20 mg vial

Retatrutide: a 20 mg vial

What a 20 mg vial of Retatrutide becomes once it is mixed, and what each dose reported in the sources draws to on a syringe. Every figure is arithmetic on the vial size in the heading — none of it is a recommendation, and the doses are the ones our sources describe rather than ones we picked.

Leading with

20 mg + 1 mL bacteriostatic water = 20 mg/mL

Chosen because it puts the reported doses on readable marks of a 1 mL U-100 syringe. Other volumes are perfectly valid — the dilution table further down covers them, and the concentration changes what every dose draws to.

What each reported dose draws to

At 20 mg/mL, on a 1 mL U-100 syringe. Every row names the source it came from, and a trial protocol and a community convention are not the same kind of information.

Reported doses for Retatrutide, converted to syringe units for a 20 mg vial.
Goal	Dose	Units	Doses in this vial	Source
Phase 2 starting doseOnce weekly · Subcutaneous	2 mg	10 units	10	Clinical trial
Phase 2 escalation and maintenance armsOnce weekly, escalated in steps · Subcutaneous	4 mg – 12 mg	20 units – 60 units	5	Clinical trial

Check every figure against the vial in front of you before drawing. Vials are filled with an overage and labels are not a guarantee. Change any of these numbers in the calculator.

How long a vial lasts

Vials round up, because most of a vial is not a thing you can buy. Only doses with a stated continuous frequency appear here — anything described as a course, a range or “as needed” has no honest weekly rate, so it is left out.

Phase 2 starting dose

Once weekly

One 20 mg vial holds 10 doses at this dose, which is 10 weeks of use.

Supplies for Phase 2 starting dose, by cycle length.
Cycle	Doses	20 mg vials	Syringes	Bacteriostatic water
8 weeks	8	1	8	1 mL
12 weeks	12	2	12	2 mL
16 weeks	16	2	16	2 mL

Phase 2 escalation and maintenance arms

Once weekly, escalated in steps

One 20 mg vial holds 1–5 doses at this dose, which is 1–5 weeks of use.

Supplies for Phase 2 escalation and maintenance arms, by cycle length.
Cycle	Doses	20 mg vials	Syringes	Bacteriostatic water
8 weeks	8	2–8	8	2 mL – 8 mL
12 weeks	12	3–12	12	3 mL – 12 mL
16 weeks	16	4–16	16	4 mL – 16 mL

Syringes assume one per dose and no wastage. Water assumes each vial is mixed at 1 mL. Neither accounts for a dropped vial, a bent needle or a dose you decide to change, all of which happen.

If you add a different amount of water

The same 20 mg of compound, at four common volumes. More water means a larger, easier-to-measure draw of a weaker solution; less water means the opposite. The amount of compound you inject is identical in every row — only the volume carrying it changes.

Concentration and draw volume for a 20 mg vial at four water volumes.
Water added	Concentration	2 mg draws to
1 mLshown above	20 mg/mL	10 units units · 0.1 mL
2 mL	10 mg/mL	20 units units · 0.2 mL
3 mL	6.667 mg/mL	30 units units · 0.3 mL
5 mL	4 mg/mL	50 units units · 0.5 mL

Storage

Before mixing

Refrigerated at 2–8 °C, protected from light and moisture.

After mixing

Refrigerated at 2–8 °C. Do not freeze.

Other vial sizes

The same compound, different arithmetic.

The full Retatrutide profile →Printable one-pager →

Arithmetic on the vial size named above and the doses our sources report. Nothing here is a recommendation, a protocol or medical advice, and no clinician has reviewed it. Speak to a licensed healthcare provider before acting on any of it.

Sources for the doses above are listed in full on the Retatrutide profile, each with the trial or label it came from.