 syringe); a more concentrated vial keeps them in one draw.
Retatrutide has no approved human dose — trial titration was medically supervised. This page is arithmetic, not advice.

Check the numbers for your own vial with the retatrutide dose calculator.

Why concentration sets every number

A units chart only works once you fix one value: the concentration of your reconstituted vial in milligrams per milliliter (mg/mL). Concentration is decided entirely by how much bacteriostatic water you add to the freeze-dried powder, so two people holding identical 10 mg vials can read completely different unit numbers for the same milligram dose.

Insulin syringes are graduated in units where 100 units = 1 mL (the U-100 standard described by MedlinePlus). Once concentration is known, the conversion is fixed arithmetic in two steps — find the volume, then convert volume to units:

Volume (mL) = dose (mg) ÷ concentration (mg/mL)
Units = volume (mL) × 100

Because both steps are linear, doubling the dose doubles the units, and halving the concentration doubles the units. For the reconstitution side of this maths — choosing the water volume in the first place — see the related guides below.

The retatrutide titration ladder

The doses below are the steps tested in the published Phase 2 obesity trial (Jastreboff, NEJM 2023), which escalated through 1, 2, 4, 8 and 12 mg once weekly. Participants started low (1 or 2 mg) and stepped up roughly every four weeks; the trial also found a 2 mg start blunted nausea versus a 4 mg start. There is no 6 mg step.

Ladder step	Weekly dose	Typical hold
1	1 mg	~4 weeks
2	2 mg	~4 weeks
3	4 mg	~4 weeks
4	8 mg	~4 weeks
5	12 mg	maintenance ceiling

This is the trial structure, not a personal prescription. Titration in trials is medically supervised, with holds and reductions based on tolerability.

Master chart: units per dose at common concentrations

Each cell is the units drawn on a U-100 insulin syringe for that dose at that concentration. Find your concentration column, then read down the ladder.

Weekly dose	5 mg/mL	10 mg/mL	20 mg/mL
1 mg	20 units	10 units	5 units
2 mg	40 units	20 units	10 units
4 mg	80 units	40 units	20 units
8 mg	160 units*	80 units	40 units
12 mg	240 units*	120 units*	60 units

*Any value above 100 units exceeds a single standard 1 mL U-100 syringe and needs more than one draw, or a higher concentration. That is exactly why higher concentrations are common at the top of the ladder.

Units rise in step with the dose: at 10 mg/mL the 1–12 mg ladder maps to 10–120 units, and the 12 mg step crosses the one-syringe ceiling of 100 units.

How this is calculated

Every cell is the same formula applied once. Here are the worked steps so you can reproduce any number.

Set the concentration

10 mg vial + 1 mL water → 10 mg ÷ 1 mL = 10 mg/mL.

2 mg at 10 mg/mL

2 ÷ 10 = 0.2 mL → 0.2 × 100 = 20 units.

8 mg at 10 mg/mL

8 ÷ 10 = 0.8 mL → 0.8 × 100 = 80 units.

12 mg at 10 mg/mL

12 ÷ 10 = 1.2 mL → 1.2 × 100 = 120 units — over one syringe, so split or concentrate.

4 mg at 5 mg/mL (dilute)

4 ÷ 5 = 0.8 mL → 0.8 × 100 = 80 units. Same drug, twice the units of the 10 mg/mL column.

12 mg at 20 mg/mL (concentrated)

12 ÷ 20 = 0.6 mL → 0.6 × 100 = 60 units, comfortably inside one syringe.

Shortcut at 10 mg/mL

Every 1 mg = 10 units, so units = dose × 10. A 4 mg dose is 40 units with no division needed.

Concentration changes the whole chart

The single biggest source of dosing error is reading units from the wrong concentration. The milligram dose is identical across the table below; only the units move as you change how much water goes into the same 10 mg vial.

Water added to 10 mg vial	Concentration	4 mg dose reads
0.5 mL	20 mg/mL	20 units
1 mL	10 mg/mL	40 units
2 mL	5 mg/mL	80 units

The doubling trap

Vial A (1 mL water, 10 mg/mL) reads 40 units for 4 mg. Vial B (2 mL water, 5 mg/mL) reads 80 units for the same 4 mg. Drawing 80 units from Vial A delivers 8 mg — double the intended dose. Always recalculate when the water volume changes.

Evidence status and supervision

Retatrutide (LY3437943) is an investigational triple agonist of the GLP-1, GIP and glucagon receptors. It currently has no regulatory approval for any use and cannot be lawfully prescribed outside a clinical trial. The human data that exists comes from controlled Phase 2 trials in obesity (Jastreboff), type 2 diabetes (Rosenstock) and steatotic liver disease (Sanyal), all with medical screening, supervised titration and monitoring; later-phase studies are listed on ClinicalTrials.gov.

Using retatrutide outside that setting forgoes the dose adjustments, safety labs and side-effect management that trials provide. This page is a unit-conversion reference, not medical advice and not an endorsement of unsupervised use. The conversions tell you how many units correspond to a stated dose; they say nothing about whether that dose is safe or appropriate for you — that is a question for a licensed clinician.

So, how many units is each retatrutide dose?

The units for any retatrutide dose depend entirely on the concentration of your reconstituted vial: units = dose (mg) divided by concentration (mg/mL), multiplied by 100. At the most common concentration of 10 mg/mL, the trial titration ladder maps neatly — 1 mg is 10 units, 4 mg is 40 units, 8 mg is 80 units, and 12 mg is 120 units (which requires two draws or a more concentrated vial). Change the water volume you add and every number in the chart changes with it. For the exact units at your reconstituted concentration, enter your vial strength and water volume into the retatrutide dose calculator.

FAQs

How many units is each retatrutide dose?

It depends on your reconstituted concentration. At 10 mg/mL: 1 mg is 10 units, 2 mg is 20 units, 4 mg is 40 units, 8 mg is 80 units, and 12 mg is 120 units. The formula is units = dose (mg) divided by concentration (mg/mL), multiplied by 100.

What concentration should I use for the chart?

There is no single correct concentration; it is set by how much bacteriostatic water you add. Common choices for a 10 mg vial are 1 mL (10 mg/mL) or 2 mL (5 mg/mL). Pick one, keep it consistent, and read only that column. A higher concentration keeps high doses inside a single syringe; a lower one spreads small doses across more units for easier measuring.

Why is there no 6 mg step in the chart?

The published Phase 2 obesity trial escalated through 1, 2, 4, 8 and 12 mg weekly — there was no 6 mg rung. This chart follows the same steps, but you can calculate any intermediate dose with units = dose ÷ concentration × 100.

My 12 mg dose comes out over 100 units. Is that wrong?

No. At 5 or 10 mg/mL a 12 mg dose exceeds one full 1 mL U-100 syringe (240 and 120 units). That means two separate draws or a more concentrated vial. Reconstituting a 10 mg vial with 0.5 mL gives 20 mg/mL, where 12 mg is 60 units and fits in one syringe.

Does this chart mean retatrutide is safe to self-administer?

No. Retatrutide is investigational, unapproved, and was studied only under medical supervision with screening and monitoring. This chart converts a stated dose into syringe units; it is not a recommendation to use the drug or a statement that any dose is safe for you. Those decisions belong to a licensed clinician.

How do I check the numbers for my exact vial?

Enter your vial strength, water volume and target dose into the retatrutide calculator. It computes your concentration and the units for each dose on the ladder, so you do not rely on a generic chart that may not match your reconstitution.

Sources

Jastreboff AM, Kaplan LM, Frias JP, et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial. N Engl J Med. 2023;389(6):514-526. pubmed.ncbi.nlm.nih.gov/37366315.
Rosenstock J, Frias J, Jastreboff AM, et al. Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes: a randomised, double-blind, placebo and active-controlled, parallel-group, phase 2 trial. Lancet. 2023;402(10401):529-544. pubmed.ncbi.nlm.nih.gov/37385280.
Sanyal AJ, Bhatt DL, Harrison S, et al. Triple hormone receptor agonist retatrutide for metabolic dysfunction-associated steatotic liver disease: a randomized phase 2a trial. Nat Med. 2024;30(7):2037-2048. pubmed.ncbi.nlm.nih.gov/38858523.
ClinicalTrials.gov. Studies of retatrutide (LY3437943). U.S. National Library of Medicine. clinicaltrials.gov/search?intr=retatrutide.
MedlinePlus Medical Encyclopedia. Giving an insulin injection (U-100, 100 units = 1 mL). U.S. National Library of Medicine. medlineplus.gov/ency/patientinstructions/000660.htm.

This guide is for general educational purposes only and does not constitute medical advice. Retatrutide is investigational and unapproved; no human dose is established. Always follow a licensed clinician's instructions.