Semaglutide Reconstitution Calculator
Enter your semaglutide vial size and the amount of bacteriostatic water you added to instantly calculate concentration, injection volume, and syringe units for any dose.
Semaglutide Dose Reference Table
Pre-calculated injection volumes for a standard 5mg semaglutide vial reconstituted with 2ml of bacteriostatic water (concentration: 2500 mcg/ml). Use the calculator above for different vial sizes or BAC water amounts.
| Dose | Inject Volume (ml) | Syringe Units (100u syringe) | Common Use |
|---|---|---|---|
| 250 mcg | 0.10 ml | 10 units | Starting / titration dose |
| 500 mcg | 0.20 ml | 20 units | Common maintenance dose |
| 750 mcg | 0.30 ml | 30 units | Mid-range dose |
| 1000 mcg (1 mg) | 0.40 ml | 40 units | Higher maintenance |
| 1700 mcg (1.7 mg) | 0.68 ml | 68 units | Escalated dose |
| 2400 mcg (2.4 mg) | 0.96 ml | 96 units | Maximum weekly dose |
All values calculated at 2500 mcg/ml concentration (5mg vial + 2ml BAC water). Adjust for your reconstitution using the calculator above.
About Semaglutide
Semaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist originally developed for the treatment of type 2 diabetes and, more recently, chronic weight management. It works by mimicking the action of the natural GLP-1 hormone, which stimulates insulin secretion in response to meals, suppresses glucagon, slows gastric emptying, and reduces appetite through central nervous system signaling.
When used as a research peptide (reconstituted from lyophilized powder), semaglutide is administered via weekly subcutaneous injection. Typical starting doses range from 250–500 mcg per week, with gradual titration upward to reduce gastrointestinal side effects such as nausea, vomiting, and diarrhea. Common maintenance doses range from 500 mcg to 2400 mcg (2.4 mg) per week.
The peptide has a half-life of approximately 5–7 days, making once-weekly dosing appropriate and effective for maintaining stable blood levels. Semaglutide is stable as a reconstituted solution for up to 28 days when stored in the refrigerator at 2–8°C with bacteriostatic water as the solvent.
Proper reconstitution is essential for accurate dosing. A 5mg vial reconstituted with 2ml of bacteriostatic water yields a concentration of exactly 2500 mcg/ml, which is the most common preparation used for research purposes. Always inject the BAC water slowly down the inner wall of the vial and swirl gently — never shake — to avoid denaturing the peptide.
Frequently Asked Questions
To reconstitute a 5mg semaglutide vial, draw 2ml of bacteriostatic water into a syringe and inject it slowly down the side of the vial — never directly onto the powder. This gives you a concentration of 2500 mcg/ml. Gently swirl (do not shake) until the powder is fully dissolved. The resulting solution should be clear and colorless. Store reconstituted semaglutide in the refrigerator at 2–8°C.
The most common reconstitution for semaglutide is 2ml of bacteriostatic water per 5mg vial, giving a concentration of 2500 mcg/ml. Some practitioners use 1ml (resulting in 5000 mcg/ml) for lower injection volumes, or up to 4ml for easier measurement of smaller doses. The amount you choose affects the concentration and therefore the injection volume for each dose — use the calculator above to find the exact volumes for your chosen BAC water amount.
On a standard 1ml insulin syringe marked in 100 units, ".5" refers to 50 units (halfway up the syringe). At the standard 2500 mcg/ml concentration (5mg vial + 2ml BAC water), 50 units = 0.5ml = 1250 mcg of semaglutide. If your concentration is different, use this calculator to convert your specific dose to the correct syringe marking.
Reconstituted semaglutide should be stored in the refrigerator at 2–8°C (36–46°F). Keep it in the original vial with the rubber stopper intact. Avoid freezing, direct sunlight, or excessive heat. Do not store it in the door of the refrigerator where temperatures fluctuate. Always check the solution before each use — discard if cloudy, discolored, or if particles are visible.
Reconstituted semaglutide with bacteriostatic water is generally considered stable for up to 28 days when refrigerated at 2–8°C. Bacteriostatic water contains 0.9% benzyl alcohol as a preservative, which extends the usable life compared to sterile water. Always label your vial with the reconstitution date and discard after 28 days, or sooner if the solution appears cloudy or discolored.