Compounded Semaglutide: Reconstitution, Units, and Dose Escalation

Compounded semaglutide: what you're working with

Compounded semaglutide is available from licensed compounding pharmacies in two forms: lyophilized powder vials (reconstitute with bacteriostatic water) and pre-mixed solution vials (ready to inject). The reconstitution process applies only to powder vials.

Compounded semaglutide is distinct from brand-name Ozempic (injection pen, 0.5/1/2 mg doses) and Wegovy (injection pen, 0.25–2.4 mg doses). Compounded versions typically come in higher-concentration multi-dose vials. Your compounding pharmacy label is the authoritative reference for your specific vial's concentration and beyond-use date.

Reconstitution steps (powder vials)

1. Remove vial from refrigerator. Allow to reach room temperature for 10–15 minutes — injecting cold bac water into a cold peptide powder can cause clumping.
2. Clean the vial stopper with an alcohol swab. Allow to dry completely before inserting a needle.
3. Draw the prescribed volume of bacteriostatic water into a syringe. For most semaglutide powder vials: 1–2 mL bac water (your pharmacy label specifies the correct volume — do not guess).
4. Insert the needle through the stopper at an angle and inject the bac water slowly down the inside wall of the vial. Do not inject directly onto the powder cake — this can degrade the peptide.
5. Do not shake. Gently swirl or roll the vial until the powder dissolves completely. The resulting solution should be clear and colorless. Discard if cloudy or particulate is visible.
6. Label the vial with the reconstitution date. Refrigerate immediately. Do not freeze.

Concentration and dose calculation

Semaglutide concentrations vary by compounding pharmacy and vial size. Common setups:

The formula: Units = (Dose mg ÷ Vial strength mg) × Bac water mL × 100. Use the reconstitution calculator for your specific vial and dose — it handles the unit math for any combination.

Semaglutide dose escalation schedule

Semaglutide is started at low doses and escalated every 4 weeks to allow GI tolerance to develop. The standard escalation (Wegovy) mirrors FDA labeling:

Compounded protocols sometimes use a modified escalation (e.g., starting at 0.5 mg or escalating more slowly). Your prescribing provider determines your schedule — do not self-escalate.

Half-life and steady state

Semaglutide has a ~7-day half-life — the longest of the major GLP-1 agonists. With weekly dosing, steady state is reached after approximately 4–5 half-lives, meaning 4–5 weeks of weekly injections. At steady state, active concentrations are approximately 1.5–2× higher than after the first dose.

This explains why GI side effects often peak in weeks 2–4 (accumulating toward steady state) and then stabilize. It also explains why the dose-escalation protocol waits 4 weeks between steps — you need to be at steady state to accurately assess tolerability at the current dose.

After stopping semaglutide, approximately 97% is cleared after 5 half-lives (~35 days). For surgical planning or starting medications with interactions, 5 weeks is the typical washout guidance — confirm with your provider.

Storage

Lyophilized (powder) semaglutide vials: refrigerate (2–8°C) until reconstitution. Reconstituted vials: refrigerate, use within the beyond-use date on the pharmacy label (typically 28–30 days). Do not freeze reconstituted solutions. Keep away from light.

Pre-mixed semaglutide solution vials: follow pharmacy label exactly. These typically have a different beyond-use date and may have specific handling requirements.

Semaglutide vs. tirzepatide: which to track

If you're deciding between semaglutide and tirzepatide, see the full tirzepatide vs. semaglutide comparison. From a reconstitution and tracking perspective, the two are structurally similar — both are weekly subcutaneous injections with dose escalation protocols and half-life accumulation curves. The main differences are mechanism (GLP-1 only vs. dual GIP/GLP-1), maximum dose, and total weight loss achieved in trials.