Semaglutide Dosage Calculator

Semaglutide Dose Escalation Schedule - mg to Syringe Units

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.

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.

Where Each Semaglutide Amount Comes From - Label and Trials

Peptigrity does not recommend a dose; the amounts below are the approved label's and the doses studied in SUSTAIN-6, SURMOUNT-5 and STEP UP, each with its source. The label starts at 0.25 mg weekly and escalates over months to 2.4 mg weekly for weight management, with 7.2 mg approved in March 2026. Semaglutide is approved for chronic use, so this is maintenance therapy rather than a course. Which rung anyone is on, and when they move, belongs to their prescriber rather than to a chart.

The strengths themselves are documented: 0.5 and 1.0 mg weekly were the doses in SUSTAIN-6 (n=3,297), and 1.7 or 2.4 mg were the maximum tolerated doses semaglutide was given at in SURMOUNT-5. A “68-week” figure is a trial duration, not a treatment plan — STEP 1 stopped at 68 weeks because that was its design. The evidence behind each amount is set out in semaglutide: the nausea rate is 44.2%, not 73%.

The 7.2 mg Dose and a 10 mg/mL Concentration

At 5 mg/mL, 7.2 mg is 1.44 mL, or 144 units — more than a 1 mL barrel holds; at 2.5 mg/mL it is 288 units and will not fit either. The dose was approved in March 2026 on the strength of STEP UP, which randomised 1,407 participants and produced −20.7% at 72 weeks against −17.5% on 2.4 mg and −2.4% on placebo. The table below gives each documented amount in U-100 units at 10 mg/mL, the concentration that holds the top dose; the 2.5 and 5 mg/mL figures are in the tables above.

No single concentration serves the whole ladder. A 2.5 mg/mL preparation reads the starting dose well and cannot deliver the top one; a 10 mg/mL preparation holds the top dose comfortably and reduces the starting dose to a smear between marks. The worked example below puts the same 7.2 mg at two concentrations.

The wrong response to the left-hand column is to split the dose across two draws and hope the total is right. The right response happens earlier, at the point the diluent goes in: the diluent volume is the only variable here you fully control, it is irreversible once added, and it should be chosen against the rung you are on rather than the rung you started at. Whether 7.2 mg is an appropriate amount for any individual is a prescriber's question and this page does not touch it.

How to Reconstitute Semaglutide

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.

Common Semaglutide Vial Sizes - Which to Buy

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.

Semaglutide Unit Conversion Quick Reference

Formula: Units = (Dose in mg ÷ Concentration in mg/mL) × 100. For a detailed walkthrough, see the how to calculate peptide doses guide.

When the Vial Holds Less Than the Label Says

Every figure above assumes the vial contains what the label says. A vial can be 99% pure and still hold substantially less peptide than claimed, because purity is a proportion and net content is a quantity. The worked example below carries an illustrative shortfall through the same 48-unit draw.

The 8.5 mg figure in that right-hand column is an illustration, not a measurement. Peptigrity does not publish a fill-variance range for semaglutide, because our fact base does not carry one. Where a net-content figure exists for your batch, calculate from the assay rather than from the label; see why 10 mg isn't 10 mg. The reverse dose calculator runs the check backwards, from a draw you have already made to the amount it delivered.

Semaglutide Unit-Conversion Errors

FDA has received “multiple reports of adverse events... that may be related to dosing errors associated with compounded injectable semaglutide products”; as of 30 November 2024 it had received more than 392 adverse event reports for compounded semaglutide. Those are spontaneous reports rather than trial data. The errors below account for most of the damage, and they are not equally visible.

• “48 units” treated as a dose rather than a volume. A unit is 0.01 mL and nothing else. At 2.5 mg/mL the same 48 units delivers 1.2 mg, not 2.4 mg.
• Units quoted with no concentration attached. The figure cannot be used, and it cannot be corrected. Ask for the vial size and the diluent volume, or discard the figure.
• The multiplication by 100 dropped. Millilitres and units differ by two decimal places, and the resulting draw is either physically impossible or a hundredth of the intention.
• Concentration changed mid-vial. Topping up an open vial with more diluent invalidates every unit figure calculated before it. Write the concentration and the date on the vial when you mix it.
• A 7.2 mg dose split across two draws without recording it. Two partial volumes are two chances to misread a barrel, and the total is unverifiable afterwards.
• A dose landing below roughly two units. Graduations stop being informative there. The fix is a different concentration, decided before mixing, not a steadier hand.
• Assuming the label milligram is a peptide milligram. That assumption sits upstream of every figure on this page.

Reverse check: units ÷ 100 × concentration should return your dose; any answer that does not match means one of the three inputs is wrong. Injection-technique errors — reusing a transfer needle, injecting into a reactive site, recapping a sharp — are covered in how to inject peptides.

B12 and Semaglutide Compounds - What to Know

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.

Semaglutide vs Tirzepatide - Dosing Differences

For a tirzepatide-specific calculator, see the tirzepatide calculator. For a full comparison, see comparing semaglutide and tirzepatide.

How to Verify Semaglutide Quality Before Reconstituting

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.