How to Reconstitute 5mg Semaglutide (and 10mg, 20mg): Complete Mixing Guide (2026)

## Semaglutide Reconstitution: What Nobody Explains Clearly If you received a vial of white powder from your compounding pharmacy, you are holding lyophilized (freeze-dried) semaglutide. Before you can inject it, you need to dissolve it in bacteriostatic water to create a sterile liquid solution. The process takes less than five minutes — but the details matter enormously. Get the water-to-powder ratio wrong and every dose you draw will be miscalculated. Mix too aggressively and you can degrade the peptide. Use the wrong type of water and you create contamination risk. This guide covers everything you need to do it right, the first time. --- ## What You Need Gather everything before opening any vial: - **Semaglutide vial** (lyophilized powder — white or off-white) - **Bacteriostatic water (BAC water)** — NOT sterile water, NOT saline - **3mL syringe** with needle (for measuring and transferring BAC water) - **Insulin syringes** (29–31 gauge, ½ inch) for weekly injections - **Alcohol swabs** (70% isopropyl) - **Marker** for labeling - **Clean, flat workspace** with good lighting - **Sharps container** --- ## Choosing Your Concentration This is the most important decision in the reconstitution process. Your concentration determines how many units you draw per dose. Choose one and stick with it for the life of the vial. ### Recommended: 5mg/mL (Most Common) | Vial Size | BAC Water to Add | Concentration | Volume per 0.5mg Dose | |-----------|-----------------|---------------|-----------------------| | 5mg | 1.0mL | 5mg/mL | 0.10mL | | 10mg | 2.0mL | 5mg/mL | 0.10mL | | 20mg | 4.0mL | 5mg/mL | 0.10mL | At 5mg/mL, each 10 units on an insulin syringe equals 0.5mg — making dose calculations clean and straightforward. ### Alternative: 2.5mg/mL (Better for Low Doses) | Vial Size | BAC Water to Add | Concentration | Volume per 0.5mg Dose | |-----------|-----------------|---------------|-----------------------| | 5mg | 2.0mL | 2.5mg/mL | 0.20mL | | 10mg | 4.0mL | 2.5mg/mL | 0.20mL | This lower concentration produces larger injection volumes — easier to measure precisely, but more volume per shot. Good choice during the 0.25mg starting dose phase. --- ## Step-by-Step: How to Reconstitute Semaglutide ### Step 1: Prepare Your Workspace Wash hands thoroughly with soap and water for 20+ seconds. Wipe the work surface with an alcohol swab or clean cloth. Lay out all supplies. Allow the semaglutide vial to come to room temperature if it has been refrigerated — about 15–20 minutes. Cold powder dissolves slower and may not fully reconstitute. ### Step 2: Calculate Your BAC Water Volume Based on your vial size and desired concentration (use the tables above), confirm exactly how much bacteriostatic water you need. Write it down before you draw — do not rely on memory. **Quick formula:** BAC water (mL) = Vial size (mg) ÷ Target concentration (mg/mL) ### Step 3: Clean Both Vial Stoppers Remove the plastic flip-cap from the semaglutide vial and the BAC water vial. Using a fresh alcohol swab for each, wipe the rubber stoppers in a firm, single-direction motion. Let both air-dry for at least 20–30 seconds. Do not touch the cleaned surfaces. ### Step 4: Draw the Bacteriostatic Water Insert the needle of your 3mL syringe through the BAC water vial stopper. Invert the BAC water vial and slowly draw your calculated volume. Hold the syringe up to the light to verify the measurement precisely. Tap and expel any air bubbles back into the vial. ### Step 5: Add Water to the Semaglutide Vial (Critical Technique) This step determines whether you get a clean solution or a foamy mess. Insert the needle through the semaglutide vial stopper at a slight angle, aiming the tip toward the **inner glass wall** — not directly at the powder. Depress the plunger very slowly, letting the water trickle down the glass side of the vial. The powder should begin dissolving from the edges inward. Shooting directly onto the peptide can create foam and mechanically stress the protein structure. ### Step 6: Dissolve — No Shaking Set the vial on the counter and wait 1–2 minutes. The powder should dissolve on its own. If any solid remains, **gently roll** the vial between your palms for 10–15 seconds. Repeat until clear. **Never shake.** Shaking denatures peptide bonds and can reduce potency. If foam appears, set the vial aside for 15 minutes and let it settle before checking clarity. ### Step 7: Inspect the Solution Hold the vial up to a light source and examine the solution from multiple angles. It should be: - ✅ Clear — not hazy or cloudy - ✅ Colorless — no yellow, brown, or pink tint - ✅ Free of visible particles, fibers, or floaters - ✅ Fully dissolved — no powder remaining on glass If any of these criteria are not met, **do not inject.** Contact your compounding pharmacy. ### Step 8: Label and Refrigerate Immediately write on the vial: - Reconstitution date - Concentration (e.g., "5mg/mL") - Use-by date (28 days from today) Place in the refrigerator within 5 minutes of reconstitution. --- ## Dose Calculator: 5mg/mL Concentration At the standard 5mg/mL concentration, here is how each semaglutide dose translates to volume and insulin syringe units: | Semaglutide Dose | Volume (mL) | Insulin Syringe Units | Common Use | |-----------------|-------------|----------------------|------------| | 0.25mg | 0.05mL | 5 units | Starting dose, weeks 1–4 | | 0.5mg | 0.10mL | 10 units | Dose escalation, weeks 5–8 | | 1.0mg | 0.20mL | 20 units | Therapeutic dose | | 1.7mg | 0.34mL | 34 units | High dose | | 2.0mg | 0.40mL | 40 units | High dose | | 2.4mg | 0.48mL | 48 units | Maximum dose (Wegovy equivalent) | **Formula:** Dose (mg) ÷ Concentration (mg/mL) = Volume (mL). Multiply by 100 for syringe units. --- ## Dose Calculator: 2.5mg/mL Concentration | Semaglutide Dose | Volume (mL) | Insulin Syringe Units | |-----------------|-------------|----------------------| | 0.25mg | 0.10mL | 10 units | | 0.5mg | 0.20mL | 20 units | | 1.0mg | 0.40mL | 40 units | | 1.7mg | 0.68mL | 68 units | | 2.4mg | 0.96mL | 96 units | --- ## 5mg Semaglutide Reconstitution (Most Common Vial Size) The 5mg vial is the standard starter size, typically lasting 4–10 weeks depending on your dose. **Quick answer:** Add **1.0mL of bacteriostatic water** to a 5mg semaglutide vial for the standard 5mg/mL concentration. Each 10 units on an insulin syringe will then deliver 0.5mg of semaglutide. | Concentration | BAC Water | Doses at 0.5mg | Doses at 1.0mg | |---------------|-----------|----------------|----------------| | 5mg/mL (recommended) | 1.0mL | 10 doses | 5 doses | | 2.5mg/mL | 2.0mL | 10 doses | 5 doses | **Best practice:** Use 1.0mL BAC water (5mg/mL). Each weekly dose from 0.25mg–2.4mg draws less than 0.5mL, keeping injection volume comfortable. Add water slowly down the inner wall of the vial — never directly onto the powder — to avoid foaming and protein denaturation. **Common 5mg vial doses:** - 0.25mg starting dose → 0.05mL → 5 insulin units (lasts ~20 weeks per vial) - 0.5mg dose escalation → 0.10mL → 10 units - 1.0mg therapeutic dose → 0.20mL → 20 units - 2.4mg maximum (Wegovy equivalent) → 0.48mL → 48 units ## How to Reconstitute Other Semaglutide Vial Sizes ### 10mg Semaglutide Vial The 10mg vial provides better economy and fewer vial changes. | Concentration | BAC Water | Doses at 1.0mg | Doses at 2.4mg | |---------------|-----------|----------------|----------------| | 5mg/mL | 2.0mL | 10 doses | ~4 doses | | 2.5mg/mL | 4.0mL | 10 doses | ~4 doses | **Best practice:** 2.0mL BAC water gives a clean 5mg/mL concentration. Simple math, consistent dosing. ### 20mg Semaglutide Vial The 20mg vial is the best value per milligram for patients on stable maintenance doses. | Concentration | BAC Water | Doses at 1.0mg | Doses at 2.4mg | |---------------|-----------|----------------|----------------| | 5mg/mL | 4.0mL | 20 doses | ~8 doses | | 2.5mg/mL | 8.0mL | 20 doses | ~8 doses | **Note:** At 4mL+ of liquid, ensure you have a large enough syringe (5mL or two separate 3mL draws) to transfer all the BAC water accurately. --- ## Storage Rules After Reconstitution | Condition | Temperature | Maximum Duration | |-----------|-------------|-----------------| | Refrigerator (ideal) | 36–46°F (2–8°C) | 28 days from reconstitution | | Room temperature (brief excursion) | Under 77°F (25°C) | 2 hours maximum | | Frozen | Below 32°F | Never — discard immediately | **Storage do's:** - Store in the original vial, upright - Keep in the refrigerator door shelf or middle shelf — avoid the back where freezing can occur - Protect from light (store in original box or wrap in foil) - Remove from fridge just before drawing your dose; return within 5 minutes --- ## Before Every Injection: Quick Checklist Each time you draw from the reconstituted vial: 1. Is the solution clear and colorless? (Discard if cloudy or discolored) 2. Is it within 28 days of reconstitution? (Check your label) 3. Was it kept refrigerated? (Any extended room-temperature exposure degrades potency) 4. Is your dose calculation correct? (Double-check volume vs. concentration) 5. Are you using a fresh insulin syringe with a new needle? --- ## Common Mistakes and How to Avoid Them **Using the wrong water type:** Bacteriostatic water contains benzyl alcohol as a preservative. Sterile water does not. Without a preservative, a multi-use vial is a contamination risk after the first draw. **Shaking the vial:** Rolling gently is the correct technique. Shaking creates foam and can denature the peptide. If you accidentally shook it, let the solution settle for 15–20 minutes before inspecting. **Skipping the room-temperature step:** Cold powder dissolves poorly and may leave undissolved particles that look like contamination. Let the vial sit at room temperature for 15–20 minutes before adding water. **Not labeling the vial:** Two weeks from now you will not remember when you reconstituted it. Label every vial immediately with date, concentration, and expiry. **Drawing directly onto the powder:** Always aim the needle toward the glass wall. Let water trickle down rather than jet onto the peptide cake. --- ## Injecting Your Dose Once your vial is reconstituted and stored, drawing a weekly dose takes about 60 seconds. For a complete injection tutorial — including site rotation and technique — see our [semaglutide injection guide](/guides/semaglutide-injection-sites-abdomen-thigh-arm). For the full titration schedule and when to increase your dose, see our [semaglutide dosing schedule guide](/guides/semaglutide-dosing-schedule-week-by-week-guide). Quick summary: 1. Wipe the vial stopper with a fresh alcohol swab; let dry 2. Draw air equal to your dose volume into the syringe 3. Insert needle, inject air into vial (equalizes pressure) 4. Invert vial and draw your dose slowly 5. Verify volume, expel any air bubbles 6. Inject subcutaneously at a clean, rotated site — abdomen, thigh, or upper arm For how to manage any side effects during titration, see our [semaglutide side effects guide](/guides/semaglutide-side-effects-how-to-manage). --- *This guide covers compounded semaglutide reconstitution and is for educational purposes only. Always follow the specific instructions provided by your [compounding pharmacy](/oem) and prescribing clinician — [find a clinic near you](/for-clinics). For current pricing, see our [semaglutide cost guide](/guides/semaglutide-cost-price-guide-2026).* --- ## References - [Ozempic (semaglutide) Prescribing Information](https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/209637s012lbl.pdf). *Novo Nordisk / FDA*, 2024. - [USP Chapter 797: Pharmaceutical Compounding — Sterile Preparations](https://www.usp.org/compounding/general-chapter-797). *United States Pharmacopeia*, 2023. - [Stability of GLP-1 Receptor Agonist Peptide Formulations Under Refrigerated Conditions](https://pubmed.ncbi.nlm.nih.gov/?term=GLP-1+peptide+stability+refrigerated+compounding). *International Journal of Pharmaceutical Compounding*, 2022.