How much BAC water for 10 mg Retatrutide?

Adding 2 mL to a 10 mg Retatrutide vial gives 5 mg/mL; on a U-100 syringe 1 unit = 0.05 mg. 10 mg + 2 mL = 5 mg/mL, so 2 mg is 0.4 mL, or 40 units on a U-100 syringe.

Any volume works; it only sets the concentration. Confusing units with mL has caused FDA-documented dosing errors.

Retatrutide 10 mg: water added vs concentration
Watermg/mLmg per unit2 mg =
1 mL100.120 units
2 mL50.0540 units
3 mL3.330.033360 units

Retatrutide 10 mg reconstitution calculator

Vial mg, water mL and amount give syringe units

mg

Total printed on the vial label.

mL

Diluent volume you add (1 mL = 100 units on a U-100 syringe).

Amount unit

The mass you want in one draw. 1 mg = 1,000 mcg.

Syringe barrel
Show U-40 and U-50 syringes

Result

40units

to draw on a U-100 syringe, 100-unit barrel

Vial: 10 mg with 2 mL diluent 10 mg +2 mL
Syringe filled to 40.0 of 100 units 0 10 20 30 40 50 60 70 80 90 100 U-100, 1 mL
Volume
0.4 mL
Concentration
5 mg/mL
Per unit
50 mcg
Draws per vial
5

10 mg + 2 mL = 5 mg/mL, so 2 mg is 0.4 mL, or 40 units on a U-100 syringe.

Arithmetic only. Not a dosing recommendation. Check every figure against your vial label and lab protocol.

How much water for a 10 mg Retatrutide vial

The water volume is the one number you choose. It doesn't change how much Retatrutide is in the vial. It changes how many units each milligram takes up. The table compares common volumes for 2 mg:

Retatrutide 10 mg: water volume vs reading for 2 mg
Water addedmg/mLmcg per unitUnits for 2 mgSmallest U-100 barrel
0.5 mL 20 200 10 30-unit
1 mL 10 100 20 30-unit
1.5 mL 6.67 66.67 30 30-unit
2 mL 5 50 40 50-unit
2.5 mL 4 40 50 50-unit
3 mL 3.33 33.33 60 100-unit
4 mL 2.5 25 80 100-unit
5 mL 2 20 100 100-unit

Working backwards: to make 2 mg read exactly 10 units, add 0.5 mL; for 20 units, add 1 mL. The BAC water calculator does this for any reading.

Retatrutide 10 mg: mg → units charts

One chart per common water volume. Rows are reference increments, not suggested amounts. Amber values exceed a 100-unit (1 mL) barrel.

10 mg + 1 mL (10 mg/mL)

Retatrutide 10 mg: 10 mg + 1 mL = 10 mg/mL, U-100 syringe
AmountmcgVolume (mL)Syringe units
0.25 mg 250 0.025 2.5
0.5 mg 500 0.05 5
1 mg 1,000 0.1 10
2 mg 2,000 0.2 20
2.5 mg 2,500 0.25 25
3 mg 3,000 0.3 30
4 mg 4,000 0.4 40
5 mg 5,000 0.5 50
6 mg 6,000 0.6 60
7.5 mg 7,500 0.75 75
8 mg 8,000 0.8 80
10 mg 10,000 1 100

10 mg + 2 mL (5 mg/mL)

Retatrutide 10 mg: 10 mg + 2 mL = 5 mg/mL, U-100 syringe
AmountmcgVolume (mL)Syringe units
0.25 mg 250 0.05 5
0.5 mg 500 0.1 10
1 mg 1,000 0.2 20
2 mg 2,000 0.4 40
2.5 mg 2,500 0.5 50
3 mg 3,000 0.6 60
4 mg 4,000 0.8 80
5 mg 5,000 1 100
6 mg 6,000 1.2 120 (> 100)
7.5 mg 7,500 1.5 150 (> 100)
8 mg 8,000 1.6 160 (> 100)
10 mg 10,000 2 200 (> 100)

10 mg + 3 mL (3.33 mg/mL)

Retatrutide 10 mg: 10 mg + 3 mL = 3.33 mg/mL, U-100 syringe
AmountmcgVolume (mL)Syringe units
0.25 mg 250 0.075 7.5
0.5 mg 500 0.15 15
1 mg 1,000 0.3 30
2 mg 2,000 0.6 60
2.5 mg 2,500 0.75 75
3 mg 3,000 0.9 90
4 mg 4,000 1.2 120 (> 100)
5 mg 5,000 1.5 150 (> 100)
6 mg 6,000 1.8 180 (> 100)
7.5 mg 7,500 2.25 225 (> 100)
8 mg 8,000 2.4 240 (> 100)
10 mg 10,000 3 300 (> 100)
Engraving showing a black-and-white card held behind a burette so the curved liquid surface can be read against the scale
Reading a liquid level against a scale, 1895. On a syringe, read the stopper's leading edge. Public domain.

How much one draw can hold

A barrel's capacity caps the largest amount you can measure in one draw. The cap depends on concentration:

Retatrutide 10 mg: maximum mg per full barrel
Water30 units (0.3 mL)50 units (0.5 mL)100 units (1 mL)
1 mL3 mg5 mg10 mg
1.5 mL2 mg3.33 mg6.67 mg
2 mL1.5 mg2.5 mg5 mg
2.5 mL1.2 mg2 mg4 mg
3 mL1 mg1.67 mg3.33 mg

Draws per 10 mg vial

Whole draws of each reference amount the vial contains, regardless of water volume (the water changes the reading, not the total):

Retatrutide 10 mg: whole draws per vial
Amount per drawWhole drawsLeft over
0.25 mg400 mg
0.5 mg200 mg
1 mg100 mg
2 mg50 mg
2.5 mg40 mg
3 mg31 mg
4 mg22 mg
5 mg20 mg
6 mg14 mg
7.5 mg12.5 mg
8 mg12 mg
10 mg10 mg

Real-world yield is usually lower: some liquid stays in the vial and in the syringe's dead space.

Other Retatrutide vial sizes

Or go back to the main Retatrutide calculator, which compares every size side by side.

Frequently asked questions

How much bacteriostatic water do I add to a 10 mg Retatrutide vial?

Any volume works mathematically; the choice sets the concentration. 1 mL gives 10 mg/mL (100 mcg per U-100 unit); 2 mL gives 5 mg/mL (50 mcg per U-100 unit); 3 mL gives 3.33 mg/mL (33.33 mcg per U-100 unit). 2 mL is a common choice because it keeps the arithmetic round.

How many units is 2 mg from a 10 mg Retatrutide vial?

With 1 mL: 20 units. With 2 mL: 40 units. With 3 mL: 60 units. The amount of Retatrutide is the same in every case; only the volume it is dissolved in changes.

How many mg of Retatrutide is 10 units from a 10 mg vial?

10 units on a U-100 syringe is 0.1 mL. With 1 mL of water that is 1 mg; With 2 mL of water that is 0.5 mg; With 3 mL of water that is 0.333 mg.

How much Retatrutide fits in one syringe from a 10 mg vial?

At 5 mg/mL (2 mL of water), a 30-unit barrel holds up to 1.5 mg, a 50-unit barrel 2.5 mg and a 100-unit barrel 5 mg per draw.

Is this a dosing chart?

No. These are arithmetic tables for converting an amount into a syringe reading for a given vial. They do not recommend any amount or schedule.

Storing the Retatrutide vial after mixing

Reconstitution changes how a vial has to be kept: a lyophilized powder and a solution have different temperature, light and time limits, and an opened multi-dose diluent vial has its own clock (CDC guidance: discard 28 days after first puncture unless the manufacturer gives another date). The peptide storage guide covers both states, and the bacteriostatic water guide covers the diluent. Label each vial with the amount, the water added, the concentration and the date.

Sources

  1. What to know about retatrutide — Eli Lilly and Company
  2. FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss — U.S. Food and Drug Administration
  3. FDA alerts health care providers, compounders and patients of dosing errors associated with compounded injectable semaglutide products — U.S. Food and Drug Administration, 2024

Links checked 2026-10-19.