Peptide Calculators
Last updated: June 2026
Retatrutide Dose-to-Units Chart (1mg to 12mg)
This is a reference chart that converts each dose on the retatrutide titration ladder (1 mg, 2 mg, 4 mg, 8 mg, 12 mg) into insulin-syringe units at common reconstitution concentrations. It is a measurement tool only, not a dosing recommendation, and retatrutide is an investigational drug with no approved human use outside clinical trials.
How to read a retatrutide units chart
A retatrutide units chart only works once you fix one number: the concentration of your reconstituted vial, in milligrams per millilitre (mg/mL). Concentration depends entirely on how much bacteriostatic water you add to the dry powder, so two people holding the same 10 mg vial can have completely different unit readings.
Once concentration is known, the conversion to insulin-syringe "units" is fixed arithmetic. Insulin syringes are graduated in units where 100 units = 1 mL (U-100). The formula is:
- Volume (mL) = dose (mg) ÷ concentration (mg/mL)
- Units = volume (mL) × 100
Combined: units = dose (mg) ÷ concentration (mg/mL) × 100. The charts below apply this to every rung of the 1 mg to 12 mg ladder. For the reconstitution side of this maths, see the peptide reconstitution guide.
The retatrutide titration ladder
The doses in this chart are the steps tested in the published Phase 2 trial of retatrutide for obesity, which used an escalation sequence of 1 → 2 → 4 → 8 → 12 mg once weekly, with each step typically held for four weeks before the next increase. There is no 6 mg step in that schedule.
| 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. Retatrutide is investigational; titration in trials is medically supervised with dose holds and reductions based on tolerability. For why the steps are spaced this way, see the retatrutide titration schedule.
Master chart: units per dose at common concentrations
This is the full retatrutide units chart. Each cell is the volume drawn on a U-100 insulin syringe for that dose at that concentration. Find your concentration column, then read down the titration 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 the capacity of a single standard 1 mL U-100 syringe and would require more than one draw, or a higher concentration. This is exactly why higher concentrations are common at the top of the ladder. Verify every figure for your own vial with the retatrutide calculator.
How each cell is calculated
Every number in the chart is the same formula applied once. Worked examples for one concentration:
Example
Vial: 10 mg retatrutide reconstituted with 1 mL bacteriostatic water → concentration = 10 mg ÷ 1 mL = 10 mg/mL.
2 mg dose: volume = 2 ÷ 10 = 0.2 mL. Units = 0.2 × 100 = 20 units.
8 mg dose: volume = 8 ÷ 10 = 0.8 mL. Units = 0.8 × 100 = 80 units.
12 mg dose: volume = 12 ÷ 10 = 1.2 mL. Units = 1.2 × 100 = 120 units — over one full syringe, so split into two draws or reconstitute more concentrated.
The relationship is linear: at a fixed concentration, doubling the dose doubles the units. At 10 mg/mL, every 1 mg equals exactly 10 units, so the whole column is just the dose times ten.
Concentration changes the whole chart
The single biggest source of dosing error is reading units from the wrong concentration. The dose in milligrams is identical across the chart; only the units move. The table below shows how the same 4 mg dose shifts as you change how much water you add to a 10 mg vial.
| Water added to 10 mg vial | Concentration | 4 mg dose = |
|---|---|---|
| 0.5 mL | 20 mg/mL | 20 units |
| 1 mL | 10 mg/mL | 40 units |
| 2 mL | 5 mg/mL | 80 units |
Example
Two vials, both labelled 10 mg, both dosing 4 mg. Vial A has 1 mL water (10 mg/mL) and reads 40 units. Vial B has 2 mL water (5 mg/mL) and reads 80 units. Both deliver the same 4 mg of drug. Drawing 80 units from Vial A would be double the intended dose. Always recalculate when the water volume changes.
If you prefer thinking in milligrams-per-millilitre directly, the reconstitution guide covers choosing a water volume that keeps your target doses inside one syringe.
Evidence status and supervision
Retatrutide is an investigational triple agonist (GLP-1, GIP and glucagon receptors). As of this writing it is in Phase 3 trials and has no regulatory approval for any use; it is not an approved medicine you can be lawfully prescribed for weight loss or diabetes outside a trial. The human data that exists comes from controlled clinical trials with medical screening, supervised titration and monitoring.
Using retatrutide outside that setting is unsafe and is done without the dose adjustments, safety labs and side-effect management that trials provide. This page is a maths and unit-conversion reference, not medical advice and not an endorsement of unsupervised use. The conversions here 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.
What users report: community discussions describe starting at 1–2 mg and escalating slowly to limit nausea, mirroring the trial schedule. This is anecdotal community experience, not clinical guidance, and is included only for context. There is no solid evidence supporting any unsupervised dosing protocol, and use outside a monitored trial is unsafe.
FAQs
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 concentration spreads small doses across more units for easier measuring.
Why is there no 6 mg step in the chart?
The published Phase 2 retatrutide trial used an escalation sequence of 1, 2, 4, 8 and 12 mg weekly. There was no 6 mg rung in that schedule, so this chart follows the same steps. You can still calculate any intermediate dose with the units = dose / concentration x 100 formula.
My 12 mg dose comes out over 100 units. Is that wrong?
No. At 5 mg/mL or 10 mg/mL, a 12 mg dose exceeds one full 1 mL U-100 syringe (240 and 120 units respectively). That means either 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 have to read 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. PMID: 37366315. 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 conducted in the USA. Lancet. 2023;402(10401):529-544. www.thelancet.com/journals/lancet/article/PIIS0140-6736(23)01053-X/abstract.
- 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.S. National Library of Medicine. medlineplus.gov/ency/patientinstructions/000660.htm.
- 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. PMCID: PMC11271400. pmc.ncbi.nlm.nih.gov/articles/PMC11271400.
This guide is for general educational purposes only and does not constitute medical advice. Always follow your prescriber's specific instructions.