How many units is 0.25 mg of Semaglutide?

It depends entirely on how much water you added. In a 5 mg vial reconstituted with 2 mL, the concentration is 2.5 mg/mL, so 0.25 mg is 0.1 mL, which is 10 units on a U-100 insulin syringe. In the same vial with 1 mL of water it is 5 units, and with 3 mL it is 15 units.

How much bacteriostatic water for a 5 mg Semaglutide vial?

2 mL is the usual choice. It gives 2.5 mg/mL, which puts the commonly reported range of 0.1 mg to 2.4 mg between roughly 4 and 96 units. Aim for a draw between about 10 and 50 units, where the barrel is easiest to read, and add or remove water to get there.

How many doses are in a 5 mg vial?

Divide 5 by your dose. At 0.25 mg that is 20 doses, which at once weekly is 140 days.

Why are my units different from someone else's?

Because they used a different amount of water. Units are only meaningful alongside the vial strength and the water volume. Always state all three.

Semaglutide dosage calculator

Semaglutide doses are small, so the draw is small and the water volume matters more than with any other compound here. Put in your numbers and see where it lands.

IndependentThis site does not sell peptides and is not owned by a vendor. Every other calculator on page one of Google belongs to a shop.

The maths is openThe formula is written out on this page and the code behind it is a single file with an automated test suite.

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ReviewedDose ranges and half-life figures last checked 3 September 2026.

Dose to units, at the standard setup

Dose	Draw	U-100 units	Doses per vial	Vial lasts
0.25 mg	0.1 mL	10 units	20	140 days
0.5 mg	0.2 mL	20 units	10	70 days
1 mg	0.4 mL	40 units	5	35 days
1.7 mg	0.68 mL	68 units	2	14 days
2.4 mg	0.96 mL	96 units	2	14 days

Based on a 5 mg vial reconstituted with 2 mL of bacteriostatic water, which is 2.5 mg/mL, drawn on a standard U-100 insulin syringe, once weekly.

About the numbers above

Semaglutide is a GLP-1 receptor agonist. The licensed ladder is 0.25, 0.5, 1.0, 1.7 and 2.4 mg once weekly, stepping every four weeks, with 0.25 mg as a starting dose rather than a maintenance one.

Because 0.25 mg is a very small quantity, a 5 mg vial reconstituted with 2 mL puts that dose at 10 units. Reconstituting the same vial with only 1 mL halves it to 5 units, where a small misread is a large proportional error. This is the one compound where erring towards more water is usually the easier choice.

A 5 mg vial at different water volumes

If the draw feels awkward to read, change the water rather than the dose. The dose stays the same; only the mark moves.

Vial	BAC water	Concentration	Draw	U-100 units	Doses/vial
5 mg	1 mL	5 mg/mL	0.05 mL	5 units	20
5 mg	2 mL	2.5 mg/mL	0.1 mL	10 units	20
5 mg	3 mL	1.67 mg/mL	0.15 mL	15 units	20
10 mg	1 mL	10 mg/mL	0.025 mL	2.5 units	40
10 mg	2 mL	5 mg/mL	0.05 mL	5 units	40
10 mg	3 mL	3.33 mg/mL	0.075 mL	7.5 units	40

All rows above assume a 0.25 mg dose and a standard U-100 insulin syringe, where 100 units = 1 mL.

How long it stays in you

The half-life of Semaglutide is about 6.9 days. That is the time for the amount in your blood to halve, so after one half-life you are at 50 percent of the peak, after two you are at 25 percent, and after four you are at roughly 6 percent. This is why a weekly compound still has meaningful levels present when the next dose lands, and why levels build over the first several weeks before they settle.

Common questions

How many units is 0.25 mg of Semaglutide?: It depends entirely on how much water you added. In a 5 mg vial reconstituted with 2 mL, the concentration is 2.5 mg/mL, so 0.25 mg is 0.1 mL, which is 10 units on a U-100 insulin syringe. In the same vial with 1 mL of water it is 5 units, and with 3 mL it is 15 units.
How much bacteriostatic water for a 5 mg Semaglutide vial?: 2 mL is the usual choice. It gives 2.5 mg/mL, which puts the commonly reported range of 0.1 mg to 2.4 mg between roughly 4 and 96 units. Aim for a draw between about 10 and 50 units, where the barrel is easiest to read, and add or remove water to get there.
How many doses are in a 5 mg vial?: Divide 5 by your dose. At 0.25 mg that is 20 doses, which at once weekly is 140 days.
Why are my units different from someone else's?: Because they used a different amount of water. Units are only meaningful alongside the vial strength and the water volume. Always state all three.

Buying Semaglutide? The where to buy page lists the vendors this site uses and what to check before ordering, and Peptide Bureau keeps the ranked vendor scorecard.

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Read this before you use the numbers. This is a unit-conversion tool. It converts a vial strength and a volume of bacteriostatic water into a concentration, a draw volume and a mark on an insulin syringe. It does not tell you what to take, whether to take it, or whether a compound is safe for you. Most of the compounds listed here are sold for laboratory research use and are not approved for human use. Nothing on this site is medical advice. Dosing decisions belong with a licensed clinician who knows your history. Always confirm the strength printed on your own vial rather than trusting a preset.