Semaglutide Reconstitution Calculator

Semaglutide is a 31-amino-acid GLP-1 analog carrying a C18 fatty diacid side chain, supplied as a lyophilized powder. Its molecular weight (4,113.6 g/mol) is built into this calculator, so alongside the usual mass-per-volume figures it reports the molar concentration of the prepared solution. Enter the vial size and the volume of bacteriostatic water added to get the concentration, the amount in any measured volume, and how many aliquots a vial yields. For other compounds, use the general peptide calculator.

Semaglutide calculator

—Concentration

—per 0.1 mL (100 µL)

—molar concentration (MW 4,113.6 g/mol)

This tool does solution-concentration arithmetic for laboratory preparation records. It does not provide dosage guidance. Semaglutide is sold for research use only. It is not for human consumption, self-administration or therapeutic use.

Semaglutide vial concentration table

Worked math for each Semaglutide vial size in the catalog (2 mg, 5 mg, 10 mg, 20 mg) with 1, 2 and 3 mL of diluent. The figures come straight from concentration = mass ÷ volume. They are reference arithmetic, not a recommended preparation.

Vial	Diluent	Concentration	Per 0.1 mL	Molarity
Semaglutide 2 mg	1 mL	2 mg/mL	200 mcg	486 µM	Load ↑
Semaglutide 2 mg	2 mL	1 mg/mL	100 mcg	243 µM	Load ↑
Semaglutide 2 mg	3 mL	0.667 mg/mL	66.7 mcg	162 µM	Load ↑
Semaglutide 5 mg	1 mL	5 mg/mL	500 mcg	1.22 mM	Load ↑
Semaglutide 5 mg	2 mL	2.5 mg/mL	250 mcg	608 µM	Load ↑
Semaglutide 5 mg	3 mL	1.667 mg/mL	166.7 mcg	405 µM	Load ↑
Semaglutide 10 mg	1 mL	10 mg/mL	1,000 mcg	2.43 mM	Load ↑
Semaglutide 10 mg	2 mL	5 mg/mL	500 mcg	1.22 mM	Load ↑
Semaglutide 10 mg	3 mL	3.333 mg/mL	333.3 mcg	810 µM	Load ↑
Semaglutide 20 mg	1 mL	20 mg/mL	2,000 mcg	4.86 mM	Load ↑
Semaglutide 20 mg	2 mL	10 mg/mL	1,000 mcg	2.43 mM	Load ↑
Semaglutide 20 mg	3 mL	6.667 mg/mL	666.7 mcg	1.62 mM	Load ↑

Semaglutide compound data used in the math

Compound class	31-amino-acid acylated GLP-1 receptor agonist
Molecular weight	4,113.6 g/mol
Molecular formula	C₁₈₇H₂₉₁N₄₅O₅₉
CAS number	910463-68-2
Appearance	White to off-white lyophilized powder; clear, colorless solution
Storage	Lyophilized: −20 °C, desiccated, protected from light. Reconstituted: 2–8 °C.
Vial sizes	2 mg, 5 mg, 10 mg, 20 mg

Molar concentration (mM) = concentration (mg/mL) ÷ molecular weight (g/mol) × 1000. Every product ships with a certificate of analysis. See the Semaglutide product page or the COA portal.

Semaglutide reconstitution handling notes

Acylated GLP-1 analogs dissolve readily in bacteriostatic water at room temperature. Direct the diluent down the vial wall and swirl gently; foaming indicates the stream hit the powder too hard, and the foam should be allowed to settle before any volume is withdrawn.
With the smallest (2 mg) vial, small aliquots can fall below what a graduated syringe or pipette measures accurately. Adding more diluent makes the same aliquot a larger, more accurate volume without changing the amount of peptide in the vial.
The label figure is the nominal fill. The lot’s certificate of analysis reports measured purity; use it when a preparation record needs the net figure.

For the full bench procedure, including materials, technique, blend vials and storage before and after, see how to reconstitute peptides.

How to reconstitute Semaglutide

The worked example uses a 5 mg Semaglutide vial and 2 mL of bacteriostatic water. The same steps apply to any vial size or volume; only the resulting concentration changes.

Equilibrate and sanitize. Let the Semaglutide vial and the bacteriostatic water reach room temperature, then wipe both rubber stoppers with an alcohol swab.
Draw the diluent. With a sterile syringe, withdraw 2 mL of bacteriostatic water.
Add it slowly down the wall. Insert the needle through the Semaglutide vial’s stopper and let the water run down the inside of the glass, not directly onto the powder.
Swirl, don’t shake. Rotate the vial gently until the solution is completely clear and colorless. Cloudiness or particles after gentle mixing are a reason to check the lot’s certificate of analysis.
Label and store. Write the concentration on the vial: 5 mg ÷ 2 mL = 2.5 mg/mL (608 µM), plus the date and lot number. Storage: Lyophilized: −20 °C, desiccated, protected from light. Reconstituted: 2–8 °C.

Semaglutide reconstitution FAQ

What concentration does a 2 mg Semaglutide vial make with 2 mL of bacteriostatic water?

2 mg divided by 2 mL is 1 mg/mL, which is 100 mcg in every 0.1 mL. Using Semaglutide’s molecular weight of 4,113.6 g/mol, that is a molar concentration of 243 µM.

How much Semaglutide is in 0.1 mL after reconstitution?

It depends entirely on the concentration prepared. For example, a 5 mg vial reconstituted with 2 mL gives 2.5 mg/mL, so 0.1 mL contains 250 mcg. The same vial reconstituted with 1 mL would give twice that per 0.1 mL.

Does adding more bacteriostatic water change how much Semaglutide is in the vial?

No. The diluent volume only sets the concentration. The total Semaglutide in the vial is the same whatever volume is added. More diluent spreads it across a larger volume, so any given amount takes up more mL and is easier to measure accurately.

How should reconstituted Semaglutide be stored?

Lyophilized: -20 °C, desiccated, protected from light. Reconstituted: 2-8 °C. Label the vial with the compound, lot number, date and the concentration calculated here.