Free semaglutide reconstitution calculator. Enter vial size (2-10 mg), BAC water volume, and weekly dose to get concentration, syringe units, and doses per vial. Includes the 5-tier dose escalation schedule (0.25-2.4 mg weekly), unit conversion reference, and B12 compound guidance. Verify semaglutide quality with independent lab test data on Peptigrity.
The FDA-approved dose escalation for semaglutide (Ozempic for type 2 diabetes, Wegovy for weight management) starts at 0.25 mg once weekly and increases every 4 weeks. Compounded lyophilised semaglutide follows the same tiers - the difference is manual reconstitution and syringe measurement.
| Escalation Tier | Weekly Dose | Weeks | At 2.5 mg/mL | At 5 mg/mL |
|---|---|---|---|---|
| Tier 1 (starting) | 0.25 mg | Weeks 1-4 | 10 units | 5 units |
| Tier 2 | 0.5 mg | Weeks 5-8 | 20 units | 10 units |
| Tier 3 | 1.0 mg | Weeks 9-12 | 40 units | 20 units |
| Tier 4 | 1.7 mg | Weeks 13-16 | 68 units | 34 units |
| Tier 5 (Wegovy max) | 2.4 mg | Week 17+ | 96 units | 48 units |
At 5 mg/mL, the 0.25 mg starting dose requires only 5 units - at the lower limit of measurability. A 30-unit syringe provides finer graduation marks. At 2.5 mg/mL (5 mg vial + 2 mL BAC water), the starting dose is a comfortable 10 units and all tiers fit within a 100-unit syringe.
Step 1 - Choose BAC Water Volume. Use 2.5 mg/mL as the default concentration. At this level, the 0.25 mg starting dose equals 10 units - easy to measure on any syringe. The BAC water calculator recommends volumes based on your dose and syringe.
Step 2 - Reconstitute. Swab both vial stoppers with alcohol. Inject BAC water slowly against the inside glass wall. Semaglutide dissolves within 1-2 minutes of gentle swirling. Solution should be clear and colourless. See reconstituting peptides step by step.
Step 3 - Store. Refrigerate at 2-8°C. Stable for approximately 28 days. See how to store peptides.
| Vial Size | At 0.25 mg/wk | At 0.5 mg/wk | At 1.0 mg/wk | At 2.4 mg/wk | Best For |
|---|---|---|---|---|---|
| 2 mg | 8 weeks | 4 weeks | 2 weeks | <1 week | Starting dose / trial |
| 3 mg | 12 weeks | 6 weeks | 3 weeks | ~1.25 weeks | Tier 1-2 |
| 5 mg | 20 weeks | 10 weeks | 5 weeks | ~2 weeks | Most popular |
| 10 mg | 40 weeks | 20 weeks | 10 weeks | ~4 weeks | Extended protocols |
Reconstituted semaglutide lasts approximately 28 days. Select a vial size that aligns with your 28-day consumption. For price comparisons, use the cost-per-dose calculator.
| Dose | At 2.5 mg/mL | At 5 mg/mL |
|---|---|---|
| 0.25 mg | 10 units | 5 units |
| 0.5 mg | 20 units | 10 units |
| 1.0 mg | 40 units | 20 units |
| 1.7 mg | 68 units | 34 units |
| 2.0 mg | 80 units | 40 units |
| 2.4 mg | 96 units | 48 units |
Formula: Units = (Dose in mg ÷ Concentration in mg/mL) × 100. For a detailed walkthrough, see the how to calculate peptide doses guide.
Some compounding pharmacies add vitamin B12 (cyanocobalamin) to semaglutide, giving the solution a distinctive pink or red colour. This is normal. B12 is added as a supplement, not a pharmacological synergist. The dosing math for semaglutide remains identical. Enter the semaglutide milligrams on the vial label (not the B12 amount) as the vial size.
| Factor | Semaglutide | Tirzepatide |
|---|---|---|
| Receptor targets | GLP-1 only | Dual: GIP + GLP-1 |
| Starting dose | 0.25 mg weekly | 2.5 mg weekly |
| Maximum dose | 2.4 mg weekly | 15 mg weekly |
| Common vial sizes | 2, 3, 5, 10 mg | 5, 10, 15, 30, 60 mg |
| Common concentration | 2.5-5 mg/mL | 5-15 mg/mL |
For a tirzepatide-specific calculator, see the tirzepatide calculator. For a full comparison, see comparing semaglutide and tirzepatide.
Semaglutide is one of the most counterfeited peptides in the research market due to its high demand and brand-name recognition (Ozempic, Wegovy). Quality verification before reconstitution is essential.
3 verification steps:
1. Check the Certificate of Analysis. The vendor's CoA should show HPLC purity of ≥97% and mass spectrometry identity confirmation matching semaglutide's molecular weight of 4,113.58 Da. Semaglutide contains a C18 fatty diacid linker - mass spec should confirm this modification. For guidance on interpreting CoAs, see red flags in peptide certificates of analysis.
2. Cross-reference against independent lab tests. Vendor CoAs are self-reported. Independent third-party test data published on Peptigrity's lab test results are community-submitted and verified by accredited laboratories. Check whether the vendor has independent semaglutide test data before purchasing.
3. Inspect the powder. Semaglutide lyophilised powder should be white to off-white, dry, and form a compact cake or loose powder. Discolouration (yellow, brown) or wet clumping suggests degradation or improper manufacturing. For a complete pre-purchase quality framework, see how to verify peptide quality before you buy.
| Tool | What It Does |
|---|---|
| Peptide Reconstitution Calculator | Standard calculator for all 30+ peptides |
| Tirzepatide Calculator | Tirzepatide-specific with 6-tier titration schedule |
| Retatrutide Calculator | Retatrutide-specific with Phase 2/3 titration |
| Cost-per-Dose Calculator | Compare semaglutide costs across vendors |
| BAC Water Calculator | Optimal BAC water volume for your vial and dose |
| Purity Comparison Tool | Compare lab-tested purity across brands |
At 2.5 mg/mL (5 mg vial + 2 mL BAC water): 0.25 mg = 10 units. At 5 mg/mL (5 mg vial + 1 mL): 0.25 mg = 5 units. The 2.5 mg/mL concentration provides more measurable draws and is recommended as the default.
2 mL produces 2.5 mg/mL - every dose tier from 0.25 mg (10 units) through 2.4 mg (96 units) fits within a 100-unit syringe. 1 mL produces 5 mg/mL - smaller draws but the 0.25 mg starting dose drops to 5 units, difficult to measure accurately. The BAC water calculator recommends volumes based on your dose and syringe.
The colour indicates vitamin B12 (cyanocobalamin) was added to the formulation. This is normal. Plain semaglutide without B12 reconstitutes to a clear, colourless solution. If your plain semaglutide produces a coloured solution, discard it.
Approximately 28 days at 2-8°C in bacteriostatic water. Unreconstituted powder at -20°C maintains integrity for months. See how to store peptides.
All three contain the same 31-amino-acid GLP-1 receptor agonist. Ozempic is FDA-approved for type 2 diabetes. Wegovy is approved for weight management. Both ship as pre-filled pens. Compounded semaglutide is produced by pharmacies under FDA 503A/503B regulations as lyophilised powder requiring reconstitution.
This calculator is for educational and research purposes only and does not constitute medical advice. Semaglutide is an FDA-approved prescription medication (Ozempic, Wegovy, Rybelsus). Compounded semaglutide is produced under FDA 503A/503B regulations and requires a prescription. Always consult a qualified healthcare provider for dosing guidance. Peptigrity is an independent review platform and does not sell, endorse, or recommend specific products or vendors.