Semaglutide Dose Calculator: How to Measure Your Weekly Injection

Calculate semaglutide doses in insulin syringe units and understand the Wegovy and Ozempic dose escalation schedules.

What Is Semaglutide?

Semaglutide is a GLP-1 receptor agonist used for Type 2 diabetes (brand: Ozempic) and chronic weight management (brand: Wegovy). It mimics the incretin hormone GLP-1, slowing gastric emptying, reducing appetite, and improving glycemic control. Its long half-life of approximately 168 hours (7 days) allows once-weekly dosing.

FDA-Approved Dose Escalation: Wegovy

The Wegovy schedule is designed to minimize GI side effects by slowly increasing the dose over 16 weeks:

• Weeks 1-4: 0.25 mg/week (initiation dose)

• Weeks 5-8: 0.5 mg/week

• Weeks 9-12: 1.0 mg/week

• Weeks 13-16: 1.7 mg/week

• Week 17+: 2.4 mg/week (maintenance dose)

Do not skip escalation steps. If you experience persistent nausea, remain on your current dose for an additional 4 weeks before escalating.

Compounded semaglutide dose conversion chart showing common vial strengths, BAC water volumes, concentrations, and syringe units for doses from 0.25 to 2.4 mg — Quick reference for converting compounded semaglutide vial concentrations to insulin syringe units.

How to Calculate Syringe Units for Compounded Semaglutide

Compounded semaglutide typically comes as a lyophilized powder. After reconstitution, use this formula:

Concentration (mg/mL) = Vial content (mg) ÷ BAC water added (mL)

Units to draw = Dose (mg) ÷ Concentration (mg/mL) × Syringe units per mL

Example: You have a 5 mg vial reconstituted with 2.5 mL of BAC water. Concentration = 2 mg/mL. For a 0.25 mg dose using a 100-unit syringe: Units = 0.25 ÷ 2 × 100 = 12.5 units (round to 13 units).

Injection Technique

• Inject subcutaneously in the abdomen, thigh, or upper arm

• Rotate injection sites weekly to prevent lipodystrophy

• Inject at the same time each week (± 2 days if you miss a dose)

• Store reconstituted solution at 2-8°C

Side Effect Management

The most common side effects are gastrointestinal: nausea (44%), diarrhea (30%), vomiting (24%). These typically improve after 4-8 weeks as your body adjusts.

Mitigation strategies: eat smaller, more frequent meals; avoid high-fat or spicy foods; stay hydrated; and slow down your dose escalation if symptoms are severe.

Clinical Efficacy

In the STEP 1 trial (n=1,961), patients on Wegovy 2.4 mg lost an average of 14.9% body weight vs. 2.4% with placebo over 68 weeks. Approximately 86% of participants achieved ≥5% weight loss.

Source: Wilding JPH, et al. N Engl J Med. 2021;384:989-1002. DOI: 10.1056/NEJMoa2032183

❓ Frequently Asked Questions

How do I calculate semaglutide units for a compounded vial?▼

Divide vial strength (mg) by water volume (mL) to get concentration. Then: units to draw = desired dose (mg) ÷ concentration (mg/mL) × 100. For a 5 mg/2.5 mL vial: 2 mg/mL. For a 0.5 mg dose: 0.5 ÷ 2 × 100 = 25 units.

What is the semaglutide dose escalation schedule?▼

Wegovy protocol: 0.25 mg × 4 weeks → 0.5 mg × 4 weeks → 1 mg × 4 weeks → 1.7 mg × 4 weeks → 2.4 mg maintenance. Compounded semaglutide often follows the same schedule. Use our GLP-1 Scheduler.

How is compounded semaglutide different from Ozempic?▼

The active molecule is the same. Compounded semaglutide is prepared by licensed compounding pharmacies at custom concentrations, often requiring reconstitution with BAC water. Branded Ozempic comes in pre-filled pens at fixed concentrations.

What syringe should I use for semaglutide?▼

A 100-unit (1 mL) insulin syringe is standard for most semaglutide concentrations. For very small doses during escalation, a 50-unit syringe provides finer precision. Never use a standard non-insulin syringe.