How much water to reconstitute 5 mg semaglutide?

The water volume only sets the concentration; any volume works mathematically. 5 mg in 2 mL gives 2.5 mg/mL (0.25 mg = 10 units); in 1 mL it gives 5 mg/mL (0.25 mg = 5 units). Larger volumes give larger, easier-to-read unit counts. This is arithmetic, not a preparation instruction.

Are FDA-approved pens and vials reconstituted?

No. Zepbound, Mounjaro, Wegovy and Ozempic are supplied as ready-to-use solutions. Reconstitution math applies to lyophilized (freeze-dried) vials, which for these molecules are compounded or research products that the FDA has not approved.

How do I choose the water volume for a target unit mark?

Rearrange the formula: water mL = vial mg × target units ÷ (dose mg × 100). For a 10 mg vial and a 2.5 mg amount that should read 25 units, water = 10 × 25 ÷ 250 = 1 mL.

Does more water change the amount of drug?

No. The vial mg is fixed; water only spreads it over more volume. Doubling the water halves the concentration and doubles the units needed for the same mg.

Is semaglutide FDA approved?

Yes. FDA approved as Ozempic (type 2 diabetes) and Wegovy (weight management, cardiovascular risk reduction). Numbers on this page quote the FDA prescribing information; your prescriber sets your dose.

Semaglutide Reconstitution Calculator & Chart

Short answer

Concentration = vial mg ÷ water mL; units = dose mg ÷ concentration × 100. Example: 5 mg + 2 mL = 2.5 mg/mL, so 0.25 mg = 10 units. For a target mark, water mL = vial mg × target units ÷ (dose mg × 100). Arithmetic as of Oct 19, 2026; not dosing advice.

Units on U-100: 20 U (raw 20)
Volume: 0.2 mL
Concentration: 2.5 mg/mL
Draws per vial: 10
Water for target mark: 5 mL

Lands exactly on a printed mark: 20 U.

1 unit = 0.025 mg · 10 units = 0.25 mg at 2.5 mg/mL.

Drag the plunger, or focus the diagram and use the arrow keys, to set the amount by syringe mark.

Water volumes that put 0.5 mg exactly on a printed mark of this syringe:

U-100 scale: 100 units = 1 mL, so 1 unit = 0.01 mL. Units round to the nearest 0.5 U.

5 mg ÷ 2 mL = 2.5 mg/mL. 0.5 mg ÷ 2.5 mg/mL = 0.2 mL × 100 = 20 U.

Math, parameters and sources: model card.

From vial to syringe: the default example (5 mg vial, 2 mL water, 0.5 mg) in three steps

Vial and water
5 mg + 2 mL
The mg in the vial never changes; water only sets how spread out it is.
Concentration
5 ÷ 2 = 2.5 mg/mL
Milligrams in every milliliter of solution.
Units on a U-100 syringe
0.5 mg ÷ 2.5 = 0.2 mL = 20 U
100 units = 1 mL, so units = mL × 100 (rounded to 0.5 U).

Vial × water chart

Pre-calculated U-100 readings for common vial sizes and water volumes. Every cell uses the same formula as the calculator. Brand Wegovy and Ozempic products are ready-to-use solutions and are not reconstituted; these tables are arithmetic for lyophilized vials.

5 mg vial: U-100 units to draw for each dose (1 mL = 5 mg/mL; 2 mL = 2.5 mg/mL; 3 mL = 1.667 mg/mL)
Dose	1 mL water5 mg/mL	2 mL water2.5 mg/mL	3 mL water1.667 mg/mL
0.25 mg	5 U	10 U	15 U
0.5 mg	10 U	20 U	30 U
1 mg	20 U	40 U	60 U
2 mg	40 U	80 U	—
2.5 mg	50 U	100 U	—
4 mg	80 U	—	—
5 mg	100 U	—	—
6 mg	—	—	—
8 mg	—	—	—
9 mg	—	—	—
10 mg	—	—	—
12 mg	—	—	—

10 mg vial: U-100 units to draw for each dose (1 mL = 10 mg/mL; 2 mL = 5 mg/mL; 3 mL = 3.333 mg/mL)
Dose	1 mL water10 mg/mL	2 mL water5 mg/mL	3 mL water3.333 mg/mL
0.25 mg	2.5 U	5 U	7.5 U
0.5 mg	5 U	10 U	15 U
1 mg	10 U	20 U	30 U
2 mg	20 U	40 U	60 U
2.5 mg	25 U	50 U	75 U
4 mg	40 U	80 U	—
5 mg	50 U	100 U	—
6 mg	60 U	—	—
8 mg	80 U	—	—
9 mg	90 U	—	—
10 mg	100 U	—	—
12 mg	—	—	—

15 mg vial: U-100 units to draw for each dose (1 mL = 15 mg/mL; 2 mL = 7.5 mg/mL; 3 mL = 5 mg/mL)
Dose	1 mL water15 mg/mL	2 mL water7.5 mg/mL	3 mL water5 mg/mL
0.25 mg	1.5 U (raw 1.67)	3.5 U (raw 3.33)	5 U
0.5 mg	3.5 U (raw 3.33)	6.5 U (raw 6.67)	10 U
1 mg	6.5 U (raw 6.67)	13.5 U (raw 13.33)	20 U
2 mg	13.5 U (raw 13.33)	26.5 U (raw 26.67)	40 U
2.5 mg	16.5 U (raw 16.67)	33.5 U (raw 33.33)	50 U
4 mg	26.5 U (raw 26.67)	53.5 U (raw 53.33)	80 U
5 mg	33.5 U (raw 33.33)	66.5 U (raw 66.67)	100 U
6 mg	40 U	80 U	—
8 mg	53.5 U (raw 53.33)	—	—
9 mg	60 U	—	—
10 mg	66.5 U (raw 66.67)	—	—
12 mg	80 U	—	—

20 mg vial: U-100 units to draw for each dose (1 mL = 20 mg/mL; 2 mL = 10 mg/mL; 3 mL = 6.667 mg/mL)
Dose	1 mL water20 mg/mL	2 mL water10 mg/mL	3 mL water6.667 mg/mL
0.25 mg	1.5 U (raw 1.25)	2.5 U	4 U (raw 3.75)
0.5 mg	2.5 U	5 U	7.5 U
1 mg	5 U	10 U	15 U
2 mg	10 U	20 U	30 U
2.5 mg	12.5 U	25 U	37.5 U
4 mg	20 U	40 U	60 U
5 mg	25 U	50 U	75 U
6 mg	30 U	60 U	90 U
8 mg	40 U	80 U	—
9 mg	45 U	90 U	—
10 mg	50 U	100 U	—
12 mg	60 U	—	—

30 mg vial: U-100 units to draw for each dose (1 mL = 30 mg/mL; 2 mL = 15 mg/mL; 3 mL = 10 mg/mL)
Dose	1 mL water30 mg/mL	2 mL water15 mg/mL	3 mL water10 mg/mL
0.25 mg	1 U (raw 0.83)	1.5 U (raw 1.67)	2.5 U
0.5 mg	1.5 U (raw 1.67)	3.5 U (raw 3.33)	5 U
1 mg	3.5 U (raw 3.33)	6.5 U (raw 6.67)	10 U
2 mg	6.5 U (raw 6.67)	13.5 U (raw 13.33)	20 U
2.5 mg	8.5 U (raw 8.33)	16.5 U (raw 16.67)	25 U
4 mg	13.5 U (raw 13.33)	26.5 U (raw 26.67)	40 U
5 mg	16.5 U (raw 16.67)	33.5 U (raw 33.33)	50 U
6 mg	20 U	40 U	60 U
8 mg	26.5 U (raw 26.67)	53.5 U (raw 53.33)	80 U
9 mg	30 U	60 U	90 U
10 mg	33.5 U (raw 33.33)	66.5 U (raw 66.67)	100 U
12 mg	40 U	80 U	—

40 mg vial: U-100 units to draw for each dose (1 mL = 40 mg/mL; 2 mL = 20 mg/mL; 3 mL = 13.333 mg/mL)
Dose	1 mL water40 mg/mL	2 mL water20 mg/mL	3 mL water13.333 mg/mL
0.25 mg	0.5 U (raw 0.63)	1.5 U (raw 1.25)	2 U (raw 1.88)
0.5 mg	1.5 U (raw 1.25)	2.5 U	4 U (raw 3.75)
1 mg	2.5 U	5 U	7.5 U
2 mg	5 U	10 U	15 U
2.5 mg	6.5 U (raw 6.25)	12.5 U	19 U (raw 18.75)
4 mg	10 U	20 U	30 U
5 mg	12.5 U	25 U	37.5 U
6 mg	15 U	30 U	45 U
8 mg	20 U	40 U	60 U
9 mg	22.5 U	45 U	67.5 U
10 mg	25 U	50 U	75 U
12 mg	30 U	60 U	90 U

60 mg vial: U-100 units to draw for each dose (1 mL = 60 mg/mL; 2 mL = 30 mg/mL; 3 mL = 20 mg/mL)
Dose	1 mL water60 mg/mL	2 mL water30 mg/mL	3 mL water20 mg/mL
0.25 mg	0.5 U (raw 0.42)	1 U (raw 0.83)	1.5 U (raw 1.25)
0.5 mg	1 U (raw 0.83)	1.5 U (raw 1.67)	2.5 U
1 mg	1.5 U (raw 1.67)	3.5 U (raw 3.33)	5 U
2 mg	3.5 U (raw 3.33)	6.5 U (raw 6.67)	10 U
2.5 mg	4 U (raw 4.17)	8.5 U (raw 8.33)	12.5 U
4 mg	6.5 U (raw 6.67)	13.5 U (raw 13.33)	20 U
5 mg	8.5 U (raw 8.33)	16.5 U (raw 16.67)	25 U
6 mg	10 U	20 U	30 U
8 mg	13.5 U (raw 13.33)	26.5 U (raw 26.67)	40 U
9 mg	15 U	30 U	45 U
10 mg	16.5 U (raw 16.67)	33.5 U (raw 33.33)	50 U
12 mg	20 U	40 U	60 U

Units = dose mg ÷ (vial mg ÷ water mL) × 100, rounded to the nearest 0.5 U; the raw value is shown in brackets when rounding changed it. A dash means the draw would exceed a 100-unit syringe or the vial. Arithmetic only; not dosing advice.

Rounding, syringe size and dead space

Results round to the nearest 0.5 unit because U-100 syringes are marked in 1-unit (30 and 50 U) or 2-unit (100 U) steps; the raw value is always shown next to the rounded one. The calculator warns when a draw exceeds the chosen syringe or falls under 2 units, where a half-unit reading error is 25% or more of the amount. Dead space (liquid held in the hub and needle) does not change the units for one draw, but it lowers how many draws a vial yields.

Frequently asked questions

How much water to reconstitute 5 mg semaglutide?: The water volume only sets the concentration; any volume works mathematically. 5 mg in 2 mL gives 2.5 mg/mL (0.25 mg = 10 units); in 1 mL it gives 5 mg/mL (0.25 mg = 5 units). Larger volumes give larger, easier-to-read unit counts. This is arithmetic, not a preparation instruction.
Are FDA-approved pens and vials reconstituted?: No. Zepbound, Mounjaro, Wegovy and Ozempic are supplied as ready-to-use solutions. Reconstitution math applies to lyophilized (freeze-dried) vials, which for these molecules are compounded or research products that the FDA has not approved.
How do I choose the water volume for a target unit mark?: Rearrange the formula: water mL = vial mg × target units ÷ (dose mg × 100). For a 10 mg vial and a 2.5 mg amount that should read 25 units, water = 10 × 25 ÷ 250 = 1 mL.
Does more water change the amount of drug?: No. The vial mg is fixed; water only spreads it over more volume. Doubling the water halves the concentration and doubles the units needed for the same mg.
Is semaglutide FDA approved?: Yes. FDA approved as Ozempic (type 2 diabetes) and Wegovy (weight management, cardiovascular risk reduction). Numbers on this page quote the FDA prescribing information; your prescriber sets your dose.

Sources

WEGOVY (semaglutide) injection, for subcutaneous use; WEGOVY (semaglutide) tablets, for oral use - Full Prescribing Information (SPL, Revised 6/2026). Novo Nordisk / National Library of Medicine DailyMed, Jun 18, 2026. Accessed Oct 19, 2026.
OZEMPIC (semaglutide) injection, for subcutaneous use - Full Prescribing Information (SPL). Novo Nordisk / National Library of Medicine DailyMed, Jun 1, 2026. Accessed Oct 19, 2026.
FDA clarifies policies for compounders as national GLP-1 supply begins to stabilize. U.S. Food and Drug Administration, Apr 1, 2026. Accessed Oct 19, 2026.

Printed from GLP Ladder. To recreate this result, open https://glpladder.com/tools/semaglutide-reconstitution/

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